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eval.c revision 1.188
      1  1.188       kre /*	$NetBSD: eval.c,v 1.188 2022/01/05 15:25:44 kre 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       kre __RCSID("$NetBSD: eval.c,v 1.188 2022/01/05 15:25:44 kre 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   1.68  christos 		expandarg(argp, &varlist, EXP_VARTILDE);
    936   1.68  christos 	}
    937    1.1       cgd 	*varlist.lastp = NULL;
    938   1.68  christos 
    939    1.1       cgd 	argc = 0;
    940    1.1       cgd 	for (sp = arglist.list ; sp ; sp = sp->next)
    941    1.1       cgd 		argc++;
    942    1.1       cgd 	argv = stalloc(sizeof (char *) * (argc + 1));
    943    1.7       jtc 
    944    1.7       jtc 	for (sp = arglist.list ; sp ; sp = sp->next) {
    945  1.148       kre 		VTRACE(DBG_EVAL, ("evalcommand arg: %s\n", sp->text));
    946    1.1       cgd 		*argv++ = sp->text;
    947    1.7       jtc 	}
    948    1.1       cgd 	*argv = NULL;
    949    1.1       cgd 	lastarg = NULL;
    950    1.1       cgd 	if (iflag && funcnest == 0 && argc > 0)
    951    1.1       cgd 		lastarg = argv[-1];
    952    1.1       cgd 	argv -= argc;
    953    1.1       cgd 
    954    1.1       cgd 	/* Print the command if xflag is set. */
    955    1.1       cgd 	if (xflag) {
    956   1.70       dsl 		char sep = 0;
    957  1.151       kre 		union node *rn;
    958  1.151       kre 
    959  1.153       kre 		outxstr(expandstr(ps4val(), line_number));
    960    1.1       cgd 		for (sp = varlist.list ; sp ; sp = sp->next) {
    961  1.116  christos 			char *p;
    962  1.116  christos 
    963   1.70       dsl 			if (sep != 0)
    964  1.153       kre 				outxc(sep);
    965  1.116  christos 
    966  1.116  christos 			/*
    967  1.116  christos 			 * The "var=" part should not be quoted, regardless
    968  1.116  christos 			 * of the value, or it would not represent an
    969  1.116  christos 			 * assignment, but rather a command
    970  1.116  christos 			 */
    971  1.116  christos 			p = strchr(sp->text, '=');
    972  1.116  christos 			if (p != NULL) {
    973  1.116  christos 				*p = '\0';	/*XXX*/
    974  1.153       kre 				outxshstr(sp->text);
    975  1.153       kre 				outxc('=');
    976  1.116  christos 				*p++ = '=';	/*XXX*/
    977  1.116  christos 			} else
    978  1.116  christos 				p = sp->text;
    979  1.153       kre 			outxshstr(p);
    980   1.70       dsl 			sep = ' ';
    981    1.1       cgd 		}
    982    1.1       cgd 		for (sp = arglist.list ; sp ; sp = sp->next) {
    983   1.70       dsl 			if (sep != 0)
    984  1.153       kre 				outxc(sep);
    985  1.153       kre 			outxshstr(sp->text);
    986   1.70       dsl 			sep = ' ';
    987    1.1       cgd 		}
    988  1.151       kre 		for (rn = cmd->ncmd.redirect; rn; rn = rn->nfile.next)
    989  1.153       kre 			if (outredir(outx, rn, sep))
    990  1.151       kre 				sep = ' ';
    991  1.153       kre 		outxc('\n');
    992  1.153       kre 		flushout(outx);
    993    1.1       cgd 	}
    994    1.1       cgd 
    995    1.1       cgd 	/* Now locate the command. */
    996    1.1       cgd 	if (argc == 0) {
    997  1.164       kre 		/*
    998  1.164       kre 		 * the empty command begins as a normal builtin, and
    999  1.164       kre 		 * remains that way while redirects are processed, then
   1000  1.164       kre 		 * will become special before we get to doing the
   1001  1.164       kre 		 * var assigns.
   1002  1.164       kre 		 */
   1003  1.164       kre 		cmdentry.cmdtype = CMDBUILTIN;
   1004   1.68  christos 		cmdentry.u.bltin = bltincmd;
   1005  1.174       kre 		VTRACE(DBG_CMDS, ("No command name, assume \"comamnd\"\n"));
   1006    1.1       cgd 	} else {
   1007   1.26  christos 		static const char PATH[] = "PATH=";
   1008   1.26  christos 
   1009   1.26  christos 		/*
   1010   1.26  christos 		 * Modify the command lookup path, if a PATH= assignment
   1011   1.26  christos 		 * is present
   1012   1.26  christos 		 */
   1013   1.70       dsl 		for (sp = varlist.list; sp; sp = sp->next)
   1014   1.26  christos 			if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0)
   1015   1.26  christos 				path = sp->text + sizeof(PATH) - 1;
   1016   1.26  christos 
   1017   1.70       dsl 		do {
   1018   1.70       dsl 			int argsused, use_syspath;
   1019  1.143       kre 
   1020   1.70       dsl 			find_command(argv[0], &cmdentry, cmd_flags, path);
   1021  1.174       kre 			VTRACE(DBG_CMDS, ("Command %s type %d\n", argv[0],
   1022  1.174       kre 			    cmdentry.cmdtype));
   1023  1.157       kre #if 0
   1024  1.157       kre 			/*
   1025  1.157       kre 			 * This short circuits all of the processing that
   1026  1.157       kre 			 * should be done (including processing the
   1027  1.157       kre 			 * redirects), so just don't ...
