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eval.c revision 1.188.2.2
      1  1.188.2.2    martin /*	$NetBSD: eval.c,v 1.188.2.2 2024/11/25 10:24:57 martin Exp $	*/
      2       1.19       cgd 
      3        1.1       cgd /*-
      4        1.7       jtc  * Copyright (c) 1993
      5        1.7       jtc  *	The Regents of the University of California.  All rights reserved.
      6        1.1       cgd  *
      7        1.1       cgd  * This code is derived from software contributed to Berkeley by
      8        1.1       cgd  * Kenneth Almquist.
      9        1.1       cgd  *
     10        1.1       cgd  * Redistribution and use in source and binary forms, with or without
     11        1.1       cgd  * modification, are permitted provided that the following conditions
     12        1.1       cgd  * are met:
     13        1.1       cgd  * 1. Redistributions of source code must retain the above copyright
     14        1.1       cgd  *    notice, this list of conditions and the following disclaimer.
     15        1.1       cgd  * 2. Redistributions in binary form must reproduce the above copyright
     16        1.1       cgd  *    notice, this list of conditions and the following disclaimer in the
     17        1.1       cgd  *    documentation and/or other materials provided with the distribution.
     18       1.74       agc  * 3. Neither the name of the University nor the names of its contributors
     19        1.1       cgd  *    may be used to endorse or promote products derived from this software
     20        1.1       cgd  *    without specific prior written permission.
     21        1.1       cgd  *
     22        1.1       cgd  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     23        1.1       cgd  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     24        1.1       cgd  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     25        1.1       cgd  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     26        1.1       cgd  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     27        1.1       cgd  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     28        1.1       cgd  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     29        1.1       cgd  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     30        1.1       cgd  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     31        1.1       cgd  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32        1.1       cgd  * SUCH DAMAGE.
     33        1.1       cgd  */
     34        1.1       cgd 
     35       1.36  christos #include <sys/cdefs.h>
     36        1.1       cgd #ifndef lint
     37       1.19       cgd #if 0
     38       1.26  christos static char sccsid[] = "@(#)eval.c	8.9 (Berkeley) 6/8/95";
     39       1.19       cgd #else
     40  1.188.2.2    martin __RCSID("$NetBSD: eval.c,v 1.188.2.2 2024/11/25 10:24:57 martin Exp $");
     41       1.24       cgd #endif
     42        1.1       cgd #endif /* not lint */
     43        1.1       cgd 
     44       1.90      tron #include <stdbool.h>
     45       1.70       dsl #include <stdlib.h>
     46       1.21  christos #include <signal.h>
     47       1.69       agc #include <stdio.h>
     48      1.116  christos #include <string.h>
     49      1.100  christos #include <errno.h>
     50      1.105       dsl #include <limits.h>
     51       1.21  christos #include <unistd.h>
     52       1.76       dsl #include <sys/fcntl.h>
     53      1.129  christos #include <sys/stat.h>
     54       1.68  christos #include <sys/times.h>
     55       1.71     rafal #include <sys/param.h>
     56       1.61  christos #include <sys/types.h>
     57       1.61  christos #include <sys/wait.h>
     58       1.70       dsl #include <sys/sysctl.h>
     59       1.61  christos 
     60        1.1       cgd /*
     61        1.1       cgd  * Evaluate a command.
     62        1.1       cgd  */
     63        1.1       cgd 
     64        1.1       cgd #include "shell.h"
     65        1.1       cgd #include "nodes.h"
     66        1.1       cgd #include "syntax.h"
     67        1.1       cgd #include "expand.h"
     68        1.1       cgd #include "parser.h"
     69        1.1       cgd #include "jobs.h"
     70        1.1       cgd #include "eval.h"
     71        1.1       cgd #include "builtins.h"
     72        1.1       cgd #include "options.h"
     73        1.1       cgd #include "exec.h"
     74        1.1       cgd #include "redir.h"
     75        1.1       cgd #include "input.h"
     76        1.1       cgd #include "output.h"
     77        1.1       cgd #include "trap.h"
     78        1.1       cgd #include "var.h"
     79        1.1       cgd #include "memalloc.h"
     80        1.1       cgd #include "error.h"
     81       1.21  christos #include "show.h"
     82        1.1       cgd #include "mystring.h"
     83       1.64  christos #include "main.h"
     84       1.35  christos #ifndef SMALL
     85      1.114  christos #include "nodenames.h"
     86        1.7       jtc #include "myhistedit.h"
     87       1.11       cgd #endif
     88        1.1       cgd 
     89        1.1       cgd 
     90      1.168       kre STATIC struct skipsave s_k_i_p;
     91      1.168       kre #define	evalskip	(s_k_i_p.state)
     92      1.168       kre #define	skipcount	(s_k_i_p.count)
     93      1.168       kre 
     94      1.109  christos STATIC int loopnest;		/* current loop nesting level */
     95      1.109  christos STATIC int funcnest;		/* depth of function calls */
     96      1.103  christos STATIC int builtin_flags;	/* evalcommand flags for builtins */
     97      1.109  christos /*
     98      1.109  christos  * Base function nesting level inside a dot command.  Set to 0 initially
     99      1.109  christos  * and to (funcnest + 1) before every dot command to enable
    100      1.109  christos  *   1) detection of being in a file sourced by a dot command and
    101      1.109  christos  *   2) counting of function nesting in that file for the implementation
    102      1.109  christos  *      of the return command.
    103      1.109  christos  * The value is reset to its previous value after the dot command.
    104      1.109  christos  */
    105      1.109  christos STATIC int dot_funcnest;
    106        1.1       cgd 
    107        1.1       cgd 
    108       1.89      matt const char *commandname;
    109        1.1       cgd struct strlist *cmdenviron;
    110        1.1       cgd int exitstatus;			/* exit status of last command */
    111       1.68  christos int back_exitstatus;		/* exit status of backquoted command */
    112        1.1       cgd 
    113        1.1       cgd 
    114       1.68  christos STATIC void evalloop(union node *, int);
    115       1.68  christos STATIC void evalfor(union node *, int);
    116       1.68  christos STATIC void evalcase(union node *, int);
    117       1.68  christos STATIC void evalsubshell(union node *, int);
    118       1.68  christos STATIC void expredir(union node *);
    119      1.159       kre STATIC void evalredir(union node *, int);
    120       1.68  christos STATIC void evalpipe(union node *);
    121       1.68  christos STATIC void evalcommand(union node *, int, struct backcmd *);
    122       1.68  christos STATIC void prehash(union node *);
    123        1.1       cgd 
    124      1.109  christos STATIC char *find_dot_file(char *);
    125        1.1       cgd 
    126        1.1       cgd /*
    127        1.1       cgd  * Called to reset things after an exception.
    128        1.1       cgd  */
    129        1.1       cgd 
    130        1.1       cgd #ifdef mkinit
    131        1.1       cgd INCLUDE "eval.h"
    132        1.1       cgd 
    133        1.1       cgd RESET {
    134      1.109  christos 	reset_eval();
    135        1.1       cgd }
    136        1.1       cgd 
    137        1.1       cgd SHELLPROC {
    138        1.1       cgd 	exitstatus = 0;
    139        1.1       cgd }
    140        1.1       cgd #endif
    141        1.1       cgd 
    142      1.109  christos void
    143      1.109  christos reset_eval(void)
    144      1.109  christos {
    145      1.109  christos 	evalskip = SKIPNONE;
    146      1.109  christos 	dot_funcnest = 0;
    147      1.109  christos 	loopnest = 0;
    148      1.109  christos 	funcnest = 0;
    149      1.109  christos }
    150      1.109  christos 
    151       1.76       dsl static int
    152       1.76       dsl sh_pipe(int fds[2])
    153       1.76       dsl {
    154       1.76       dsl 	int nfd;
    155       1.76       dsl 
    156       1.76       dsl 	if (pipe(fds))
    157       1.76       dsl 		return -1;
    158       1.76       dsl 
    159       1.76       dsl 	if (fds[0] < 3) {
    160       1.76       dsl 		nfd = fcntl(fds[0], F_DUPFD, 3);
    161       1.76       dsl 		if (nfd != -1) {
    162       1.76       dsl 			close(fds[0]);
    163       1.76       dsl 			fds[0] = nfd;
    164       1.76       dsl 		}
    165       1.76       dsl 	}
    166       1.76       dsl 
    167       1.76       dsl 	if (fds[1] < 3) {
    168       1.76       dsl 		nfd = fcntl(fds[1], F_DUPFD, 3);
    169       1.76       dsl 		if (nfd != -1) {
    170       1.76       dsl 			close(fds[1]);
    171       1.76       dsl 			fds[1] = nfd;
    172       1.76       dsl 		}
    173       1.76       dsl 	}
    174       1.76       dsl 	return 0;
    175       1.76       dsl }
    176        1.1       cgd 
    177        1.1       cgd 
    178        1.1       cgd /*
    179      1.187   msaitoh  * The eval command.
    180        1.1       cgd  */
    181        1.1       cgd 
    182       1.16       cgd int
    183       1.68  christos evalcmd(int argc, char **argv)
    184        1.1       cgd {
    185      1.148       kre 	char *p;
    186      1.148       kre 	char *concat;
    187      1.148       kre 	char **ap;
    188      1.148       kre 
    189      1.148       kre 	if (argc > 1) {
    190      1.148       kre 		p = argv[1];
    191      1.148       kre 		if (argc > 2) {
    192      1.148       kre 			STARTSTACKSTR(concat);
    193      1.148       kre 			ap = argv + 2;
    194      1.148       kre 			for (;;) {
    195      1.148       kre 				while (*p)
    196      1.148       kre 					STPUTC(*p++, concat);
    197      1.148       kre 				if ((p = *ap++) == NULL)
    198      1.148       kre 					break;
    199      1.148       kre 				STPUTC(' ', concat);
    200      1.148       kre 			}
    201      1.148       kre 			STPUTC('\0', concat);
    202      1.148       kre 			p = grabstackstr(concat);
    203      1.148       kre 		}
    204      1.148       kre 		evalstring(p, builtin_flags & EV_TESTED);
    205      1.148       kre 	} else
    206      1.133       kre 		exitstatus = 0;
    207      1.148       kre 	return exitstatus;
    208        1.1       cgd }
    209        1.1       cgd 
    210        1.1       cgd 
    211        1.1       cgd /*
    212        1.1       cgd  * Execute a command or commands contained in a string.
    213        1.1       cgd  */
    214        1.1       cgd 
    215        1.1       cgd void
    216       1.68  christos evalstring(char *s, int flag)
    217       1.68  christos {
    218        1.1       cgd 	union node *n;
    219        1.1       cgd 	struct stackmark smark;
    220      1.159       kre 	int last;
    221      1.159       kre 	int any;
    222      1.159       kre 
    223      1.159       kre 	last = flag & EV_EXIT;
    224      1.159       kre 	flag &= ~EV_EXIT;
    225        1.1       cgd 
    226        1.1       cgd 	setstackmark(&smark);
    227      1.143       kre 	setinputstring(s, 1, line_number);
    228       1.64  christos 
    229      1.159       kre 	any = 0;	/* to determine if exitstatus will have been set */
    230        1.1       cgd 	while ((n = parsecmd(0)) != NEOF) {
    231      1.148       kre 		XTRACE(DBG_EVAL, ("evalstring: "), showtree(n));
    232      1.159       kre 		if (n && nflag == 0) {
    233      1.159       kre 			if (last && at_eof())
    234      1.159       kre 				evaltree(n, flag | EV_EXIT);
    235      1.159       kre 			else
    236      1.159       kre 				evaltree(n, flag);
    237      1.159       kre 			any = 1;
    238      1.163       kre 			if (evalskip)
    239      1.163       kre 				break;
    240      1.159       kre 		}
    241      1.160       kre 		rststackmark(&smark);
    242        1.1       cgd 	}
    243        1.1       cgd 	popfile();
    244        1.1       cgd 	popstackmark(&smark);
    245      1.159       kre 	if (!any)
    246      1.159       kre 		exitstatus = 0;
    247      1.159       kre 	if (last)
    248      1.159       kre 		exraise(EXEXIT);
    249        1.1       cgd }
    250        1.1       cgd 
    251        1.1       cgd 
    252        1.1       cgd 
    253        1.1       cgd /*
    254        1.1       cgd  * Evaluate a parse tree.  The value is left in the global variable
    255        1.1       cgd  * exitstatus.