   1028  1.157       kre 			 *
   1029  1.157       kre 			 * (eventually this whole #if'd block will vanish)
   1030  1.157       kre 			 */
   1031   1.70       dsl 			if (cmdentry.cmdtype == CMDUNKNOWN) {
   1032   1.68  christos 				exitstatus = 127;
   1033   1.68  christos 				flushout(&errout);
   1034   1.70       dsl 				goto out;
   1035    1.1       cgd 			}
   1036  1.157       kre #endif
   1037   1.70       dsl 
   1038   1.70       dsl 			/* implement the 'command' builtin here */
   1039   1.70       dsl 			if (cmdentry.cmdtype != CMDBUILTIN ||
   1040   1.70       dsl 			    cmdentry.u.bltin != bltincmd)
   1041   1.70       dsl 				break;
   1042  1.174       kre 			VTRACE(DBG_CMDS, ("Command \"command\"\n"));
   1043   1.70       dsl 			cmd_flags |= DO_NOFUNC;
   1044   1.70       dsl 			argsused = parse_command_args(argc, argv, &use_syspath);
   1045   1.70       dsl 			if (argsused == 0) {
   1046  1.154       kre 				/* use 'type' builtin to display info */
   1047  1.174       kre 				VTRACE(DBG_CMDS,
   1048  1.174       kre 				    ("Command \"command\" -> \"type\"\n"));
   1049   1.70       dsl 				cmdentry.u.bltin = typecmd;
   1050   1.70       dsl 				break;
   1051   1.70       dsl 			}
   1052   1.70       dsl 			argc -= argsused;
   1053   1.70       dsl 			argv += argsused;
   1054   1.70       dsl 			if (use_syspath)
   1055   1.70       dsl 				path = syspath() + 5;
   1056   1.70       dsl 		} while (argc != 0);
   1057   1.70       dsl 		if (cmdentry.cmdtype == CMDSPLBLTIN && cmd_flags & DO_NOFUNC)
   1058   1.70       dsl 			/* posix mandates that 'command <splbltin>' act as if
   1059   1.70       dsl 			   <splbltin> was a normal builtin */
   1060   1.70       dsl 			cmdentry.cmdtype = CMDBUILTIN;
   1061    1.1       cgd 	}
   1062    1.1       cgd 
   1063  1.170       kre 	/*
   1064  1.170       kre 	 * When traps are invalid, we permit the following:
   1065  1.170       kre 	 *	trap
   1066  1.170       kre 	 *	command trap
   1067  1.170       kre 	 *	eval trap
   1068  1.170       kre 	 *	command eval trap
   1069  1.170       kre 	 *	eval command trap
   1070  1.170       kre 	 * without zapping the traps completely, in all other cases we do.
   1071  1.181       kre 	 * Function calls also do not zap the traps (but commands they execute
   1072  1.181       kre 	 * probably will) - this allows a function like
   1073  1.181       kre 	 *	trapstate() { trap -p; }
   1074  1.181       kre 	 * called as save_traps=$(trapstate).
   1075  1.170       kre 	 *
   1076  1.170       kre 	 * The test here permits eval "anything" but when evalstring() comes
   1077  1.170       kre 	 * back here again, the "anything" will be validated.
   1078  1.170       kre 	 * This means we can actually do:
   1079  1.170       kre 	 *	eval eval eval command eval eval command trap
   1080  1.170       kre 	 * as long as we end up with just "trap"
   1081  1.170       kre 	 *
   1082  1.170       kre 	 * We permit "command" by allowing CMDBUILTIN as well as CMDSPLBLTIN
   1083  1.170       kre 	 *
   1084  1.170       kre 	 * trapcmd() takes care of doing free_traps() if it is needed there.
   1085  1.170       kre 	 */
   1086  1.170       kre 	if (traps_invalid &&
   1087  1.181       kre 	    cmdentry.cmdtype != CMDFUNCTION &&
   1088  1.170       kre 	    ((cmdentry.cmdtype!=CMDSPLBLTIN && cmdentry.cmdtype!=CMDBUILTIN) ||
   1089  1.170       kre 	     (cmdentry.u.bltin != trapcmd && cmdentry.u.bltin != evalcmd)))
   1090  1.168       kre 		free_traps();
   1091  1.168       kre 
   1092    1.1       cgd 	/* Fork off a child process if necessary. */
   1093  1.176       kre 	if (cmd->ncmd.backgnd
   1094  1.176       kre 	  || ((cmdentry.cmdtype == CMDNORMAL || cmdentry.cmdtype == CMDUNKNOWN)
   1095  1.176       kre 	     && (have_traps() || (flags & EV_EXIT) == 0))
   1096  1.176       kre #ifdef notyet			/* EV_BACKCMD is never set currently */
   1097  1.176       kre 			/* this will need more work if/when it gets used */
   1098  1.176       kre 	  || ((flags & EV_BACKCMD) != 0
   1099  1.176       kre 	     && (cmdentry.cmdtype != CMDBUILTIN
   1100  1.176       kre 	         && cmdentry.cmdtype != CMDSPLBLTIN)
   1101  1.176       kre 	       || cmdentry.u.bltin == dotcmd
   1102  1.176       kre 	       || cmdentry.u.bltin == evalcmd)
   1103  1.176       kre #endif
   1104  1.176       kre 	 ) {
   1105   1.62  christos 		INTOFF;
   1106    1.1       cgd 		jp = makejob(cmd, 1);
   1107    1.1       cgd 		mode = cmd->ncmd.backgnd;
   1108    1.1       cgd 		if (flags & EV_BACKCMD) {
   1109    1.1       cgd 			mode = FORK_NOJOB;
   1110   1.76       dsl 			if (sh_pipe(pip) < 0)
   1111    1.1       cgd 				error("Pipe call failed");
   1112    1.1       cgd 		}
   1113   1.61  christos #ifdef DO_SHAREDVFORK
   1114   1.61  christos 		/* It is essential that if DO_SHAREDVFORK is defined that the
   1115   1.61  christos 		 * child's address space is actually shared with the parent as
   1116   1.61  christos 		 * we rely on this.
   1117   1.61  christos 		 */
   1118  1.177       kre 		if (usefork == 0 && cmdentry.cmdtype == CMDNORMAL &&
   1119  1.177       kre 		    (!cmd->ncmd.backgnd || cmd->ncmd.redirect == NULL)) {
   1120   1.61  christos 			pid_t	pid;
   1121  1.108  christos 			int serrno;
   1122   1.61  christos 
   1123   1.61  christos 			savelocalvars = localvars;
   1124   1.61  christos 			localvars = NULL;
   1125   1.61  christos 			vforked = 1;
   1126  1.140       kre 	VFORK_BLOCK
   1127   1.61  christos 			switch (pid = vfork()) {
   1128   1.61  christos 			case -1:
   1129  1.108  christos 				serrno = errno;
   1130  1.148       kre 				VTRACE(DBG_EVAL, ("vfork() failed, errno=%d\n",
   1131  1.148       kre 				    serrno));
   1132   1.61  christos 				INTON;
   1133  1.108  christos 				error("Cannot vfork (%s)", strerror(serrno));
   1134   1.61  christos 				break;
   1135   1.61  christos 			case 0:
   1136   1.61  christos 				/* Make sure that exceptions only unwind to
   1137   1.61  christos 				 * after the vfork(2)
   1138   1.61  christos 				 */
   1139  1.140       kre 				SHELL_FORKED();
   1140   1.61  christos 				if (setjmp(jmploc.loc)) {
   1141  1.183       kre 					VTRACE(DBG_EVAL|DBG_ERRS|
   1142  1.183       kre 					  DBG_PROCS|DBG_CMDS|DBG_TRAP,
   1143  1.183       kre 					  ("vfork child exit exception:%d "
   1144  1.183       kre 					   "exitstatus:%d exerrno:%d\n",
   1145  1.183       kre 					   exception, exitstatus, exerrno));
   1146  1.183       kre 
   1147   1.61  christos 					if (exception == EXSHELLPROC) {
   1148  1.148       kre 						/*
   1149  1.148       kre 						 * We can't progress with the
   1150  1.148       kre 						 * vfork, so, set vforked = 2
   1151  1.148       kre 						 * so the parent knows,
   1152  1.148       kre 						 * and _exit();
   1153   1.61  christos 						 */
   1154   1.61  christos 						vforked = 2;
   1155   1.61  christos 						_exit(0);
   1156   1.61  christos 					} else {
   1157  1.161       kre 						_exit(exception == EXEXIT ?
   1158  1.161       kre 						    exitstatus : exerrno);
   1159   1.61  christos 					}
   1160   1.61  christos 				}
   1161   1.61  christos 				savehandler = handler;
   1162   1.61  christos 				handler = &jmploc;
   1163  1.167       kre 				listmklocal(varlist.list,
   1164  1.167       kre 				    VDOEXPORT | VEXPORT | VNOFUNC);
   1165   1.65  christos 				forkchild(jp, cmd, mode, vforked);
   1166   1.61  christos 				break;
   1167   1.61  christos 			default:
   1168  1.140       kre 				VFORK_UNDO();
   1169  1.148       kre 						/* restore from vfork(2) */
   1170  1.174       kre 				CTRACE(DBG_PROCS|DBG_CMDS,
   1171  1.174       kre 				    ("parent after vfork - vforked=%d\n",
   1172  1.174       kre 				      vforked));
   1173  1.148       kre 				handler = savehandler;
   1174   1.61  christos 				poplocalvars();
   1175   1.61  christos 				localvars = savelocalvars;
   1176   1.61  christos 				if (vforked == 2) {
   1177   1.61  christos 					vforked = 0;
   1178   1.61  christos 
   1179   1.61  christos 					(void)waitpid(pid, NULL, 0);
   1180  1.148       kre 					/*
   1181  1.148       kre 					 * We need to progress in a
   1182  1.148       kre 					 * normal fork fashion
   1183  1.148       kre 					 */
   1184   1.61  christos 					goto normal_fork;
   1185   1.61  christos 				}
   1186  1.148       kre 				/*
   1187  1.148       kre 				 * Here the child has left home,
   1188  1.148       kre 				 * getting on with its life, so
   1189  1.148       kre 				 * so must we...
   1190  1.148       kre 				 */
   1191   1.61  christos 				vforked = 0;
   1192   1.65  christos 				forkparent(jp, cmd, mode, pid);
   1193   1.61  christos 				goto parent;
   1194   1.61  christos 			}
   1195  1.140       kre 	VFORK_END
   1196   1.61  christos 		} else {
   1197  1.148       kre  normal_fork:
   1198   1.61  christos #endif
   1199   1.65  christos 			if (forkshell(jp, cmd, mode) != 0)
   1200   1.61  christos 				goto parent;	/* at end of routine */
   1201  1.174       kre 			CTRACE(DBG_PROCS|DBG_CMDS, ("Child sets EV_EXIT\n"));
   1202  1.159       kre 			flags |= EV_EXIT;
   1203   1.66  christos 			FORCEINTON;
   1204   1.61  christos #ifdef DO_SHAREDVFORK
   1205   1.61  christos 		}
   1206   1.61  christos #endif
   1207    1.1       cgd 		if (flags & EV_BACKCMD) {
   1208   1.61  christos 			if (!vforked) {
   1209   1.61  christos 				FORCEINTON;
   1210   1.61  christos 			}
   1211    1.1       cgd 			close(pip[0]);
   1212  1.120  christos 			movefd(pip[1], 1);
   1213    1.1       cgd 		}
   1214    1.1       cgd 		flags |= EV_EXIT;
   1215    1.1       cgd 	}
   1216    1.1       cgd 
   1217    1.1       cgd 	/* This is the child process if a fork occurred. */
   1218    1.1       cgd 	/* Execute the command. */
   1219   1.70       dsl 	switch (cmdentry.cmdtype) {
   1220  1.159       kre 		volatile int saved;
   1221  1.188       kre 		struct funcdef * volatile savefunc;
   1222  1.159       kre 
   1223   1.70       dsl 	case CMDFUNCTION:
   1224  1.152       kre 		VXTRACE(DBG_EVAL, ("Shell function%s:  ",vforked?" VF":""),
   1225  1.152       kre 		    trargs(argv));
   1226  1.159       kre 		redirect(cmd->ncmd.redirect, saved =
   1227  1.159       kre 			!(flags & EV_EXIT) || have_traps() ? REDIR_PUSH : 0);
   1228    1.1       cgd 		saveparam = shellparam;
   1229    1.1       cgd 		shellparam.malloc = 0;
   1230   1.32  christos 		shellparam.reset = 1;
   1231    1.1       cgd 		shellparam.nparam = argc - 1;
   1232    1.1       cgd 		shellparam.p = argv + 1;
   1233    1.1       cgd 		shellparam.optnext = NULL;
   1234    1.1       cgd 		INTOFF;
   1235    1.1       cgd 		savelocalvars = localvars;
   1236    1.1       cgd 		localvars = NULL;
   1237  1.188       kre 		reffunc(savefunc = cmdentry.u.func);
   1238    1.1       cgd 		INTON;
   1239    1.1       cgd 		if (setjmp(jmploc.loc)) {
   1240   1.47  christos 			if (exception == EXSHELLPROC) {
   1241   1.47  christos 				freeparam((volatile struct shparam *)
   1242   1.47  christos 				    &saveparam);
   1243   1.47  christos 			} else {
   1244    1.1       cgd 				freeparam(&shellparam);
   1245    1.1       cgd 				shellparam = saveparam;
   1246    1.1       cgd 			}
   1247  1.159       kre 			if (saved)
   1248  1.180   msaitoh 				popredir();
   1249  1.188       kre 			unreffunc(savefunc);
   1250    1.1       cgd 			poplocalvars();
   1251    1.1       cgd 			localvars = savelocalvars;
   1252  1.143       kre 			funclinebase = savefuncline;
   1253  1.143       kre 			funclineabs = savefuncabs;
   1254    1.1       cgd 			handler = savehandler;
   1255    1.1       cgd 			longjmp(handler->loc, 1);
   1256    1.1       cgd 		}
   1257    1.1       cgd 		savehandler = handler;
   1258    1.1       cgd 		handler = &jmploc;
   1259  1.143       kre 		if (cmdentry.u.func) {
   1260  1.143       kre 			if (cmdentry.lno_frel)
   1261  1.143       kre 				funclinebase = cmdentry.lineno - 1;
   1262  1.143       kre 			else
   1263  1.143       kre 				funclinebase = 0;
   1264  1.143       kre 			funclineabs = cmdentry.lineno;
   1265  1.143       kre 
   1266  1.143       kre 			VTRACE(DBG_EVAL,
   1267  1.143       kre 			  ("function: node: %d '%s' # %d%s; funclinebase=%d\n",
   1268  1.155       kre 			    getfuncnode(cmdentry.u.func)->type,
   1269  1.155       kre 			    NODETYPENAME(getfuncnode(cmdentry.u.func)->type),
   1270  1.143       kre 			    cmdentry.lineno, cmdentry.lno_frel?" (=1)":"",
   1271  1.143       kre 			    funclinebase));
   1272  1.143       kre 		}
   1273  1.167       kre 		listmklocal(varlist.list, VDOEXPORT | VEXPORT);
   1274   1.70       dsl 		/* stop shell blowing its stack */
   1275   1.70       dsl 		if (++funcnest > 1000)
   1276   1.70       dsl 			error("too many nested function calls");
   1277  1.159       kre 		evaltree(getfuncnode(cmdentry.u.func),
   1278  1.159       kre 		    flags & (EV_TESTED|EV_EXIT));
   1279    1.1       cgd 		funcnest--;
   1280    1.1       cgd 		INTOFF;
   1281  1.155       kre 		unreffunc(cmdentry.u.func);
   1282    1.1       cgd 		poplocalvars();
   1283    1.1       cgd 		localvars = savelocalvars;
   1284  1.143       kre 		funclinebase = savefuncline;
   1285  1.143       kre 		funclineabs = savefuncabs;
   1286    1.1       cgd 		freeparam(&shellparam);
   1287    1.1       cgd 		shellparam = saveparam;
   1288    1.1       cgd 		handler = savehandler;
   1289  1.159       kre 		if (saved)
   1290  1.159       kre 			popredir();
   1291    1.1       cgd 		INTON;
   1292    1.1       cgd 		if (evalskip == SKIPFUNC) {
   1293  1.109  christos 			evalskip = SKIPNONE;
   1294    1.1       cgd 			skipcount = 0;
   1295    1.1       cgd 		}
   1296    1.1       cgd 		if (flags & EV_EXIT)
   1297    1.1       cgd 			exitshell(exitstatus);
   1298   1.70       dsl 		break;
   1299   1.70       dsl 
   1300  1.164       kre 	case CMDSPLBLTIN:
   1301  1.164       kre 		VTRACE(DBG_EVAL, ("special "));
   1302   1.70       dsl 	case CMDBUILTIN:
   1303  1.164       kre 		VXTRACE(DBG_EVAL, ("builtin command [%d]%s:  ", argc,
   1304  1.164       kre 		    vforked ? " VF" : ""), trargs(argv));
   1305   1.68  christos 		mode = (cmdentry.u.bltin == execcmd) ? 0 : REDIR_PUSH;
   1306    1.1       cgd 		if (flags == EV_BACKCMD) {
   1307    1.1       cgd 			memout.nleft = 0;
   1308    1.1       cgd 			memout.nextc = memout.buf;
   1309    1.1       cgd 			memout.bufsize = 64;
   1310    1.1       cgd 			mode |= REDIR_BACKQ;
   1311    1.1       cgd 		}
   1312   1.70       dsl 		e = -1;
   1313  1.169       kre 		savecmdname = commandname;
   1314  1.169       kre 		savetopfile = getcurrentfile();
   1315   1.68  christos 		savehandler = handler;
   1316  1.104     joerg 		temp_path = 0;
   1317   1.68  christos 		if (!setjmp(jmploc.loc)) {
   1318  1.169       kre 			handler = &jmploc;
   1319  1.169       kre 
   1320  1.148       kre 			/*
   1321  1.148       kre 			 * We need to ensure the command hash table isn't
   1322  1.130  christos 			 * corrupted by temporary PATH assignments.