    256        1.1       cgd  */
    257        1.1       cgd 
    258        1.1       cgd void
    259       1.68  christos evaltree(union node *n, int flags)
    260       1.17       cgd {
    261       1.90      tron 	bool do_etest;
    262      1.136       kre 	int sflags = flags & ~EV_EXIT;
    263      1.159       kre 	union node *next;
    264      1.159       kre 	struct stackmark smark;
    265       1.90      tron 
    266       1.90      tron 	do_etest = false;
    267      1.115  christos 	if (n == NULL || nflag) {
    268      1.148       kre 		VTRACE(DBG_EVAL, ("evaltree(%s) called\n",
    269      1.148       kre 		    n == NULL ? "NULL" : "-n"));
    270      1.115  christos 		if (nflag == 0)
    271      1.115  christos 			exitstatus = 0;
    272      1.159       kre 		goto out2;
    273        1.1       cgd 	}
    274      1.159       kre 
    275      1.159       kre 	setstackmark(&smark);
    276      1.159       kre 	do {
    277       1.35  christos #ifndef SMALL
    278      1.159       kre 		displayhist = 1; /* show history substitutions done with fc */
    279       1.10       cgd #endif
    280      1.159       kre 		next = NULL;
    281      1.159       kre 		CTRACE(DBG_EVAL, ("pid %d, evaltree(%p: %s(%d), %#x) called\n",
    282      1.159       kre 		    getpid(), n, NODETYPENAME(n->type), n->type, flags));
    283      1.181       kre 	/*
    284      1.168       kre 		if (n->type != NCMD && traps_invalid)
    285      1.168       kre 			free_traps();
    286      1.181       kre 	*/
    287      1.159       kre 		switch (n->type) {
    288      1.159       kre 		case NSEMI:
    289      1.159       kre 			evaltree(n->nbinary.ch1, sflags);
    290      1.159       kre 			if (nflag || evalskip)
    291      1.159       kre 				goto out1;
    292      1.159       kre 			next = n->nbinary.ch2;
    293      1.159       kre 			break;
    294      1.159       kre 		case NAND:
    295      1.159       kre 			evaltree(n->nbinary.ch1, EV_TESTED);
    296      1.159       kre 			if (nflag || evalskip || exitstatus != 0)
    297      1.159       kre 				goto out1;
    298      1.159       kre 			next = n->nbinary.ch2;
    299      1.159       kre 			break;
    300      1.159       kre 		case NOR:
    301      1.159       kre 			evaltree(n->nbinary.ch1, EV_TESTED);
    302      1.159       kre 			if (nflag || evalskip || exitstatus == 0)
    303      1.159       kre 				goto out1;
    304      1.159       kre 			next = n->nbinary.ch2;
    305      1.159       kre 			break;
    306      1.159       kre 		case NREDIR:
    307      1.181       kre 			if (traps_invalid)
    308      1.181       kre 				free_traps();
    309      1.159       kre 			evalredir(n, flags);
    310      1.159       kre 			break;
    311      1.159       kre 		case NSUBSHELL:
    312      1.159       kre 			evalsubshell(n, flags);
    313      1.159       kre 			do_etest = !(flags & EV_TESTED);
    314      1.159       kre 			break;
    315      1.159       kre 		case NBACKGND:
    316      1.181       kre 			if (traps_invalid)
    317      1.181       kre 				free_traps();
    318      1.159       kre 			evalsubshell(n, flags);
    319      1.159       kre 			break;
    320      1.159       kre 		case NIF: {
    321      1.181       kre 			if (traps_invalid)
    322      1.181       kre 				free_traps();
    323      1.159       kre 			evaltree(n->nif.test, EV_TESTED);
    324      1.159       kre 			if (nflag || evalskip)
    325      1.159       kre 				goto out1;
    326      1.159       kre 			if (exitstatus == 0)
    327      1.159       kre 				next = n->nif.ifpart;
    328      1.159       kre 			else if (n->nif.elsepart)
    329      1.159       kre 				next = n->nif.elsepart;
    330      1.159       kre 			else
    331      1.159       kre 				exitstatus = 0;
    332      1.159       kre 			break;
    333      1.151       kre 		}
    334      1.159       kre 		case NWHILE:
    335      1.159       kre 		case NUNTIL:
    336      1.181       kre 			if (traps_invalid)
    337      1.181       kre 				free_traps();
    338      1.159       kre 			evalloop(n, sflags);
    339      1.159       kre 			break;
    340      1.159       kre 		case NFOR:
    341      1.181       kre 			if (traps_invalid)
    342      1.181       kre 				free_traps();
    343      1.159       kre 			evalfor(n, sflags);
    344      1.159       kre 			break;
    345      1.159       kre 		case NCASE:
    346      1.181       kre 			if (traps_invalid)
    347      1.181       kre 				free_traps();
    348      1.159       kre 			evalcase(n, sflags);
    349      1.159       kre 			break;
    350      1.159       kre 		case NDEFUN:
    351      1.181       kre 			if (traps_invalid)
    352      1.181       kre 				free_traps();
    353      1.159       kre 			CTRACE(DBG_EVAL, ("Defining fn %s @%d%s\n",
    354      1.159       kre 			    n->narg.text, n->narg.lineno,
    355      1.159       kre 			    fnline1 ? " LINENO=1" : ""));
    356      1.159       kre 			defun(n->narg.text, n->narg.next, n->narg.lineno);
    357       1.29        pk 			exitstatus = 0;
    358      1.159       kre 			break;
    359      1.159       kre 		case NNOT:
    360      1.159       kre 			evaltree(n->nnot.com, EV_TESTED);
    361      1.159       kre 			exitstatus = !exitstatus;
    362      1.159       kre 			break;
    363      1.159       kre 		case NDNOT:
    364      1.159       kre 			evaltree(n->nnot.com, EV_TESTED);
    365      1.159       kre 			if (exitstatus != 0)
    366      1.159       kre 				exitstatus = 1;
    367      1.159       kre 			break;
    368      1.159       kre 		case NPIPE:
    369      1.181       kre 			if (traps_invalid)
    370      1.181       kre 				free_traps();
    371      1.159       kre 			evalpipe(n);
    372      1.159       kre 			do_etest = !(flags & EV_TESTED);
    373      1.159       kre 			break;
    374      1.159       kre 		case NCMD:
    375      1.159       kre 			evalcommand(n, flags, NULL);
    376      1.159       kre 			do_etest = !(flags & EV_TESTED);
    377      1.159       kre 			break;
    378      1.159       kre 		default:
    379      1.115  christos #ifdef NODETYPENAME
    380      1.159       kre 			out1fmt("Node type = %d(%s)\n",
    381      1.159       kre 				n->type, NODETYPENAME(n->type));
    382      1.115  christos #else
    383      1.159       kre 			out1fmt("Node type = %d\n", n->type);
    384      1.115  christos #endif
    385      1.159       kre 			flushout(&output);
    386      1.159       kre 			break;
    387      1.159       kre 		}
    388      1.159       kre 		n = next;
    389      1.160       kre 		rststackmark(&smark);
    390      1.159       kre 	} while(n != NULL);
    391      1.159       kre  out1:
    392      1.159       kre 	popstackmark(&smark);
    393      1.159       kre  out2:
    394        1.1       cgd 	if (pendingsigs)
    395        1.1       cgd 		dotrap();
    396      1.159       kre 	if (eflag && exitstatus != 0 && do_etest)
    397        1.1       cgd 		exitshell(exitstatus);
    398      1.159       kre 	if (flags & EV_EXIT)
    399      1.159       kre 		exraise(EXEXIT);
    400        1.1       cgd }
    401        1.1       cgd 
    402        1.1       cgd 
    403        1.1       cgd STATIC void
    404       1.68  christos evalloop(union node *n, int flags)
    405       1.22  christos {
    406        1.1       cgd 	int status;
    407        1.1       cgd 
    408        1.1       cgd 	loopnest++;
    409        1.1       cgd 	status = 0;
    410      1.114  christos 
    411      1.148       kre 	CTRACE(DBG_EVAL,  ("evalloop %s:", NODETYPENAME(n->type)));
    412      1.148       kre 	VXTRACE(DBG_EVAL, (" "), showtree(n->nbinary.ch1));
    413      1.148       kre 	VXTRACE(DBG_EVAL, ("evalloop    do: "), showtree(n->nbinary.ch2));
    414      1.148       kre 	VTRACE(DBG_EVAL,  ("evalloop  done\n"));
    415      1.148       kre 	CTRACE(DBG_EVAL,  ("\n"));
    416      1.114  christos 
    417        1.1       cgd 	for (;;) {
    418      1.158       kre 		evaltree(n->nbinary.ch1, EV_TESTED);
    419      1.115  christos 		if (nflag)
    420      1.115  christos 			break;
    421        1.1       cgd 		if (evalskip) {
    422      1.137       kre  skipping:		if (evalskip == SKIPCONT && --skipcount <= 0) {
    423      1.109  christos 				evalskip = SKIPNONE;
    424        1.1       cgd 				continue;
    425        1.1       cgd 			}
    426        1.1       cgd 			if (evalskip == SKIPBREAK && --skipcount <= 0)
    427      1.109  christos 				evalskip = SKIPNONE;
    428      1.175       kre 			if (evalskip == SKIPFUNC || evalskip == SKIPFILE)
    429      1.175       kre 				status = exitstatus;
    430        1.1       cgd 			break;
    431        1.1       cgd 		}
    432        1.1       cgd 		if (n->type == NWHILE) {
    433        1.1       cgd 			if (exitstatus != 0)
    434        1.1       cgd 				break;
    435        1.1       cgd 		} else {
    436        1.1       cgd 			if (exitstatus == 0)
    437        1.1       cgd 				break;
    438        1.1       cgd 		}
    439      1.158       kre 		evaltree(n->nbinary.ch2, flags & EV_TESTED);
    440        1.1       cgd 		status = exitstatus;
    441        1.1       cgd 		if (evalskip)
    442        1.1       cgd 			goto skipping;
    443        1.1       cgd 	}
    444        1.1       cgd 	loopnest--;
    445        1.1       cgd 	exitstatus = status;
    446        1.1       cgd }
    447        1.1       cgd 
    448        1.1       cgd 
    449        1.1       cgd 
    450        1.1       cgd STATIC void
    451       1.68  christos evalfor(union node *n, int flags)
    452       1.22  christos {
    453        1.1       cgd 	struct arglist arglist;
    454        1.1       cgd 	union node *argp;
    455        1.1       cgd 	struct strlist *sp;
    456        1.1       cgd 	struct stackmark smark;
    457      1.115  christos 	int status;
    458      1.115  christos 
    459      1.115  christos 	status = nflag ? exitstatus : 0;
    460        1.1       cgd 
    461        1.1       cgd 	setstackmark(&smark);
    462        1.1       cgd 	arglist.lastp = &arglist.list;
    463        1.1       cgd 	for (argp = n->nfor.args ; argp ; argp = argp->narg.next) {
    464       1.78       dsl 		expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
    465        1.1       cgd 		if (evalskip)
    466        1.1       cgd 			goto out;
    467        1.1       cgd 	}
    468        1.1       cgd 	*arglist.lastp = NULL;
    469        1.1       cgd 
    470        1.1       cgd 	loopnest++;
    471        1.1       cgd 	for (sp = arglist.list ; sp ; sp = sp->next) {
    472      1.184       kre 		line_number = n->nfor.lineno;
    473      1.131       kre 		if (xflag) {
    474      1.153       kre 			outxstr(expandstr(ps4val(), line_number));
    475      1.153       kre 			outxstr("for ");
    476      1.153       kre 			outxstr(n->nfor.var);
    477      1.153       kre 			outxc('=');
    478      1.153       kre 			outxshstr(sp->text);
    479      1.153       kre 			outxc('\n');
    480      1.153       kre 			flushout(outx);
    481      1.131       kre 		}
    482      1.131       kre 
    483        1.1       cgd 		setvar(n->nfor.var, sp->text, 0);
    484      1.158       kre 		evaltree(n->nfor.body, flags & EV_TESTED);
    485       1.68  christos 		status = exitstatus;
    486      1.115  christos 		if (nflag)
    487      1.115  christos 			break;
    488        1.1       cgd 		if (evalskip) {
    489        1.1       cgd 			if (evalskip == SKIPCONT && --skipcount <= 0) {
    490      1.109  christos 				evalskip = SKIPNONE;
    491        1.1       cgd 				continue;
    492        1.1       cgd 			}
    493        1.1       cgd 			if (evalskip == SKIPBREAK && --skipcount <= 0)
    494      1.109  christos 				evalskip = SKIPNONE;
    495        1.1       cgd 			break;
    496        1.1       cgd 		}
    497        1.1       cgd 	}
    498        1.1       cgd 	loopnest--;
    499       1.68  christos 	exitstatus = status;
    500      1.148       kre  out:
    501        1.1       cgd 	popstackmark(&smark);
    502        1.1       cgd }
    503        1.1       cgd 
    504        1.1       cgd 
    505        1.1       cgd 
    506        1.1       cgd STATIC void
    507       1.68  christos evalcase(union node *n, int flags)
    508       1.16       cgd {
    509      1.134       kre 	union node *cp, *ncp;
    510        1.1       cgd 	union node *patp;
    511        1.1       cgd 	struct arglist arglist;
    512        1.1       cgd 	struct stackmark smark;
    513       1.68  christos 	int status = 0;
    514        1.1       cgd 
    515        1.1       cgd 	setstackmark(&smark);
    516        1.1       cgd 	arglist.lastp = &arglist.list;
    517      1.143       kre 	line_number = n->ncase.lineno;
    518        1.7       jtc 	expandarg(n->ncase.expr, &arglist, EXP_TILDE);
    519      1.134       kre 	for (cp = n->ncase.cases; cp && evalskip == 0; cp = cp->nclist.next) {
    520      1.134       kre 		for (patp = cp->nclist.pattern; patp; patp = patp->narg.next) {
    521      1.143       kre 			line_number = patp->narg.lineno;
    522        1.1       cgd 			if (casematch(patp, arglist.list->text)) {
    523      1.134       kre 				while (cp != NULL && evalskip == 0 &&
    524      1.134       kre 				    nflag == 0) {
    525      1.134       kre 					if (cp->type == NCLISTCONT)
    526      1.134       kre 						ncp = cp->nclist.next;
    527      1.134       kre 					else
    528      1.134       kre 						ncp = NULL;
    529      1.143       kre 					line_number = cp->nclist.lineno;
    530      1.158       kre 					evaltree(cp->nclist.body, flags);
    531       1.68  christos 					status = exitstatus;
    532      1.134       kre 					cp = ncp;
    533        1.1       cgd 				}
    534        1.1       cgd 				goto out;
    535        1.1       cgd 			}
    536        1.1       cgd 		}
    537        1.1       cgd 	}
    538      1.134       kre  out:
    539       1.68  christos 	exitstatus = status;
    540        1.1       cgd 	popstackmark(&smark);
    541        1.1       cgd }
    542        1.1       cgd 
    543        1.1       cgd 
    544        1.1       cgd 
    545        1.1       cgd /*
    546        1.1       cgd  * Kick off a subshell to evaluate a tree.