   1323   1.70       dsl 			 * However we must ensure the 'local' command works!
   1324   1.70       dsl 			 */
   1325   1.70       dsl 			if (path != pathval() && (cmdentry.u.bltin == hashcmd ||
   1326   1.70       dsl 			    cmdentry.u.bltin == typecmd)) {
   1327   1.70       dsl 				savelocalvars = localvars;
   1328   1.70       dsl 				localvars = 0;
   1329  1.104     joerg 				temp_path = 1;
   1330   1.70       dsl 				mklocal(path - 5 /* PATH= */, 0);
   1331  1.104     joerg 			}
   1332   1.68  christos 			redirect(cmd->ncmd.redirect, mode);
   1333   1.68  christos 
   1334  1.164       kre 			/*
   1335  1.164       kre 			 * the empty command is regarded as a normal
   1336  1.164       kre 			 * builtin for the purposes of redirects, but
   1337  1.164       kre 			 * is a special builtin for var assigns.
   1338  1.164       kre 			 * (unless we are the "command" command.)
   1339  1.164       kre 			 */
   1340  1.164       kre 			if (argc == 0 && !(cmd_flags & DO_NOFUNC))
   1341  1.164       kre 				cmdentry.cmdtype = CMDSPLBLTIN;
   1342  1.164       kre 
   1343   1.68  christos 			/* exec is a special builtin, but needs this list... */
   1344   1.68  christos 			cmdenviron = varlist.list;
   1345   1.68  christos 			/* we must check 'readonly' flag for all builtins */
   1346   1.68  christos 			listsetvar(varlist.list,
   1347   1.68  christos 				cmdentry.cmdtype == CMDSPLBLTIN ? 0 : VNOSET);
   1348   1.68  christos 			commandname = argv[0];
   1349   1.68  christos 			/* initialize nextopt */
   1350   1.68  christos 			argptr = argv + 1;
   1351   1.68  christos 			optptr = NULL;
   1352   1.68  christos 			/* and getopt */
   1353   1.68  christos 			optreset = 1;
   1354   1.68  christos 			optind = 1;
   1355  1.103  christos 			builtin_flags = flags;
   1356  1.185       kre 			clr_err(out1);	/* discard previous I/O errors */
   1357   1.68  christos 			exitstatus = cmdentry.u.bltin(argc, argv);
   1358   1.68  christos 		} else {
   1359    1.1       cgd 			e = exception;
   1360  1.159       kre 			if (e == EXINT)
   1361  1.159       kre 				exitstatus = SIGINT + 128;
   1362  1.159       kre 			else if (e == EXEXEC)
   1363  1.159       kre 				exitstatus = exerrno;
   1364  1.159       kre 			else if (e != EXEXIT)
   1365  1.159       kre 				exitstatus = 2;
   1366    1.1       cgd 		}
   1367   1.70       dsl 		handler = savehandler;
   1368    1.1       cgd 		flushall();
   1369    1.1       cgd 		out1 = &output;
   1370    1.1       cgd 		out2 = &errout;
   1371    1.1       cgd 		freestdout();
   1372   1.70       dsl 		if (temp_path) {
   1373   1.70       dsl 			poplocalvars();
   1374   1.70       dsl 			localvars = savelocalvars;
   1375   1.70       dsl 		}
   1376   1.39   thorpej 		cmdenviron = NULL;
   1377    1.1       cgd 		if (e != EXSHELLPROC) {
   1378    1.1       cgd 			commandname = savecmdname;
   1379   1.44   mycroft 			if (flags & EV_EXIT)
   1380    1.1       cgd 				exitshell(exitstatus);
   1381    1.1       cgd 		}
   1382    1.1       cgd 		if (e != -1) {
   1383   1.31  christos 			if ((e != EXERROR && e != EXEXEC)
   1384   1.70       dsl 			    || cmdentry.cmdtype == CMDSPLBLTIN)
   1385    1.1       cgd 				exraise(e);
   1386  1.169       kre 			popfilesupto(savetopfile);
   1387    1.1       cgd 			FORCEINTON;
   1388    1.1       cgd 		}
   1389   1.68  christos 		if (cmdentry.u.bltin != execcmd)
   1390    1.1       cgd 			popredir();
   1391    1.1       cgd 		if (flags == EV_BACKCMD) {
   1392    1.1       cgd 			backcmd->buf = memout.buf;
   1393    1.1       cgd 			backcmd->nleft = memout.nextc - memout.buf;
   1394    1.1       cgd 			memout.buf = NULL;
   1395    1.1       cgd 		}
   1396   1.70       dsl 		break;
   1397   1.70       dsl 
   1398   1.70       dsl 	default:
   1399  1.152       kre 		VXTRACE(DBG_EVAL, ("normal command%s:  ", vforked?" VF":""),
   1400  1.152       kre 		    trargs(argv));
   1401  1.117  christos 		redirect(cmd->ncmd.redirect,
   1402  1.117  christos 		    (vforked ? REDIR_VFORK : 0) | REDIR_KEEP);
   1403   1.61  christos 		if (!vforked)
   1404   1.61  christos 			for (sp = varlist.list ; sp ; sp = sp->next)
   1405  1.167       kre 				setvareq(sp->text, VDOEXPORT|VEXPORT|VSTACK);
   1406    1.1       cgd 		envp = environment();
   1407   1.70       dsl 		shellexec(argv, envp, path, cmdentry.u.index, vforked);
   1408   1.70       dsl 		break;
   1409    1.1       cgd 	}
   1410    1.1       cgd 	goto out;
   1411    1.1       cgd 
   1412  1.148       kre  parent:			/* parent process gets here (if we forked) */
   1413  1.148       kre 
   1414  1.113  christos 	exitstatus = 0;		/* if not altered just below */
   1415   1.68  christos 	if (mode == FORK_FG) {	/* argument to fork */
   1416    1.1       cgd 		exitstatus = waitforjob(jp);
   1417   1.68  christos 	} else if (mode == FORK_NOJOB) {
   1418    1.1       cgd 		backcmd->fd = pip[0];
   1419    1.1       cgd 		close(pip[1]);
   1420    1.1       cgd 		backcmd->jp = jp;
   1421    1.1       cgd 	}
   1422   1.66  christos 	FORCEINTON;
   1423    1.1       cgd 
   1424  1.148       kre  out:
   1425    1.1       cgd 	if (lastarg)
   1426  1.132       kre 		/* implement $_ for whatever use that really is */
   1427  1.147       kre 		(void) setvarsafe("_", lastarg, VNOERROR);
   1428    1.1       cgd 	popstackmark(&smark);
   1429    1.1       cgd }
   1430    1.1       cgd 
   1431    1.1       cgd 
   1432    1.1       cgd /*
   1433    1.1       cgd  * Search for a command.  This is called before we fork so that the
   1434    1.1       cgd  * location of the command will be available in the parent as well as
   1435    1.1       cgd  * the child.  The check for "goodname" is an overly conservative
   1436    1.1       cgd  * check that the name will not be subject to expansion.