    547        1.1       cgd  */
    548        1.1       cgd 
    549        1.1       cgd STATIC void
    550       1.68  christos evalsubshell(union node *n, int flags)
    551       1.16       cgd {
    552      1.159       kre 	struct job *jp= NULL;
    553        1.1       cgd 	int backgnd = (n->type == NBACKGND);
    554        1.1       cgd 
    555        1.1       cgd 	expredir(n->nredir.redirect);
    556      1.151       kre 	if (xflag && n->nredir.redirect) {
    557      1.151       kre 		union node *rn;
    558      1.151       kre 
    559      1.153       kre 		outxstr(expandstr(ps4val(), line_number));
    560      1.153       kre 		outxstr("using redirections:");
    561      1.151       kre 		for (rn = n->nredir.redirect; rn; rn = rn->nfile.next)
    562      1.153       kre 			(void) outredir(outx, rn, ' ');
    563      1.159       kre 		outxstr(" do subshell ("/*)*/);
    564      1.159       kre 		if (backgnd)
    565      1.159       kre 			outxstr(/*(*/") &");
    566      1.159       kre 		outxc('\n');
    567      1.153       kre 		flushout(outx);
    568      1.151       kre 	}
    569      1.172       kre 	INTOFF;
    570      1.182       kre 	if ((!backgnd && flags & EV_EXIT && !have_traps() && !anyjobs()) ||
    571      1.159       kre 	    forkshell(jp = makejob(n, 1), n, backgnd?FORK_BG:FORK_FG) == 0) {
    572        1.1       cgd 		if (backgnd)
    573        1.1       cgd 			flags &=~ EV_TESTED;
    574      1.177       kre 		INTON;
    575      1.119  christos 		redirect(n->nredir.redirect, REDIR_KEEP);
    576      1.159       kre 		evaltree(n->nredir.n, flags | EV_EXIT);   /* never returns */
    577      1.172       kre 	} else if (backgnd)
    578      1.172       kre 		exitstatus = 0;
    579      1.172       kre 	else
    580      1.159       kre 		exitstatus = waitforjob(jp);
    581      1.172       kre 	INTON;
    582      1.159       kre 
    583      1.151       kre 	if (!backgnd && xflag && n->nredir.redirect) {
    584      1.153       kre 		outxstr(expandstr(ps4val(), line_number));
    585      1.159       kre 		outxstr(/*(*/") done subshell\n");
    586      1.153       kre 		flushout(outx);
    587      1.151       kre 	}
    588        1.1       cgd }
    589        1.1       cgd 
    590        1.1       cgd 
    591        1.1       cgd 
    592        1.1       cgd /*
    593        1.1       cgd  * Compute the names of the files in a redirection list.
    594        1.1       cgd  */
    595        1.1       cgd 
    596        1.1       cgd STATIC void
    597       1.68  christos expredir(union node *n)
    598       1.22  christos {
    599       1.34       tls 	union node *redir;
    600        1.1       cgd 
    601        1.1       cgd 	for (redir = n ; redir ; redir = redir->nfile.next) {
    602       1.14       jtc 		struct arglist fn;
    603      1.120  christos 
    604       1.14       jtc 		fn.lastp = &fn.list;
    605       1.14       jtc 		switch (redir->type) {
    606       1.45  christos 		case NFROMTO:
    607       1.14       jtc 		case NFROM:
    608       1.14       jtc 		case NTO:
    609       1.59  christos 		case NCLOBBER:
    610       1.14       jtc 		case NAPPEND:
    611        1.7       jtc 			expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR);
    612        1.1       cgd 			redir->nfile.expfname = fn.list->text;
    613       1.14       jtc 			break;
    614       1.14       jtc 		case NFROMFD:
    615       1.14       jtc 		case NTOFD:
    616       1.14       jtc 			if (redir->ndup.vname) {
    617      1.149       kre 				expandarg(redir->ndup.vname, &fn, EXP_TILDE | EXP_REDIR);
    618       1.14       jtc 				fixredir(redir, fn.list->text, 1);
    619       1.14       jtc 			}
    620       1.14       jtc 			break;
    621      1.186       kre 		case NHERE:
    622      1.186       kre 			redir->nhere.text = redir->nhere.doc->narg.text;
    623      1.186       kre 			break;
    624      1.186       kre 		case NXHERE:
    625      1.186       kre 			redir->nhere.text = expandhere(redir->nhere.doc);
    626      1.186       kre 			break;
    627        1.1       cgd 		}
    628        1.1       cgd 	}
    629        1.1       cgd }
    630        1.1       cgd 
    631      1.159       kre /*
    632      1.159       kre  * Perform redirections for a compound command, and then do it (and restore)
    633      1.159       kre  */
    634      1.159       kre STATIC void
    635      1.159       kre evalredir(union node *n, int flags)
    636      1.159       kre {
    637      1.159       kre 	struct jmploc jmploc;
    638      1.159       kre 	struct jmploc * const savehandler = handler;
    639      1.159       kre 	volatile int in_redirect = 1;
    640      1.159       kre 	const char * volatile PS4 = NULL;
    641      1.159       kre 
    642      1.159       kre 	expredir(n->nredir.redirect);
    643      1.159       kre 
    644      1.159       kre 	if (xflag && n->nredir.redirect) {
    645      1.159       kre 		union node *rn;
    646      1.159       kre 
    647      1.159       kre 		outxstr(PS4 = expandstr(ps4val(), line_number));
    648      1.159       kre 		outxstr("using redirections:");
    649      1.159       kre 		for (rn = n->nredir.redirect; rn != NULL; rn = rn->nfile.next)
    650      1.159       kre 			(void) outredir(outx, rn, ' ');
    651      1.159       kre 		outxstr(" do {\n");	/* } */
    652      1.159       kre 		flushout(outx);
    653      1.159       kre 	}
    654      1.159       kre 
    655      1.159       kre 	if (setjmp(jmploc.loc)) {
    656      1.159       kre 		int e;
    657      1.159       kre 
    658      1.159       kre 		handler = savehandler;
    659      1.159       kre 		e = exception;
    660      1.159       kre 		popredir();
    661      1.162       kre 		if (PS4 != NULL) {
    662      1.159       kre 			outxstr(PS4);
    663      1.159       kre 			/* { */ outxstr("} failed\n");
    664      1.159       kre 			flushout(outx);
    665      1.159       kre 		}
    666      1.159       kre 		if (e == EXERROR || e == EXEXEC) {
    667      1.159       kre 			if (in_redirect) {
    668      1.159       kre 				exitstatus = 2;
    669      1.159       kre 				return;
    670      1.159       kre 			}
    671      1.159       kre 		}
    672      1.159       kre 		longjmp(handler->loc, 1);
    673      1.159       kre 	} else {
    674      1.159       kre 		INTOFF;
    675      1.159       kre 		handler = &jmploc;
    676      1.159       kre 		redirect(n->nredir.redirect, REDIR_PUSH | REDIR_KEEP);
    677      1.159       kre 		in_redirect = 0;
    678      1.159       kre 		INTON;
    679      1.159       kre 		evaltree(n->nredir.n, flags);
    680      1.159       kre 	}
    681      1.159       kre 	INTOFF;
    682      1.159       kre 	handler = savehandler;
    683      1.159       kre 	popredir();
    684      1.159       kre 	INTON;
    685      1.159       kre 
    686      1.162       kre 	if (PS4 != NULL) {
    687      1.159       kre 		outxstr(PS4);
    688      1.159       kre 		/* { */ outxstr("} done\n");
    689      1.159       kre 		flushout(outx);
    690      1.159       kre 	}
    691      1.159       kre }
    692        1.1       cgd 
    693        1.1       cgd 
    694        1.1       cgd /*
    695        1.1       cgd  * Evaluate a pipeline.  All the processes in the pipeline are children
    696        1.1       cgd  * of the process creating the pipeline.  (This differs from some versions
    697        1.1       cgd  * of the shell, which make the last process in a pipeline the parent
    698        1.1       cgd  * of all the rest.)
    699        1.1       cgd  */
    700        1.1       cgd 
    701        1.1       cgd STATIC void
    702       1.68  christos evalpipe(union node *n)
    703       1.22  christos {
    704        1.1       cgd 	struct job *jp;
    705        1.1       cgd 	struct nodelist *lp;
    706        1.1       cgd 	int pipelen;
    707        1.1       cgd 	int prevfd;
    708        1.1       cgd 	int pip[2];
    709        1.1       cgd 
    710      1.148       kre 	CTRACE(DBG_EVAL, ("evalpipe(%p) called\n", n));
    711        1.1       cgd 	pipelen = 0;
    712        1.1       cgd 	for (lp = n->npipe.cmdlist ; lp ; lp = lp->next)
    713        1.1       cgd 		pipelen++;
    714        1.1       cgd 	INTOFF;
    715        1.1       cgd 	jp = makejob(n, pipelen);
    716        1.1       cgd 	prevfd = -1;
    717        1.1       cgd 	for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) {
    718        1.1       cgd 		prehash(lp->n);
    719        1.1       cgd 		pip[1] = -1;
    720        1.1       cgd 		if (lp->next) {
    721       1.76       dsl 			if (sh_pipe(pip) < 0) {
    722       1.87  christos 				if (prevfd >= 0)
    723       1.87  christos 					close(prevfd);
    724      1.159       kre 				error("Pipe call failed: %s", strerror(errno));
    725        1.1       cgd 			}
    726        1.1       cgd 		}
    727      1.159       kre 		if (forkshell(jp, lp->n,
    728      1.159       kre 		    n->npipe.backgnd ? FORK_BG : FORK_FG) == 0) {
    729        1.1       cgd 			INTON;
    730      1.120  christos 			if (prevfd > 0)
    731      1.120  christos 				movefd(prevfd, 0);
    732        1.1       cgd 			if (pip[1] >= 0) {
    733        1.1       cgd 				close(pip[0]);
    734      1.120  christos 				movefd(pip[1], 1);
    735        1.1       cgd 			}
    736       1.65  christos 			evaltree(lp->n, EV_EXIT);
    737        1.1       cgd 		}
    738        1.1       cgd 		if (prevfd >= 0)
    739        1.1       cgd 			close(prevfd);
    740        1.1       cgd 		prevfd = pip[0];
    741        1.1       cgd 		close(pip[1]);
    742        1.1       cgd 	}
    743        1.1       cgd 	if (n->npipe.backgnd == 0) {
    744        1.1       cgd 		exitstatus = waitforjob(jp);
    745      1.148       kre 		CTRACE(DBG_EVAL, ("evalpipe:  job done exit status %d\n",
    746      1.148       kre 		    exitstatus));
    747      1.115  christos 	} else
    748      1.115  christos 		exitstatus = 0;
    749       1.60   mycroft 	INTON;
    750        1.1       cgd }
    751        1.1       cgd 
    752        1.1       cgd 
    753        1.1       cgd 
    754        1.1       cgd /*
    755        1.1       cgd  * Execute a command inside back quotes.  If it's a builtin command, we
    756        1.1       cgd  * want to save its output in a block obtained from malloc.  Otherwise
    757        1.1       cgd  * we fork off a subprocess and get the output of the command via a pipe.
    758        1.1       cgd  * Should be called with interrupts off.
    759        1.1       cgd  */
    760        1.1       cgd 
    761        1.1       cgd void
    762       1.68  christos evalbackcmd(union node *n, struct backcmd *result)
    763       1.22  christos {
    764        1.1       cgd 	int pip[2];
    765        1.1       cgd 	struct job *jp;
    766      1.159       kre 	struct stackmark smark;		/* unnecessary (because we fork) */
    767        1.1       cgd 
    768        1.1       cgd 	result->fd = -1;
    769        1.1       cgd 	result->buf = NULL;
    770        1.1       cgd 	result->nleft = 0;
    771        1.1       cgd 	result->jp = NULL;
    772      1.159       kre 
    773      1.159       kre 	if (nflag || n == NULL)
    774        1.7       jtc 		goto out;
    775      1.159       kre 
    776      1.159       kre 	setstackmark(&smark);
    777      1.159       kre 
    778       1.46  christos #ifdef notyet
    779       1.46  christos 	/*
    780       1.46  christos 	 * For now we disable executing builtins in the same
    781       1.46  christos 	 * context as the shell, because we are not keeping
    782       1.46  christos 	 * enough state to recover from changes that are
    783       1.46  christos 	 * supposed only to affect subshells. eg. echo "`cd /`"
    784       1.46  christos 	 */
    785        1.7       jtc 	if (n->type == NCMD) {
    786      1.159       kre 		exitstatus = oexitstatus;	/* XXX o... no longer exists */
    787       1.65  christos 		evalcommand(n, EV_BACKCMD, result);
    788       1.46  christos 	} else
    789       1.46  christos #endif
    790       1.46  christos 	{
    791       1.63   mycroft 		INTOFF;
    792       1.76       dsl 		if (sh_pipe(pip) < 0)
    793        1.1       cgd 			error("Pipe call failed");
    794        1.1       cgd 		jp = makejob(n, 1);
    795       1.65  christos 		if (forkshell(jp, n, FORK_NOJOB) == 0) {
    796        1.1       cgd 			FORCEINTON;
    797        1.1       cgd 			close(pip[0]);
    798      1.120  christos 			movefd(pip[1], 1);
    799       1.65  christos 			evaltree(n, EV_EXIT);
    800       1.68  christos 			/* NOTREACHED */
    801        1.1       cgd 		}
    802        1.1       cgd 		close(pip[1]);
    803        1.1       cgd 		result->fd = pip[0];
    804        1.1       cgd 		result->jp = jp;
    805       1.63   mycroft 		INTON;
    806        1.1       cgd 	}
    807      1.159       kre 	popstackmark(&smark);
    808      1.148       kre  out:
    809      1.148       kre 	CTRACE(DBG_EVAL, ("evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n",
    810        1.1       cgd 		result->fd, result->buf, result->nleft, result->jp));
    811        1.1       cgd }
    812        1.1       cgd 
    813      1.156       kre const char *
    814       1.70       dsl syspath(void)
    815       1.70       dsl {
    816       1.70       dsl 	static char *sys_path = NULL;
    817       1.70       dsl 	static int mib[] = {CTL_USER, USER_CS_PATH};
    818       1.80  christos 	static char def_path[] = "PATH=/usr/bin:/bin:/usr/sbin:/sbin";
    819       1.72       agc 	size_t len;
    820       1.70       dsl 
    821       1.70       dsl 	if (sys_path == NULL) {
    822       1.70       dsl 		if (sysctl(mib, 2, 0, &len, 0, 0) != -1 &&
    823       1.70       dsl 		    (sys_path = ckmalloc(len + 5)) != NULL &&
    824       1.70       dsl 		    sysctl(mib, 2, sys_path + 5, &len, 0, 0) != -1) {
    825       1.70       dsl 			memcpy(sys_path, "PATH=", 5);
    826       1.70       dsl 		} else {
    827       1.70       dsl 			ckfree(sys_path);
    828       1.70       dsl 			/* something to keep things happy */
    829       1.80  christos 			sys_path = def_path;
    830       1.70       dsl 		}
    831       1.70       dsl 	}
    832       1.70       dsl 	return sys_path;
    833       1.70       dsl }
    834       1.70       dsl 
    835       1.70       dsl static int
    836       1.70       dsl parse_command_args(int argc, char **argv, int *use_syspath)
    837       1.70       dsl {
    838       1.70       dsl 	int sv_argc = argc;
    839       1.70       dsl 	char *cp, c;
    840       1.70       dsl 
    841       1.70       dsl 	*use_syspath = 0;
    842       1.70       dsl 
    843       1.70       dsl 	for (;;) {
    844       1.70       dsl 		argv++;
    845       1.70       dsl 		if (--argc == 0)
    846       1.70       dsl 			break;
    847       1.70       dsl 		cp = *argv;
    848       1.70       dsl 		if (*cp++ != '-')
    849       1.70       dsl 			break;
    850       1.70       dsl 		if (*cp == '-' && cp[1] == 0) {
    851       1.70       dsl 			argv++;
    852       1.70       dsl 			argc--;
    853       1.70       dsl 			break;
    854       1.70       dsl 		}
    855       1.70       dsl 		while ((c = *cp++)) {
    856       1.70       dsl 			switch (c) {
    857       1.70       dsl 			case 'p':
    858       1.70       dsl 				*use_syspath = 1;
    859       1.70       dsl 				break;
    860       1.70       dsl 			default:
    861       1.70       dsl 				/* run 'typecmd' for other options */
    862       1.70       dsl 				return 0;
    863       1.70       dsl 			}
    864       1.70       dsl 		}
    865       1.70       dsl 	}
    866       1.70       dsl 	return sv_argc - argc;
    867       1.70       dsl }
    868        1.1       cgd 
    869       1.61  christos int vforked = 0;
    870        1.1       cgd 
    871        1.1       cgd /*
    872        1.1       cgd  * Execute a simple command.