   1437    1.1       cgd  */
   1438    1.1       cgd 
   1439    1.1       cgd STATIC void
   1440   1.68  christos prehash(union node *n)
   1441   1.22  christos {
   1442    1.1       cgd 	struct cmdentry entry;
   1443    1.1       cgd 
   1444   1.86  christos 	if (n && n->type == NCMD && n->ncmd.args)
   1445   1.15   mycroft 		if (goodname(n->ncmd.args->narg.text))
   1446   1.26  christos 			find_command(n->ncmd.args->narg.text, &entry, 0,
   1447   1.26  christos 				     pathval());
   1448    1.1       cgd }
   1449    1.1       cgd 
   1450  1.122       kre int
   1451  1.109  christos in_function(void)
   1452  1.109  christos {
   1453  1.109  christos 	return funcnest;
   1454  1.109  christos }
   1455    1.1       cgd 
   1456  1.122       kre enum skipstate
   1457  1.109  christos current_skipstate(void)
   1458  1.109  christos {
   1459  1.109  christos 	return evalskip;
   1460  1.109  christos }
   1461  1.109  christos 
   1462  1.122       kre void
   1463  1.168       kre save_skipstate(struct skipsave *p)
   1464  1.168       kre {
   1465  1.168       kre 	*p = s_k_i_p;
   1466  1.168       kre }
   1467  1.168       kre 
   1468  1.168       kre void
   1469  1.168       kre restore_skipstate(const struct skipsave *p)
   1470  1.168       kre {
   1471  1.168       kre 	s_k_i_p = *p;
   1472  1.168       kre }
   1473  1.168       kre 
   1474  1.168       kre void
   1475  1.109  christos stop_skipping(void)
   1476  1.109  christos {
   1477  1.109  christos 	evalskip = SKIPNONE;
   1478  1.109  christos 	skipcount = 0;
   1479  1.109  christos }
   1480    1.1       cgd 
   1481    1.1       cgd /*
   1482    1.1       cgd  * Builtin commands.  Builtin commands whose functions are closely
   1483    1.1       cgd  * tied to evaluation are implemented here.
   1484    1.1       cgd  */
   1485    1.1       cgd 
   1486    1.1       cgd /*
   1487   1.70       dsl  * No command given.
   1488    1.1       cgd  */
   1489    1.1       cgd 
   1490   1.16       cgd int
   1491   1.68  christos bltincmd(int argc, char **argv)
   1492   1.16       cgd {
   1493   1.31  christos 	/*
   1494   1.22  christos 	 * Preserve exitstatus of a previous possible redirection
   1495   1.31  christos 	 * as POSIX mandates
   1496   1.22  christos 	 */
   1497   1.68  christos 	return back_exitstatus;
   1498    1.1       cgd }
   1499    1.1       cgd 
   1500    1.1       cgd 
   1501    1.1       cgd /*
   1502    1.1       cgd  * Handle break and continue commands.  Break, continue, and return are
   1503    1.1       cgd  * all handled by setting the evalskip flag.  The evaluation routines
   1504    1.1       cgd  * above all check this flag, and if it is set they start skipping
   1505    1.1       cgd  * commands rather than executing them.  The variable skipcount is
   1506    1.1       cgd  * the number of loops to break/continue, or the number of function
   1507    1.1       cgd  * levels to return.  (The latter is always 1.)  It should probably
   1508    1.1       cgd  * be an error to break out of more loops than exist, but it isn't
   1509    1.1       cgd  * in the standard shell so we don't make it one here.
   1510    1.1       cgd  */
   1511    1.1       cgd 
   1512   1.16       cgd int
   1513   1.68  christos breakcmd(int argc, char **argv)
   1514   1.16       cgd {
   1515   1.30  christos 	int n = argc > 1 ? number(argv[1]) : 1;
   1516    1.1       cgd 
   1517  1.135       kre 	if (n <= 0)
   1518  1.135       kre 		error("invalid count: %d", n);
   1519    1.1       cgd 	if (n > loopnest)
   1520    1.1       cgd 		n = loopnest;
   1521    1.1       cgd 	if (n > 0) {
   1522    1.1       cgd 		evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK;
   1523    1.1       cgd 		skipcount = n;
   1524    1.1       cgd 	}
   1525    1.1       cgd 	return 0;
   1526    1.1       cgd }
   1527    1.1       cgd 
   1528  1.109  christos int
   1529  1.109  christos dotcmd(int argc, char **argv)
   1530  1.109  christos {
   1531  1.109  christos 	exitstatus = 0;
   1532  1.109  christos 
   1533  1.178       kre 	(void) nextopt(NULL);		/* ignore a leading "--" */
   1534  1.178       kre 
   1535  1.178       kre 	if (*argptr != NULL) {		/* That's what SVR2 does */
   1536  1.109  christos 		char *fullname;
   1537  1.109  christos 		/*
   1538  1.109  christos 		 * dot_funcnest needs to be 0 when not in a dotcmd, so it
   1539  1.109  christos 		 * cannot be restored with (funcnest + 1).