    873        1.1       cgd  */
    874        1.1       cgd 
    875        1.1       cgd STATIC void
    876       1.88  christos evalcommand(union node *cmd, int flgs, struct backcmd *backcmd)
    877       1.16       cgd {
    878        1.1       cgd 	struct stackmark smark;
    879        1.1       cgd 	union node *argp;
    880        1.1       cgd 	struct arglist arglist;
    881        1.1       cgd 	struct arglist varlist;
    882       1.88  christos 	volatile int flags = flgs;
    883       1.88  christos 	char ** volatile argv;
    884       1.88  christos 	volatile int argc;
    885        1.1       cgd 	char **envp;
    886        1.1       cgd 	int varflag;
    887        1.1       cgd 	struct strlist *sp;
    888       1.88  christos 	volatile int mode;
    889        1.1       cgd 	int pip[2];
    890        1.1       cgd 	struct cmdentry cmdentry;
    891       1.88  christos 	struct job * volatile jp;
    892        1.1       cgd 	struct jmploc jmploc;
    893       1.85  christos 	struct jmploc *volatile savehandler = NULL;
    894       1.89      matt 	const char *volatile savecmdname;
    895        1.1       cgd 	volatile struct shparam saveparam;
    896        1.1       cgd 	struct localvar *volatile savelocalvars;
    897      1.169       kre 	struct parsefile *volatile savetopfile;
    898        1.1       cgd 	volatile int e;
    899       1.88  christos 	char * volatile lastarg;
    900       1.88  christos 	const char * volatile path = pathval();
    901       1.82     lukem 	volatile int temp_path;
    902      1.143       kre 	const int savefuncline = funclinebase;
    903      1.143       kre 	const int savefuncabs = funclineabs;
    904      1.164       kre 	volatile int cmd_flags = 0;
    905        1.1       cgd 
    906       1.61  christos 	vforked = 0;
    907        1.1       cgd 	/* First expand the arguments. */
    908      1.153       kre 	CTRACE(DBG_EVAL, ("evalcommand(%p, %d) called [%s]\n", cmd, flags,
    909      1.153       kre 	    cmd->ncmd.args ? cmd->ncmd.args->narg.text : ""));
    910        1.1       cgd 	setstackmark(&smark);
    911       1.68  christos 	back_exitstatus = 0;
    912       1.68  christos 
    913      1.151       kre 	line_number = cmd->ncmd.lineno;
    914      1.142       kre 
    915        1.1       cgd 	arglist.lastp = &arglist.list;
    916        1.1       cgd 	varflag = 1;
    917       1.78       dsl 	/* Expand arguments, ignoring the initial 'name=value' ones */
    918        1.1       cgd 	for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) {
    919      1.166       kre 		if (varflag && isassignment(argp->narg.text))
    920      1.166       kre 			continue;
    921      1.166       kre 		varflag = 0;
    922      1.143       kre 		line_number = argp->narg.lineno;
    923        1.7       jtc 		expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
    924        1.1       cgd 	}
    925        1.1       cgd 	*arglist.lastp = NULL;
    926       1.68  christos 
    927       1.68  christos 	expredir(cmd->ncmd.redirect);
    928       1.68  christos 
    929       1.78       dsl 	/* Now do the initial 'name=value' ones we skipped above */
    930       1.68  christos 	varlist.lastp = &varlist.list;
    931       1.68  christos 	for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) {
    932      1.143       kre 		line_number = argp->narg.lineno;
    933      1.166       kre 		if (!isassignment(argp->narg.text))
    934       1.68  christos 			break;
    935  1.188.2.1    martin 		/* EXP_CASE handles CTL* chars in expansions properly */
    936  1.188.2.1    martin 		expandarg(argp, &varlist, EXP_VARTILDE | EXP_CASE);
    937       1.68  christos 	}
    938        1.1       cgd 	*varlist.lastp = NULL;
    939       1.68  christos 
    940        1.1       cgd 	argc = 0;
    941        1.1       cgd 	for (sp = arglist.list ; sp ; sp = sp->next)
    942        1.1       cgd 		argc++;
    943        1.1       cgd 	argv = stalloc(sizeof (char *) * (argc + 1));
    944        1.7       jtc 
    945        1.7       jtc 	for (sp = arglist.list ; sp ; sp = sp->next) {
    946      1.148       kre 		VTRACE(DBG_EVAL, ("evalcommand arg: %s\n", sp->text));
    947        1.1       cgd 		*argv++ = sp->text;
    948        1.7       jtc 	}
    949        1.1       cgd 	*argv = NULL;
    950        1.1       cgd 	lastarg = NULL;
    951        1.1       cgd 	if (iflag && funcnest == 0 && argc > 0)
    952        1.1       cgd 		lastarg = argv[-1];
    953        1.1       cgd 	argv -= argc;
    954        1.1       cgd 
    955        1.1       cgd 	/* Print the command if xflag is set. */
    956        1.1       cgd 	if (xflag) {
    957       1.70       dsl 		char sep = 0;
    958      1.151       kre 		union node *rn;
    959      1.151       kre 
    960      1.153       kre 		outxstr(expandstr(ps4val(), line_number));
    961        1.1       cgd 		for (sp = varlist.list ; sp ; sp = sp->next) {
    962      1.116  christos 			char *p;
    963      1.116  christos 
    964       1.70       dsl 			if (sep != 0)
    965      1.153       kre 				outxc(sep);
    966      1.116  christos 
    967      1.116  christos 			/*
    968      1.116  christos 			 * The "var=" part should not be quoted, regardless
    969      1.116  christos 			 * of the value, or it would not represent an
    970      1.116  christos 			 * assignment, but rather a command
    971      1.116  christos 			 */
    972      1.116  christos 			p = strchr(sp->text, '=');
    973      1.116  christos 			if (p != NULL) {
    974      1.116  christos 				*p = '\0';	/*XXX*/
    975      1.153       kre 				outxshstr(sp->text);
    976      1.153       kre 				outxc('=');
    977      1.116  christos 				*p++ = '=';	/*XXX*/
    978      1.116  christos 			} else
    979      1.116  christos 				p = sp->text;
    980      1.153       kre 			outxshstr(p);
    981       1.70       dsl 			sep = ' ';
    982        1.1       cgd 		}
    983        1.1       cgd 		for (sp = arglist.list ; sp ; sp = sp->next) {
    984       1.70       dsl 			if (sep != 0)
    985      1.153       kre 				outxc(sep);
    986      1.153       kre 			outxshstr(sp->text);
    987       1.70       dsl 			sep = ' ';
    988        1.1       cgd 		}
    989      1.151       kre 		for (rn = cmd->ncmd.redirect; rn; rn = rn->nfile.next)
    990      1.153       kre 			if (outredir(outx, rn, sep))
    991      1.151       kre 				sep = ' ';
    992      1.153       kre 		outxc('\n');
    993      1.153       kre 		flushout(outx);
    994        1.1       cgd 	}
    995        1.1       cgd 
    996        1.1       cgd 	/* Now locate the command. */
    997        1.1       cgd 	if (argc == 0) {
    998      1.164       kre 		/*
    999      1.164       kre 		 * the empty command begins as a normal builtin, and
   1000      1.164       kre 		 * remains that way while redirects are processed, then
   1001      1.164       kre 		 * will become special before we get to doing the
   1002      1.164       kre 		 * var assigns.
   1003      1.164       kre 		 */
   1004      1.164       kre 		cmdentry.cmdtype = CMDBUILTIN;
   1005       1.68  christos 		cmdentry.u.bltin = bltincmd;
   1006      1.174       kre 		VTRACE(DBG_CMDS, ("No command name, assume \"comamnd\"\n"));
   1007        1.1       cgd 	} else {
   1008       1.26  christos 		static const char PATH[] = "PATH=";
   1009       1.26  christos 
   1010       1.26  christos 		/*
   1011       1.26  christos 		 * Modify the command lookup path, if a PATH= assignment
   1012       1.26  christos 		 * is present
   1013       1.26  christos 		 */
   1014       1.70       dsl 		for (sp = varlist.list; sp; sp = sp->next)
   1015       1.26  christos 			if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0)
   1016       1.26  christos 				path = sp->text + sizeof(PATH) - 1;
   1017       1.26  christos 
   1018       1.70       dsl 		do {
   1019       1.70       dsl 			int argsused, use_syspath;
   1020      1.143       kre 
   1021       1.70       dsl 			find_command(argv[0], &cmdentry, cmd_flags, path);
   1022      1.174       kre 			VTRACE(DBG_CMDS, ("Command %s type %d\n", argv[0],
   1023      1.174       kre 			    cmdentry.cmdtype));
   1024      1.157       kre #if 0
   1025      1.157       kre 			/*
   1026      1.157       kre 			 * This short circuits all of the processing that
   1027      1.157       kre 			 * should be done (including processing the
   1028      1.157       kre 			 * redirects), so just don't ...
   1029      1.157       kre 			 *
   1030      1.157       kre 			 * (eventually this whole #if'd block will vanish)
   1031      1.157       kre 			 */
   1032       1.70       dsl 			if (cmdentry.cmdtype == CMDUNKNOWN) {
   1033       1.68  christos 				exitstatus = 127;
   1034       1.68  christos 				flushout(&errout);
   1035       1.70       dsl 				goto out;
   1036        1.1       cgd 			}
   1037      1.157       kre #endif
   1038       1.70       dsl 
   1039       1.70       dsl 			/* implement the 'command' builtin here */
   1040       1.70       dsl 			if (cmdentry.cmdtype != CMDBUILTIN ||
   1041       1.70       dsl 			    cmdentry.u.bltin != bltincmd)
   1042       1.70       dsl 				break;
   1043      1.174       kre 			VTRACE(DBG_CMDS, ("Command \"command\"\n"));
   1044       1.70       dsl 			cmd_flags |= DO_NOFUNC;
   1045       1.70       dsl 			argsused = parse_command_args(argc, argv, &use_syspath);
   1046       1.70       dsl 			if (argsused == 0) {
   1047      1.154       kre 				/* use 'type' builtin to display info */
   1048      1.174       kre 				VTRACE(DBG_CMDS,
   1049      1.174       kre 				    ("Command \"command\" -> \"type\"\n"));
   1050       1.70       dsl 				cmdentry.u.bltin = typecmd;
   1051       1.70       dsl 				break;
   1052       1.70       dsl 			}
   1053       1.70       dsl 			argc -= argsused;
   1054       1.70       dsl 			argv += argsused;
   1055       1.70       dsl 			if (use_syspath)
   1056       1.70       dsl 				path = syspath() + 5;
   1057       1.70       dsl 		} while (argc != 0);
   1058       1.70       dsl 		if (cmdentry.cmdtype == CMDSPLBLTIN && cmd_flags & DO_NOFUNC)
   1059       1.70       dsl 			/* posix mandates that 'command <splbltin>' act as if
   1060       1.70       dsl 			   <splbltin> was a normal builtin */
   1061       1.70       dsl 			cmdentry.cmdtype = CMDBUILTIN;
   1062        1.1       cgd 	}
   1063        1.1       cgd 
   1064      1.170       kre 	/*
   1065      1.170       kre 	 * When traps are invalid, we permit the following:
   1066      1.170       kre 	 *	trap
   1067      1.170       kre 	 *	command trap
   1068      1.170       kre 	 *	eval trap
   1069      1.170       kre 	 *	command eval trap
   1070      1.170       kre 	 *	eval command trap
   1071      1.170       kre 	 * without zapping the traps completely, in all other cases we do.
   1072      1.181       kre 	 * Function calls also do not zap the traps (but commands they execute
   1073      1.181       kre 	 * probably will) - this allows a function like
   1074      1.181       kre 	 *	trapstate() { trap -p; }
   1075      1.181       kre 	 * called as save_traps=$(trapstate).
   1076      1.170       kre 	 *
   1077      1.170       kre 	 * The test here permits eval "anything" but when evalstring() comes
   1078      1.170       kre 	 * back here again, the "anything" will be validated.
   1079      1.170       kre 	 * This means we can actually do:
   1080      1.170       kre 	 *	eval eval eval command eval eval command trap
   1081      1.170       kre 	 * as long as we end up with just "trap"
   1082      1.170       kre 	 *
   1083      1.170       kre 	 * We permit "command" by allowing CMDBUILTIN as well as CMDSPLBLTIN
   1084      1.170       kre 	 *
   1085      1.170       kre 	 * trapcmd() takes care of doing free_traps() if it is needed there.
   1086      1.170       kre 	 */
   1087      1.170       kre 	if (traps_invalid &&
   1088      1.181       kre 	    cmdentry.cmdtype != CMDFUNCTION &&
   1089      1.170       kre 	    ((cmdentry.cmdtype!=CMDSPLBLTIN && cmdentry.cmdtype!=CMDBUILTIN) ||
   1090      1.170       kre 	     (cmdentry.u.bltin != trapcmd && cmdentry.u.bltin != evalcmd)))
   1091      1.168       kre 		free_traps();
   1092      1.168       kre 
   1093        1.1       cgd 	/* Fork off a child process if necessary. */
   1094      1.176       kre 	if (cmd->ncmd.backgnd
   1095      1.176       kre 	  || ((cmdentry.cmdtype == CMDNORMAL || cmdentry.cmdtype == CMDUNKNOWN)
   1096      1.176       kre 	     && (have_traps() || (flags & EV_EXIT) == 0))
   1097      1.176       kre #ifdef notyet			/* EV_BACKCMD is never set currently */
   1098      1.176       kre 			/* this will need more work if/when it gets used */
   1099      1.176       kre 	  || ((flags & EV_BACKCMD) != 0
   1100      1.176       kre 	     && (cmdentry.cmdtype != CMDBUILTIN
   1101      1.176       kre 	         && cmdentry.cmdtype != CMDSPLBLTIN)
   1102      1.176       kre 	       || cmdentry.u.bltin == dotcmd
   1103      1.176       kre 	       || cmdentry.u.bltin == evalcmd)
   1104      1.176       kre #endif
   1105      1.176       kre 	 ) {
   1106       1.62  christos 		INTOFF;
   1107        1.1       cgd 		jp = makejob(cmd, 1);
   1108        1.1       cgd 		mode = cmd->ncmd.backgnd;
   1109        1.1       cgd 		if (flags & EV_BACKCMD) {
   1110        1.1       cgd 			mode = FORK_NOJOB;
   1111       1.76       dsl 			if (sh_pipe(pip) < 0)
   1112        1.1       cgd 				error("Pipe call failed");
   1113        1.1       cgd 		}
   1114       1.61  christos #ifdef DO_SHAREDVFORK
   1115       1.61  christos 		/* It is essential that if DO_SHAREDVFORK is defined that the
   1116       1.61  christos 		 * child's address space is actually shared with the parent as
   1117       1.61  christos 		 * we rely on this.
   1118       1.61  christos 		 */
   1119      1.177       kre 		if (usefork == 0 && cmdentry.cmdtype == CMDNORMAL &&
   1120      1.177       kre 		    (!cmd->ncmd.backgnd || cmd->ncmd.redirect == NULL)) {
   1121       1.61  christos 			pid_t	pid;
   1122      1.108  christos 			int serrno;
   1123       1.61  christos 
   1124       1.61  christos 			savelocalvars = localvars;
   1125       1.61  christos 			localvars = NULL;
   1126       1.61  christos 			vforked = 1;
   1127      1.140       kre 	VFORK_BLOCK
   1128       1.61  christos 			switch (pid = vfork()) {
   1129       1.61  christos 			case -1:
   1130      1.108  christos 				serrno = errno;
   1131      1.148       kre 				VTRACE(DBG_EVAL, ("vfork() failed, errno=%d\n",
   1132      1.148       kre 				    serrno));
   1133       1.61  christos 				INTON;
   1134      1.108  christos 				error("Cannot vfork (%s)", strerror(serrno));
   1135       1.61  christos 				break;
   1136       1.61  christos 			case 0:
   1137       1.61  christos 				/* Make sure that exceptions only unwind to
   1138       1.61  christos 				 * after the vfork(2)
   1139       1.61  christos 				 */
   1140      1.140       kre 				SHELL_FORKED();
   1141       1.61  christos 				if (setjmp(jmploc.loc)) {
   1142      1.183       kre 					VTRACE(DBG_EVAL|DBG_ERRS|
   1143      1.183       kre 					  DBG_PROCS|DBG_CMDS|DBG_TRAP,
   1144      1.183       kre 					  ("vfork child exit exception:%d "
   1145      1.183       kre 					   "exitstatus:%d exerrno:%d\n",
   1146      1.183       kre 					   exception, exitstatus, exerrno));
   1147      1.183       kre 
   1148       1.61  christos 					if (exception == EXSHELLPROC) {
   1149      1.148       kre 						/*
   1150      1.148       kre 						 * We can't progress with the
   1151      1.148       kre 						 * vfork, so, set vforked = 2
   1152      1.148       kre 						 * so the parent knows,
   1153      1.148       kre 						 * and _exit();
   1154       1.61  christos 						 */
   1155       1.61  christos 						vforked = 2;
   1156       1.61  christos 						_exit(0);
   1157       1.61  christos 					} else {
   1158      1.161       kre 						_exit(exception == EXEXIT ?
   1159      1.161       kre 						    exitstatus : exerrno);
   1160       1.61  christos 					}
   1161       1.61  christos 				}
   1162       1.61  christos 				savehandler = handler;
   1163       1.61  christos 				handler = &jmploc;
   1164      1.167       kre 				listmklocal(varlist.list,
   1165      1.167       kre 				    VDOEXPORT | VEXPORT | VNOFUNC);
   1166       1.65  christos 				forkchild(jp, cmd, mode, vforked);
   1167       1.61  christos 				break;
   1168       1.61  christos 			default:
   1169      1.140       kre 				VFORK_UNDO();
   1170      1.148       kre 						/* restore from vfork(2) */
   1171      1.174       kre 				CTRACE(DBG_PROCS|DBG_CMDS,
   1172      1.174       kre 				    ("parent after vfork - vforked=%d\n",
   1173      1.174       kre 				      vforked));
   1174      1.148       kre 				handler = savehandler;
   1175       1.61  christos 				poplocalvars();
   1176       1.61  christos 				localvars = savelocalvars;
   1177       1.61  christos 				if (vforked == 2) {
   1178       1.61  christos 					vforked = 0;
   1179       1.61  christos 
   1180       1.61  christos 					(void)waitpid(pid, NULL, 0);
   1181      1.148       kre 					/*
   1182      1.148       kre 					 * We need to progress in a
   1183      1.148       kre 					 * normal fork fashion
   1184      1.148       kre 					 */
   1185       1.61  christos 					goto normal_fork;
   1186       1.61  christos 				}
   1187      1.148       kre 				/*
   1188      1.148       kre 				 * Here the child has left home,
   1189      1.148       kre 				 * getting on with its life, so
   1190      1.148       kre 				 * so must we...
   1191      1.148       kre 				 */
   1192       1.61  christos 				vforked = 0;
   1193       1.65  christos 				forkparent(jp, cmd, mode, pid);
   1194       1.61  christos 				goto parent;
   1195       1.61  christos 			}
   1196      1.140       kre 	VFORK_END
   1197       1.61  christos 		} else {
   1198      1.148       kre  normal_fork:
   1199       1.61  christos #endif
   1200       1.65  christos 			if (forkshell(jp, cmd, mode) != 0)
   1201       1.61  christos 				goto parent;	/* at end of routine */
   1202      1.174       kre 			CTRACE(DBG_PROCS|DBG_CMDS, ("Child sets EV_EXIT\n"));
   1203      1.159       kre 			flags |= EV_EXIT;
   1204       1.66  christos 			FORCEINTON;
   1205       1.61  christos #ifdef DO_SHAREDVFORK
   1206       1.61  christos 		}
   1207       1.61  christos #endif
   1208        1.1       cgd 		if (flags & EV_BACKCMD) {
   1209       1.61  christos 			if (!vforked) {
   1210       1.61  christos 				FORCEINTON;
   1211       1.61  christos 			}
   1212        1.1       cgd 			close(pip[0]);
   1213      1.120  christos 			movefd(pip[1], 1);
   1214        1.1       cgd 		}
   1215        1.1       cgd 		flags |= EV_EXIT;
   1216        1.1       cgd 	}
   1217        1.1       cgd 
   1218        1.1       cgd 	/* This is the child process if a fork occurred. */
   1219        1.1       cgd 	/* Execute the command. */
   1220       1.70       dsl 	switch (cmdentry.cmdtype) {
   1221      1.159       kre 		volatile int saved;
   1222      1.188       kre 		struct funcdef * volatile savefunc;
   1223      1.159       kre 
   1224       1.70       dsl 	case CMDFUNCTION:
   1225      1.152       kre 		VXTRACE(DBG_EVAL, ("Shell function%s:  ",vforked?" VF":""),
   1226      1.152       kre 		    trargs(argv));
   1227      1.159       kre 		redirect(cmd->ncmd.redirect, saved =
   1228      1.159       kre 			!(flags & EV_EXIT) || have_traps() ? REDIR_PUSH : 0);
   1229        1.1       cgd 		saveparam = shellparam;
   1230        1.1       cgd 		shellparam.malloc = 0;
   1231       1.32  christos 		shellparam.reset = 1;
   1232        1.1       cgd 		shellparam.nparam = argc - 1;
   1233        1.1       cgd 		shellparam.p = argv + 1;
   1234        1.1       cgd 		shellparam.optnext = NULL;
   1235        1.1       cgd 		INTOFF;
   1236        1.1       cgd 		savelocalvars = localvars;
   1237        1.1       cgd 		localvars = NULL;
   1238      1.188       kre 		reffunc(savefunc = cmdentry.u.func);
   1239        1.1       cgd 		INTON;
   1240        1.1       cgd 		if (setjmp(jmploc.loc)) {
   1241       1.47  christos 			if (exception == EXSHELLPROC) {
   1242       1.47  christos 				freeparam((volatile struct shparam *)
   1243       1.47  christos 				    &saveparam);
   1244       1.47  christos 			} else {
   1245        1.1       cgd 				freeparam(&shellparam);
   1246        1.1       cgd 				shellparam = saveparam;
   1247        1.1       cgd 			}
   1248      1.159       kre 			if (saved)
   1249      1.180   msaitoh 				popredir();
   1250      1.188       kre 			unreffunc(savefunc);
   1251        1.1       cgd 			poplocalvars();
   1252        1.1       cgd 			localvars = savelocalvars;
   1253      1.143       kre 			funclinebase = savefuncline;
   1254      1.143       kre 			funclineabs = savefuncabs;
   1255        1.1       cgd 			handler = savehandler;
   1256        1.1       cgd 			longjmp(handler->loc, 1);
   1257        1.1       cgd 		}
   1258        1.1       cgd 		savehandler = handler;
   1259        1.1       cgd 		handler = &jmploc;
   1260      1.143       kre 		if (cmdentry.u.func) {
   1261      1.143       kre 			if (cmdentry.lno_frel)
   1262      1.143       kre 				funclinebase = cmdentry.lineno - 1;
   1263      1.143       kre 			else
   1264      1.143       kre 				funclinebase = 0;
   1265      1.143       kre 			funclineabs = cmdentry.lineno;
   1266      1.143       kre 
   1267      1.143       kre 			VTRACE(DBG_EVAL,
   1268      1.143       kre 			  ("function: node: %d '%s' # %d%s; funclinebase=%d\n",
   1269      1.155       kre 			    getfuncnode(cmdentry.u.func)->type,
   1270      1.155       kre 			    NODETYPENAME(getfuncnode(cmdentry.u.func)->type),
   1271      1.143       kre 			    cmdentry.lineno, cmdentry.lno_frel?" (=1)":"",
   1272      1.143       kre 			    funclinebase));
   1273      1.143       kre 		}
   1274      1.167       kre 		listmklocal(varlist.list, VDOEXPORT | VEXPORT);
   1275       1.70       dsl 		/* stop shell blowing its stack */
   1276       1.70       dsl 		if (++funcnest > 1000)
   1277       1.70       dsl 			error("too many nested function calls");
   1278      1.159       kre 		evaltree(getfuncnode(cmdentry.u.func),
   1279      1.159       kre 		    flags & (EV_TESTED|EV_EXIT));
   1280        1.1       cgd 		funcnest--;
   1281        1.1       cgd 		INTOFF;
   1282      1.155       kre 		unreffunc(cmdentry.u.func);
   1283        1.1       cgd 		poplocalvars();
   1284        1.1       cgd 		localvars = savelocalvars;
   1285      1.143       kre 		funclinebase = savefuncline;
   1286      1.143       kre 		funclineabs = savefuncabs;
   1287        1.1       cgd 		freeparam(&shellparam);
   1288        1.1       cgd 		shellparam = saveparam;
   1289        1.1       cgd 		handler = savehandler;
   1290      1.159       kre 		if (saved)
   1291      1.159       kre 			popredir();
   1292        1.1       cgd 		INTON;
   1293        1.1       cgd 		if (evalskip == SKIPFUNC) {
   1294      1.109  christos 			evalskip = SKIPNONE;
   1295        1.1       cgd 			skipcount = 0;
   1296        1.1       cgd 		}
   1297        1.1       cgd 		if (flags & EV_EXIT)
   1298        1.1       cgd 			exitshell(exitstatus);
   1299       1.70       dsl 		break;
   1300       1.70       dsl 
   1301      1.164       kre 	case CMDSPLBLTIN:
   1302      1.164       kre 		VTRACE(DBG_EVAL, ("special "));
   1303       1.70       dsl 	case CMDBUILTIN:
   1304      1.164       kre 		VXTRACE(DBG_EVAL, ("builtin command [%d]%s:  ", argc,
   1305      1.164       kre 		    vforked ? " VF" : ""), trargs(argv));
   1306  1.188.2.2    martin 
   1307  1.188.2.2    martin 		if (cmdentry.u.bltin == execcmd) {
   1308  1.188.2.2    martin 			char **ap;
   1309  1.188.2.2    martin 
   1310  1.188.2.2    martin 			for (ap = argv + 1; *ap != NULL; ap++) {
   1311  1.188.2.2    martin 				if (ap[0][0] != '-')
   1312  1.188.2.2    martin 					break;
   1313  1.188.2.2    martin 				if (ap[0][1] == '\0')
   1314  1.188.2.2    martin 					break;		/* or continue ?? */
   1315  1.188.2.2    martin 				if (ap[0][1] == '-' && ap[0][2] == '\0') {
   1316  1.188.2.2    martin 					ap++;
   1317  1.188.2.2    martin 					break;
   1318  1.188.2.2    martin 				}
   1319  1.188.2.2    martin 			}
   1320  1.188.2.2    martin 
   1321  1.188.2.2    martin 			if (*ap != NULL)
   1322  1.188.2.2    martin 				mode = REDIR_KEEP;	/* exec cmd < ... */
   1323  1.188.2.2    martin 			else
   1324  1.188.2.2    martin 				mode = 0;		/* exec < ... */
   1325  1.188.2.2    martin 		} else
   1326  1.188.2.2    martin 			mode = REDIR_PUSH;
   1327  1.188.2.2    martin 
   1328        1.1       cgd 		if (flags == EV_BACKCMD) {
   1329        1.1       cgd 			memout.nleft = 0;
   1330        1.1       cgd 			memout.nextc = memout.buf;
   1331        1.1       cgd 			memout.bufsize = 64;
   1332        1.1       cgd 			mode |= REDIR_BACKQ;
   1333        1.1       cgd 		}
   1334       1.70       dsl 		e = -1;
   1335      1.169       kre 		savecmdname = commandname;
   1336      1.169       kre 		savetopfile = getcurrentfile();
   1337       1.68  christos 		savehandler = handler;
   1338      1.104     joerg 		temp_path = 0;
   1339       1.68  christos 		if (!setjmp(jmploc.loc)) {
   1340      1.169       kre 			handler = &jmploc;
   1341      1.169       kre 
   1342      1.148       kre 			/*
   1343      1.148       kre 			 * We need to ensure the command hash table isn't
   1344      1.130  christos 			 * corrupted by temporary PATH assignments.