   1540  1.109  christos 		 */
   1541  1.109  christos 		int dot_funcnest_old;
   1542  1.109  christos 		struct stackmark smark;
   1543  1.109  christos 
   1544  1.109  christos 		setstackmark(&smark);
   1545  1.178       kre 		fullname = find_dot_file(*argptr);
   1546  1.109  christos 		setinputfile(fullname, 1);
   1547  1.109  christos 		commandname = fullname;
   1548  1.109  christos 		dot_funcnest_old = dot_funcnest;
   1549  1.109  christos 		dot_funcnest = funcnest + 1;
   1550  1.109  christos 		cmdloop(0);
   1551  1.109  christos 		dot_funcnest = dot_funcnest_old;
   1552  1.109  christos 		popfile();
   1553  1.109  christos 		popstackmark(&smark);
   1554  1.109  christos 	}
   1555  1.109  christos 	return exitstatus;
   1556  1.109  christos }
   1557  1.109  christos 
   1558  1.109  christos /*
   1559  1.171       kre  * allow dotfile function nesting to be manipulated
   1560  1.171       kre  * (for read_profile).  This allows profile files to
   1561  1.171       kre  * be treated as if they were used as '.' commands,
   1562  1.171       kre  * (approximately) and in particular, for "return" to work.
   1563  1.171       kre  */
   1564  1.171       kre int
   1565  1.171       kre set_dot_funcnest(int new)
   1566  1.171       kre {
   1567  1.171       kre 	int rv = dot_funcnest;
   1568  1.171       kre 
   1569  1.171       kre 	if (new >= 0)
   1570  1.171       kre 		dot_funcnest = new;
   1571  1.171       kre 
   1572  1.171       kre 	return rv;
   1573  1.171       kre }
   1574  1.171       kre 
   1575  1.171       kre /*
   1576  1.109  christos  * Take commands from a file.  To be compatible we should do a path
   1577  1.109  christos  * search for the file, which is necessary to find sub-commands.
   1578  1.109  christos  */
   1579  1.109  christos 
   1580  1.109  christos STATIC char *
   1581  1.109  christos find_dot_file(char *basename)
   1582  1.109  christos {
   1583  1.109  christos 	char *fullname;
   1584  1.109  christos 	const char *path = pathval();
   1585  1.109  christos 	struct stat statb;
   1586  1.109  christos 
   1587  1.109  christos 	/* don't try this for absolute or relative paths */
   1588  1.121       kre 	if (strchr(basename, '/')) {
   1589  1.121       kre 		if (stat(basename, &statb) == 0) {
   1590  1.128       kre 			if (S_ISDIR(statb.st_mode))
   1591  1.128       kre 				error("%s: is a directory", basename);
   1592  1.128       kre 			if (S_ISBLK(statb.st_mode))
   1593  1.128       kre 				error("%s: is a block device", basename);
   1594  1.128       kre 			return basename;
   1595  1.121       kre 		}
   1596  1.141       kre 	} else while ((fullname = padvance(&path, basename, 1)) != NULL) {
   1597  1.128       kre 		if ((stat(fullname, &statb) == 0)) {
   1598  1.128       kre 			/* weird format is to ease future code... */
   1599  1.128       kre 			if (S_ISDIR(statb.st_mode) || S_ISBLK(statb.st_mode))
   1600  1.128       kre 				;
   1601  1.128       kre #if notyet
   1602  1.128       kre 			else if (unreadable()) {
   1603  1.128       kre 				/*
   1604  1.128       kre 				 * testing this via st_mode is ugly to get
   1605  1.128       kre 				 * correct (and would ignore ACLs).
   1606  1.128       kre 				 * better way is just to open the file.
   1607  1.128       kre 				 * But doing that here would (currently)
   1608  1.128       kre 				 * mean opening the file twice, which
   1609  1.128       kre 				 * might not be safe.  So, defer this
   1610  1.128       kre 				 * test until code is restructures so
   1611  1.128       kre 				 * we can return a fd.   Then we also
   1612  1.128       kre 				 * get to fix the mem leak just below...
   1613  1.128       kre 				 */
   1614  1.128       kre 			}
   1615  1.128       kre #endif
   1616  1.128       kre 			else {
   1617  1.128       kre 				/*
   1618  1.128       kre 				 * Don't bother freeing here, since
   1619  1.128       kre 				 * it will be freed by the caller.
   1620  1.128       kre 				 * XXX no it won't - a bug for later.
   1621  1.128       kre 				 */
   1622  1.128       kre 				return fullname;
   1623  1.128       kre 			}
   1624  1.109  christos 		}
   1625  1.109  christos 		stunalloc(fullname);
   1626  1.109  christos 	}
   1627  1.109  christos 
   1628  1.109  christos 	/* not found in the PATH */
   1629  1.109  christos 	error("%s: not found", basename);
   1630  1.109  christos 	/* NOTREACHED */
   1631  1.109  christos }
   1632  1.109  christos 
   1633  1.109  christos 
   1634    1.1       cgd 
   1635    1.1       cgd /*
   1636    1.1       cgd  * The return command.
   1637  1.109  christos  *
   1638  1.109  christos  * Quoth the POSIX standard:
   1639  1.109  christos  *   The return utility shall cause the shell to stop executing the current
   1640  1.109  christos  *   function or dot script. If the shell is not currently executing
   1641  1.109  christos  *   a function or dot script, the results are unspecified.