   1345       1.70       dsl 			 * However we must ensure the 'local' command works!
   1346       1.70       dsl 			 */
   1347       1.70       dsl 			if (path != pathval() && (cmdentry.u.bltin == hashcmd ||
   1348       1.70       dsl 			    cmdentry.u.bltin == typecmd)) {
   1349       1.70       dsl 				savelocalvars = localvars;
   1350       1.70       dsl 				localvars = 0;
   1351      1.104     joerg 				temp_path = 1;
   1352       1.70       dsl 				mklocal(path - 5 /* PATH= */, 0);
   1353      1.104     joerg 			}
   1354       1.68  christos 			redirect(cmd->ncmd.redirect, mode);
   1355       1.68  christos 
   1356      1.164       kre 			/*
   1357      1.164       kre 			 * the empty command is regarded as a normal
   1358      1.164       kre 			 * builtin for the purposes of redirects, but
   1359      1.164       kre 			 * is a special builtin for var assigns.
   1360      1.164       kre 			 * (unless we are the "command" command.)
   1361      1.164       kre 			 */
   1362      1.164       kre 			if (argc == 0 && !(cmd_flags & DO_NOFUNC))
   1363      1.164       kre 				cmdentry.cmdtype = CMDSPLBLTIN;
   1364      1.164       kre 
   1365       1.68  christos 			/* exec is a special builtin, but needs this list... */
   1366       1.68  christos 			cmdenviron = varlist.list;
   1367       1.68  christos 			/* we must check 'readonly' flag for all builtins */
   1368       1.68  christos 			listsetvar(varlist.list,
   1369       1.68  christos 				cmdentry.cmdtype == CMDSPLBLTIN ? 0 : VNOSET);
   1370       1.68  christos 			commandname = argv[0];
   1371       1.68  christos 			/* initialize nextopt */
   1372       1.68  christos 			argptr = argv + 1;
   1373       1.68  christos 			optptr = NULL;
   1374       1.68  christos 			/* and getopt */
   1375       1.68  christos 			optreset = 1;
   1376       1.68  christos 			optind = 1;
   1377      1.103  christos 			builtin_flags = flags;
   1378      1.185       kre 			clr_err(out1);	/* discard previous I/O errors */
   1379       1.68  christos 			exitstatus = cmdentry.u.bltin(argc, argv);
   1380       1.68  christos 		} else {
   1381        1.1       cgd 			e = exception;
   1382      1.159       kre 			if (e == EXINT)
   1383      1.159       kre 				exitstatus = SIGINT + 128;
   1384      1.159       kre 			else if (e == EXEXEC)
   1385      1.159       kre 				exitstatus = exerrno;
   1386      1.159       kre 			else if (e != EXEXIT)
   1387      1.159       kre 				exitstatus = 2;
   1388        1.1       cgd 		}
   1389       1.70       dsl 		handler = savehandler;
   1390        1.1       cgd 		flushall();
   1391        1.1       cgd 		out1 = &output;
   1392        1.1       cgd 		out2 = &errout;
   1393        1.1       cgd 		freestdout();
   1394       1.70       dsl 		if (temp_path) {
   1395       1.70       dsl 			poplocalvars();
   1396       1.70       dsl 			localvars = savelocalvars;
   1397       1.70       dsl 		}
   1398       1.39   thorpej 		cmdenviron = NULL;
   1399        1.1       cgd 		if (e != EXSHELLPROC) {
   1400        1.1       cgd 			commandname = savecmdname;
   1401       1.44   mycroft 			if (flags & EV_EXIT)
   1402        1.1       cgd 				exitshell(exitstatus);
   1403        1.1       cgd 		}
   1404        1.1       cgd 		if (e != -1) {
   1405       1.31  christos 			if ((e != EXERROR && e != EXEXEC)
   1406       1.70       dsl 			    || cmdentry.cmdtype == CMDSPLBLTIN)
   1407        1.1       cgd 				exraise(e);
   1408      1.169       kre 			popfilesupto(savetopfile);
   1409        1.1       cgd 			FORCEINTON;
   1410        1.1       cgd 		}
   1411       1.68  christos 		if (cmdentry.u.bltin != execcmd)
   1412        1.1       cgd 			popredir();
   1413        1.1       cgd 		if (flags == EV_BACKCMD) {
   1414        1.1       cgd 			backcmd->buf = memout.buf;
   1415        1.1       cgd 			backcmd->nleft = memout.nextc - memout.buf;
   1416        1.1       cgd 			memout.buf = NULL;
   1417        1.1       cgd 		}
   1418       1.70       dsl 		break;
   1419       1.70       dsl 
   1420       1.70       dsl 	default:
   1421      1.152       kre 		VXTRACE(DBG_EVAL, ("normal command%s:  ", vforked?" VF":""),
   1422      1.152       kre 		    trargs(argv));
   1423      1.117  christos 		redirect(cmd->ncmd.redirect,
   1424      1.117  christos 		    (vforked ? REDIR_VFORK : 0) | REDIR_KEEP);
   1425       1.61  christos 		if (!vforked)
   1426       1.61  christos 			for (sp = varlist.list ; sp ; sp = sp->next)
   1427      1.167       kre 				setvareq(sp->text, VDOEXPORT|VEXPORT|VSTACK);
   1428        1.1       cgd 		envp = environment();
   1429       1.70       dsl 		shellexec(argv, envp, path, cmdentry.u.index, vforked);
   1430       1.70       dsl 		break;
   1431        1.1       cgd 	}
   1432        1.1       cgd 	goto out;
   1433        1.1       cgd 
   1434      1.148       kre  parent:			/* parent process gets here (if we forked) */
   1435      1.148       kre 
   1436      1.113  christos 	exitstatus = 0;		/* if not altered just below */
   1437       1.68  christos 	if (mode == FORK_FG) {	/* argument to fork */
   1438        1.1       cgd 		exitstatus = waitforjob(jp);
   1439       1.68  christos 	} else if (mode == FORK_NOJOB) {
   1440        1.1       cgd 		backcmd->fd = pip[0];
   1441        1.1       cgd 		close(pip[1]);
   1442        1.1       cgd 		backcmd->jp = jp;
   1443        1.1       cgd 	}
   1444       1.66  christos 	FORCEINTON;
   1445        1.1       cgd 
   1446      1.148       kre  out:
   1447        1.1       cgd 	if (lastarg)
   1448      1.132       kre 		/* implement $_ for whatever use that really is */
   1449      1.147       kre 		(void) setvarsafe("_", lastarg, VNOERROR);
   1450        1.1       cgd 	popstackmark(&smark);
   1451        1.1       cgd }
   1452        1.1       cgd 
   1453        1.1       cgd 
   1454        1.1       cgd /*
   1455        1.1       cgd  * Search for a command.  This is called before we fork so that the
   1456        1.1       cgd  * location of the command will be available in the parent as well as
   1457        1.1       cgd  * the child.  The check for "goodname" is an overly conservative
   1458        1.1       cgd  * check that the name will not be subject to expansion.
   1459        1.1       cgd  */
   1460        1.1       cgd 
   1461        1.1       cgd STATIC void
   1462       1.68  christos prehash(union node *n)
   1463       1.22  christos {
   1464        1.1       cgd 	struct cmdentry entry;
   1465        1.1       cgd 
   1466       1.86  christos 	if (n && n->type == NCMD && n->ncmd.args)
   1467       1.15   mycroft 		if (goodname(n->ncmd.args->narg.text))
   1468       1.26  christos 			find_command(n->ncmd.args->narg.text, &entry, 0,
   1469       1.26  christos 				     pathval());
   1470        1.1       cgd }
   1471        1.1       cgd 
   1472      1.122       kre int
   1473      1.109  christos in_function(void)
   1474      1.109  christos {
   1475      1.109  christos 	return funcnest;
   1476      1.109  christos }
   1477        1.1       cgd 
   1478      1.122       kre enum skipstate
   1479      1.109  christos current_skipstate(void)
   1480      1.109  christos {
   1481      1.109  christos 	return evalskip;
   1482      1.109  christos }
   1483      1.109  christos 
   1484      1.122       kre void
   1485      1.168       kre save_skipstate(struct skipsave *p)
   1486      1.168       kre {
   1487      1.168       kre 	*p = s_k_i_p;
   1488      1.168       kre }
   1489      1.168       kre 
   1490      1.168       kre void
   1491      1.168       kre restore_skipstate(const struct skipsave *p)
   1492      1.168       kre {
   1493      1.168       kre 	s_k_i_p = *p;
   1494      1.168       kre }
   1495      1.168       kre 
   1496      1.168       kre void
   1497      1.109  christos stop_skipping(void)
   1498      1.109  christos {
   1499      1.109  christos 	evalskip = SKIPNONE;
   1500      1.109  christos 	skipcount = 0;
   1501      1.109  christos }
   1502        1.1       cgd 
   1503        1.1       cgd /*
   1504        1.1       cgd  * Builtin commands.  Builtin commands whose functions are closely
   1505        1.1       cgd  * tied to evaluation are implemented here.
   1506        1.1       cgd  */
   1507        1.1       cgd 
   1508        1.1       cgd /*
   1509       1.70       dsl  * No command given.
   1510        1.1       cgd  */
   1511        1.1       cgd 
   1512       1.16       cgd int
   1513       1.68  christos bltincmd(int argc, char **argv)
   1514       1.16       cgd {
   1515       1.31  christos 	/*
   1516       1.22  christos 	 * Preserve exitstatus of a previous possible redirection
   1517       1.31  christos 	 * as POSIX mandates
   1518       1.22  christos 	 */
   1519       1.68  christos 	return back_exitstatus;
   1520        1.1       cgd }
   1521        1.1       cgd 
   1522        1.1       cgd 
   1523        1.1       cgd /*
   1524        1.1       cgd  * Handle break and continue commands.  Break, continue, and return are
   1525        1.1       cgd  * all handled by setting the evalskip flag.  The evaluation routines
   1526        1.1       cgd  * above all check this flag, and if it is set they start skipping
   1527        1.1       cgd  * commands rather than executing them.  The variable skipcount is
   1528        1.1       cgd  * the number of loops to break/continue, or the number of function
   1529        1.1       cgd  * levels to return.  (The latter is always 1.)  It should probably
   1530        1.1       cgd  * be an error to break out of more loops than exist, but it isn't
   1531        1.1       cgd  * in the standard shell so we don't make it one here.
   1532        1.1       cgd  */
   1533        1.1       cgd 
   1534       1.16       cgd int
   1535       1.68  christos breakcmd(int argc, char **argv)
   1536       1.16       cgd {
   1537       1.30  christos 	int n = argc > 1 ? number(argv[1]) : 1;
   1538        1.1       cgd 
   1539      1.135       kre 	if (n <= 0)
   1540      1.135       kre 		error("invalid count: %d", n);
   1541        1.1       cgd 	if (n > loopnest)
   1542        1.1       cgd 		n = loopnest;
   1543        1.1       cgd 	if (n > 0) {
   1544        1.1       cgd 		evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK;
   1545        1.1       cgd 		skipcount = n;
   1546        1.1       cgd 	}
   1547        1.1       cgd 	return 0;
   1548        1.1       cgd }
   1549        1.1       cgd 
   1550      1.109  christos int
   1551      1.109  christos dotcmd(int argc, char **argv)
   1552      1.109  christos {
   1553      1.109  christos 	exitstatus = 0;
   1554      1.109  christos 
   1555      1.178       kre 	(void) nextopt(NULL);		/* ignore a leading "--" */
   1556      1.178       kre 
   1557      1.178       kre 	if (*argptr != NULL) {		/* That's what SVR2 does */
   1558      1.109  christos 		char *fullname;
   1559      1.109  christos 		/*
   1560      1.109  christos 		 * dot_funcnest needs to be 0 when not in a dotcmd, so it
   1561      1.109  christos 		 * cannot be restored with (funcnest + 1).
   1562      1.109  christos 		 */
   1563      1.109  christos 		int dot_funcnest_old;
   1564      1.109  christos 		struct stackmark smark;
   1565      1.109  christos 
   1566      1.109  christos 		setstackmark(&smark);
   1567      1.178       kre 		fullname = find_dot_file(*argptr);
   1568      1.109  christos 		setinputfile(fullname, 1);
   1569      1.109  christos 		commandname = fullname;
   1570      1.109  christos 		dot_funcnest_old = dot_funcnest;
   1571      1.109  christos 		dot_funcnest = funcnest + 1;
   1572      1.109  christos 		cmdloop(0);
   1573      1.109  christos 		dot_funcnest = dot_funcnest_old;
   1574      1.109  christos 		popfile();
   1575      1.109  christos 		popstackmark(&smark);
   1576      1.109  christos 	}
   1577      1.109  christos 	return exitstatus;
   1578      1.109  christos }
   1579      1.109  christos 
   1580      1.109  christos /*
   1581      1.171       kre  * allow dotfile function nesting to be manipulated
   1582      1.171       kre  * (for read_profile).  This allows profile files to
   1583      1.171       kre  * be treated as if they were used as '.' commands,
   1584      1.171       kre  * (approximately) and in particular, for "return" to work.
   1585      1.171       kre  */
   1586      1.171       kre int
   1587      1.171       kre set_dot_funcnest(int new)
   1588      1.171       kre {
   1589      1.171       kre 	int rv = dot_funcnest;
   1590      1.171       kre 
   1591      1.171       kre 	if (new >= 0)
   1592      1.171       kre 		dot_funcnest = new;
   1593      1.171       kre 
   1594      1.171       kre 	return rv;
   1595      1.171       kre }
   1596      1.171       kre 
   1597      1.171       kre /*
   1598      1.109  christos  * Take commands from a file.  To be compatible we should do a path
   1599      1.109  christos  * search for the file, which is necessary to find sub-commands.
   1600      1.109  christos  */
   1601      1.109  christos 
   1602      1.109  christos STATIC char *
   1603      1.109  christos find_dot_file(char *basename)
   1604      1.109  christos {
   1605      1.109  christos 	char *fullname;
   1606      1.109  christos 	const char *path = pathval();
   1607      1.109  christos 	struct stat statb;
   1608      1.109  christos 
   1609      1.109  christos 	/* don't try this for absolute or relative paths */
   1610      1.121       kre 	if (strchr(basename, '/')) {
   1611      1.121       kre 		if (stat(basename, &statb) == 0) {
   1612      1.128       kre 			if (S_ISDIR(statb.st_mode))
   1613      1.128       kre 				error("%s: is a directory", basename);
   1614      1.128       kre 			if (S_ISBLK(statb.st_mode))
   1615      1.128       kre 				error("%s: is a block device", basename);
   1616      1.128       kre 			return basename;
   1617      1.121       kre 		}
   1618      1.141       kre 	} else while ((fullname = padvance(&path, basename, 1)) != NULL) {
   1619      1.128       kre 		if ((stat(fullname, &statb) == 0)) {
   1620      1.128       kre 			/* weird format is to ease future code... */
   1621      1.128       kre 			if (S_ISDIR(statb.st_mode) || S_ISBLK(statb.st_mode))
   1622      1.128       kre 				;
   1623      1.128       kre #if notyet
   1624      1.128       kre 			else if (unreadable()) {
   1625      1.128       kre 				/*
   1626      1.128       kre 				 * testing this via st_mode is ugly to get
   1627      1.128       kre 				 * correct (and would ignore ACLs).
   1628      1.128       kre 				 * better way is just to open the file.
   1629      1.128       kre 				 * But doing that here would (currently)
   1630      1.128       kre 				 * mean opening the file twice, which
   1631      1.128       kre 				 * might not be safe.  So, defer this
   1632      1.128       kre 				 * test until code is restructures so
   1633      1.128       kre 				 * we can return a fd.   Then we also
   1634      1.128       kre 				 * get to fix the mem leak just below...
   1635      1.128       kre 				 */
   1636      1.128       kre 			}
   1637      1.128       kre #endif
   1638      1.128       kre 			else {
   1639      1.128       kre 				/*
   1640      1.128       kre 				 * Don't bother freeing here, since
   1641      1.128       kre 				 * it will be freed by the caller.
   1642      1.128       kre 				 * XXX no it won't - a bug for later.
   1643      1.128       kre 				 */
   1644      1.128       kre 				return fullname;
   1645      1.128       kre 			}
   1646      1.109  christos 		}
   1647      1.109  christos 		stunalloc(fullname);
   1648      1.109  christos 	}
   1649      1.109  christos 
   1650      1.109  christos 	/* not found in the PATH */
   1651      1.109  christos 	error("%s: not found", basename);
   1652      1.109  christos 	/* NOTREACHED */
   1653      1.109  christos }
   1654      1.109  christos 
   1655      1.109  christos 
   1656        1.1       cgd 
   1657        1.1       cgd /*
   1658        1.1       cgd  * The return command.
   1659      1.109  christos  *
   1660      1.109  christos  * Quoth the POSIX standard:
   1661      1.109  christos  *   The return utility shall cause the shell to stop executing the current
   1662      1.109  christos  *   function or dot script. If the shell is not currently executing
   1663      1.109  christos  *   a function or dot script, the results are unspecified.
   1664      1.109  christos  *
   1665      1.109  christos  * As for the unspecified part, there seems to be no de-facto standard: bash
   1666      1.109  christos  * ignores the return with a warning, zsh ignores the return in interactive
   1667      1.109  christos  * mode but seems to liken it to exit in a script.  (checked May 2014)
   1668      1.109  christos  *
   1669      1.109  christos  * We choose to silently ignore the return.  Older versions of this shell
   1670      1.109  christos  * set evalskip to SKIPFILE causing the shell to (indirectly) exit.  This
   1671      1.109  christos  * had at least the problem of circumventing the check for stopped jobs,
   1672      1.109  christos  * which would occur for exit or ^D.
   1673        1.1       cgd  */
   1674        1.1       cgd 
   1675       1.16       cgd int
   1676       1.68  christos returncmd(int argc, char **argv)
   1677       1.16       cgd {
   1678       1.68  christos 	int ret = argc > 1 ? number(argv[1]) : exitstatus;
   1679        1.1       cgd 
   1680      1.109  christos 	if ((dot_funcnest == 0 && funcnest)
   1681      1.109  christos 	    || (dot_funcnest > 0 && funcnest - (dot_funcnest - 1) > 0)) {
   1682        1.1       cgd 		evalskip = SKIPFUNC;
   1683        1.1       cgd 		skipcount = 1;
   1684      1.109  christos 	} else if (dot_funcnest > 0) {
   1685       1.27  christos 		evalskip = SKIPFILE;
   1686       1.27  christos 		skipcount = 1;
   1687      1.109  christos 	} else {
   1688      1.109  christos 		/* XXX: should a warning be issued? */
   1689      1.109  christos 		ret = 0;
   1690        1.1       cgd 	}
   1691      1.109  christos 
   1692      1.109  christos 	return ret;
   1693        1.1       cgd }
   1694        1.1       cgd 
   1695        1.1       cgd 
   1696       1.16       cgd int
   1697       1.68  christos falsecmd(int argc, char **argv)
   1698       1.16       cgd {
   1699        1.8       jtc 	return 1;
   1700        1.8       jtc }
   1701        1.8       jtc 
   1702        1.8       jtc 
   1703       1.16       cgd int
   1704       1.68  christos truecmd(int argc, char **argv)
   1705       1.16       cgd {
   1706        1.1       cgd 	return 0;
   1707        1.1       cgd }
   1708        1.1       cgd 
   1709        1.1       cgd 
   1710       1.16       cgd int
   1711       1.68  christos execcmd(int argc, char **argv)
   1712       1.16       cgd {
   1713      1.178       kre 	(void) nextopt(NULL);		/* ignore a leading "--" */
   1714      1.178       kre 
   1715      1.178       kre 	if (*argptr) {
   1716       1.20  christos 		struct strlist *sp;
   1717       1.20  christos 
   1718        1.1       cgd 		iflag = 0;		/* exit on error */
   1719        1.7       jtc 		mflag = 0;
   1720        1.7       jtc 		optschanged();
   1721       1.70       dsl 		for (sp = cmdenviron; sp; sp = sp->next)
   1722      1.167       kre 			setvareq(sp->text, VDOEXPORT|VEXPORT|VSTACK);
   1723      1.178       kre 		shellexec(argptr, environment(), pathval(), 0, 0);
   1724        1.1       cgd 	}
   1725       1.68  christos 	return 0;
   1726       1.68  christos }
   1727       1.68  christos 
   1728       1.68  christos static int
   1729       1.73    itojun conv_time(clock_t ticks, char *seconds, size_t l)
   1730       1.68  christos {
   1731       1.68  christos 	static clock_t tpm = 0;
   1732       1.68  christos 	clock_t mins;
   1733       1.68  christos 	int i;
   1734       1.68  christos 
   1735       1.68  christos 	if (!tpm)
   1736       1.68  christos 		tpm = sysconf(_SC_CLK_TCK) * 60;
   1737       1.68  christos 
   1738       1.68  christos 	mins = ticks / tpm;
   1739       1.73    itojun 	snprintf(seconds, l, "%.4f", (ticks - mins * tpm) * 60.0 / tpm );
   1740       1.68  christos 
   1741       1.68  christos 	if (seconds[0] == '6' && seconds[1] == '0') {
   1742       1.68  christos 		/* 59.99995 got rounded up... */
   1743       1.68  christos 		mins++;
   1744       1.73    itojun 		strlcpy(seconds, "0.0", l);
   1745       1.68  christos 		return mins;
   1746       1.68  christos 	}
   1747       1.68  christos 
   1748       1.68  christos 	/* suppress trailing zeros */
   1749       1.68  christos 	i = strlen(seconds) - 1;
   1750       1.68  christos 	for (; seconds[i] == '0' && seconds[i - 1] != '.'; i--)
   1751       1.68  christos 		seconds[i] = 0;
   1752       1.68  christos 	return mins;
   1753       1.68  christos }
   1754       1.68  christos 
   1755       1.68  christos int
   1756       1.68  christos timescmd(int argc, char **argv)
   1757       1.68  christos {
   1758       1.68  christos 	struct tms tms;
   1759       1.68  christos 	int u, s, cu, cs;
   1760       1.68  christos 	char us[8], ss[8], cus[8], css[8];
   1761       1.68  christos 
   1762       1.68  christos 	nextopt("");
   1763       1.68  christos 
   1764       1.68  christos 	times(&tms);
   1765       1.68  christos 
   1766       1.73    itojun 	u = conv_time(tms.tms_utime, us, sizeof(us));
   1767       1.73    itojun 	s = conv_time(tms.tms_stime, ss, sizeof(ss));
   1768       1.73    itojun 	cu = conv_time(tms.tms_cutime, cus, sizeof(cus));
   1769       1.73    itojun 	cs = conv_time(tms.tms_cstime, css, sizeof(css));
   1770       1.68  christos 
   1771       1.68  christos 	outfmt(out1, "%dm%ss %dm%ss\n%dm%ss %dm%ss\n",
   1772       1.68  christos 		u, us, s, ss, cu, cus, cs, css);
   1773       1.68  christos 
   1774        1.1       cgd 	return 0;
   1775        1.1       cgd }
   1776