   1642  1.109  christos  *
   1643  1.109  christos  * As for the unspecified part, there seems to be no de-facto standard: bash
   1644  1.109  christos  * ignores the return with a warning, zsh ignores the return in interactive
   1645  1.109  christos  * mode but seems to liken it to exit in a script.  (checked May 2014)
   1646  1.109  christos  *
   1647  1.109  christos  * We choose to silently ignore the return.  Older versions of this shell
   1648  1.109  christos  * set evalskip to SKIPFILE causing the shell to (indirectly) exit.  This
   1649  1.109  christos  * had at least the problem of circumventing the check for stopped jobs,
   1650  1.109  christos  * which would occur for exit or ^D.
   1651    1.1       cgd  */
   1652    1.1       cgd 
   1653   1.16       cgd int
   1654   1.68  christos returncmd(int argc, char **argv)
   1655   1.16       cgd {
   1656   1.68  christos 	int ret = argc > 1 ? number(argv[1]) : exitstatus;
   1657    1.1       cgd 
   1658  1.109  christos 	if ((dot_funcnest == 0 && funcnest)
   1659  1.109  christos 	    || (dot_funcnest > 0 && funcnest - (dot_funcnest - 1) > 0)) {
   1660    1.1       cgd 		evalskip = SKIPFUNC;
   1661    1.1       cgd 		skipcount = 1;
   1662  1.109  christos 	} else if (dot_funcnest > 0) {
   1663   1.27  christos 		evalskip = SKIPFILE;
   1664   1.27  christos 		skipcount = 1;
   1665  1.109  christos 	} else {
   1666  1.109  christos 		/* XXX: should a warning be issued? */
   1667  1.109  christos 		ret = 0;
   1668    1.1       cgd 	}
   1669  1.109  christos 
   1670  1.109  christos 	return ret;
   1671    1.1       cgd }
   1672    1.1       cgd 
   1673    1.1       cgd 
   1674   1.16       cgd int
   1675   1.68  christos falsecmd(int argc, char **argv)
   1676   1.16       cgd {
   1677    1.8       jtc 	return 1;
   1678    1.8       jtc }
   1679    1.8       jtc 
   1680    1.8       jtc 
   1681   1.16       cgd int
   1682   1.68  christos truecmd(int argc, char **argv)
   1683   1.16       cgd {
   1684    1.1       cgd 	return 0;
   1685    1.1       cgd }
   1686    1.1       cgd 
   1687    1.1       cgd 
   1688   1.16       cgd int
   1689   1.68  christos execcmd(int argc, char **argv)
   1690   1.16       cgd {
   1691  1.178       kre 	(void) nextopt(NULL);		/* ignore a leading "--" */
   1692  1.178       kre 
   1693  1.178       kre 	if (*argptr) {
   1694   1.20  christos 		struct strlist *sp;
   1695   1.20  christos 
   1696    1.1       cgd 		iflag = 0;		/* exit on error */
   1697    1.7       jtc 		mflag = 0;
   1698    1.7       jtc 		optschanged();
   1699   1.70       dsl 		for (sp = cmdenviron; sp; sp = sp->next)
   1700  1.167       kre 			setvareq(sp->text, VDOEXPORT|VEXPORT|VSTACK);
   1701  1.178       kre 		shellexec(argptr, environment(), pathval(), 0, 0);
   1702    1.1       cgd 	}
   1703   1.68  christos 	return 0;
   1704   1.68  christos }
   1705   1.68  christos 
   1706   1.68  christos static int
   1707   1.73    itojun conv_time(clock_t ticks, char *seconds, size_t l)
   1708   1.68  christos {
   1709   1.68  christos 	static clock_t tpm = 0;
   1710   1.68  christos 	clock_t mins;
   1711   1.68  christos 	int i;
   1712   1.68  christos 
   1713   1.68  christos 	if (!tpm)
   1714   1.68  christos 		tpm = sysconf(_SC_CLK_TCK) * 60;
   1715   1.68  christos 
   1716   1.68  christos 	mins = ticks / tpm;
   1717   1.73    itojun 	snprintf(seconds, l, "%.4f", (ticks - mins * tpm) * 60.0 / tpm );
   1718   1.68  christos 
   1719   1.68  christos 	if (seconds[0] == '6' && seconds[1] == '0') {
   1720   1.68  christos 		/* 59.99995 got rounded up... */
   1721   1.68  christos 		mins++;
   1722   1.73    itojun 		strlcpy(seconds, "0.0", l);
   1723   1.68  christos 		return mins;
   1724   1.68  christos 	}
   1725   1.68  christos 
   1726   1.68  christos 	/* suppress trailing zeros */
   1727   1.68  christos 	i = strlen(seconds) - 1;
   1728   1.68  christos 	for (; seconds[i] == '0' && seconds[i - 1] != '.'; i--)
   1729   1.68  christos 		seconds[i] = 0;
   1730   1.68  christos 	return mins;
   1731   1.68  christos }
   1732   1.68  christos 
   1733   1.68  christos int
   1734   1.68  christos timescmd(int argc, char **argv)
   1735   1.68  christos {
   1736   1.68  christos 	struct tms tms;
   1737   1.68  christos 	int u, s, cu, cs;
   1738   1.68  christos 	char us[8], ss[8], cus[8], css[8];
   1739   1.68  christos 
   1740   1.68  christos 	nextopt("");
   1741   1.68  christos 
   1742   1.68  christos 	times(&tms);
   1743   1.68  christos 
   1744   1.73    itojun 	u = conv_time(tms.tms_utime, us, sizeof(us));
   1745   1.73    itojun 	s = conv_time(tms.tms_stime, ss, sizeof(ss));
   1746   1.73    itojun 	cu = conv_time(tms.tms_cutime, cus, sizeof(cus));
   1747   1.73    itojun 	cs = conv_time(tms.tms_cstime, css, sizeof(css));
   1748   1.68  christos 
   1749   1.68  christos 	outfmt(out1, "%dm%ss %dm%ss\n%dm%ss %dm%ss\n",
   1750   1.68  christos 		u, us, s, ss, cu, cus, cs, css);
   1751   1.68  christos 
   1752    1.1       cgd 	return 0;
   1753    1.1       cgd }
   1754