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main.c revision 1.57.8.1 
      1 /*	$NetBSD: main.c,v 1.57.8.1 2014/08/19 23:45:11 tls Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1991, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This code is derived from software contributed to Berkeley by
      8  * Kenneth Almquist.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. Neither the name of the University nor the names of its contributors
     19  *    may be used to endorse or promote products derived from this software
     20  *    without specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32  * SUCH DAMAGE.
     33  */
     34 
     35 #include <sys/cdefs.h>
     36 #ifndef lint
     37 __COPYRIGHT("@(#) Copyright (c) 1991, 1993\
     38  The Regents of the University of California.  All rights reserved.");
     39 #endif /* not lint */
     40 
     41 #ifndef lint
     42 #if 0
     43 static char sccsid[] = "@(#)main.c	8.7 (Berkeley) 7/19/95";
     44 #else
     45 __RCSID("$NetBSD: main.c,v 1.57.8.1 2014/08/19 23:45:11 tls Exp $");
     46 #endif
     47 #endif /* not lint */
     48 
     49 #include <errno.h>
     50 #include <stdio.h>
     51 #include <signal.h>
     52 #include <sys/stat.h>
     53 #include <unistd.h>
     54 #include <stdlib.h>
     55 #include <locale.h>
     56 #include <fcntl.h>
     57 
     58 
     59 #include "shell.h"
     60 #include "main.h"
     61 #include "mail.h"
     62 #include "options.h"
     63 #include "builtins.h"
     64 #include "output.h"
     65 #include "parser.h"
     66 #include "nodes.h"
     67 #include "expand.h"
     68 #include "eval.h"
     69 #include "jobs.h"
     70 #include "input.h"
     71 #include "trap.h"
     72 #include "var.h"
     73 #include "show.h"
     74 #include "memalloc.h"
     75 #include "error.h"
     76 #include "init.h"
     77 #include "mystring.h"
     78 #include "exec.h"
     79 #include "cd.h"
     80 
     81 #define PROFILE 0
     82 
     83 int rootpid;
     84 int rootshell;
     85 int posix;
     86 #if PROFILE
     87 short profile_buf[16384];
     88 extern int etext();
     89 #endif
     90 
     91 STATIC void read_profile(const char *);
     92 int main(int, char **);
     93 
     94 /*
     95  * Main routine.  We initialize things, parse the arguments, execute
     96  * profiles if we're a login shell, and then call cmdloop to execute
     97  * commands.  The setjmp call sets up the location to jump to when an
     98  * exception occurs.  When an exception occurs the variable "state"
     99  * is used to figure out how far we had gotten.
    100  */
    101 
    102 int
    103 main(int argc, char **argv)
    104 {
    105 	struct jmploc jmploc;
    106 	struct stackmark smark;
    107 	volatile int state;
    108 	char *shinit;
    109 
    110 	setlocale(LC_ALL, "");
    111 
    112 	posix = getenv("POSIXLY_CORRECT") != NULL;
    113 #if PROFILE
    114 	monitor(4, etext, profile_buf, sizeof profile_buf, 50);
    115 #endif
    116 	state = 0;
    117 	if (setjmp(jmploc.loc)) {
    118 		/*
    119 		 * When a shell procedure is executed, we raise the
    120 		 * exception EXSHELLPROC to clean up before executing
    121 		 * the shell procedure.
    122 		 */
    123 		switch (exception) {
    124 		case EXSHELLPROC:
    125 			rootpid = getpid();
    126 			rootshell = 1;
    127 			minusc = NULL;
    128 			state = 3;
    129 			break;
    130 
    131 		case EXEXEC:
    132 			exitstatus = exerrno;
    133 			break;
    134 
    135 		case EXERROR:
    136 			exitstatus = 2;
    137 			break;
    138 
    139 		default:
    140 			break;
    141 		}
    142 
    143 		if (exception != EXSHELLPROC) {
    144 			if (state == 0 || iflag == 0 || ! rootshell)
    145 				exitshell(exitstatus);
    146 		}
    147 		reset();
    148 		if (exception == EXINT
    149 #if ATTY
    150 		 && (! attyset() || equal(termval(), "emacs"))
    151 #endif
    152 		 ) {
    153 			out2c('\n');
    154 			flushout(&errout);
    155 		}
    156 		popstackmark(&smark);
    157 		FORCEINTON;				/* enable interrupts */
    158 		if (state == 1)
    159 			goto state1;
    160 		else if (state == 2)
    161 			goto state2;
    162 		else if (state == 3)
    163 			goto state3;
    164 		else
    165 			goto state4;
    166 	}
    167 	handler = &jmploc;
    168 #ifdef DEBUG
    169 #if DEBUG == 2
    170 	debug = 1;
    171 #endif
    172 	opentrace();
    173 	trputs("Shell args:  ");  trargs(argv);
    174 #endif
    175 	rootpid = getpid();
    176 	rootshell = 1;
    177 	init();
    178 	initpwd();
    179 	setstackmark(&smark);
    180 	procargs(argc, argv);
    181 	if (argv[0] && argv[0][0] == '-') {
    182 		state = 1;
    183 		read_profile("/etc/profile");
    184 state1:
    185 		state = 2;
    186 		read_profile(".profile");
    187 	}
    188 state2:
    189 	state = 3;
    190 	if ((iflag || !posix) &&
    191 	    getuid() == geteuid() && getgid() == getegid()) {
    192 		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
    193 			state = 3;
    194 			read_profile(shinit);
    195 		}
    196 	}
    197 state3:
    198 	state = 4;
    199 	if (sflag == 0 || minusc) {
    200 		static int sigs[] =  {
    201 		    SIGINT, SIGQUIT, SIGHUP,
    202 #ifdef SIGTSTP
    203 		    SIGTSTP,
    204 #endif
    205 		    SIGPIPE
    206 		};
    207 #define SIGSSIZE (sizeof(sigs)/sizeof(sigs[0]))
    208 		size_t i;
    209 
    210 		for (i = 0; i < SIGSSIZE; i++)
    211 		    setsignal(sigs[i], 0);
    212 	}
    213 
    214 	if (minusc)
    215 		evalstring(minusc, 0);
    216 
    217 	if (sflag || minusc == NULL) {
    218 state4:	/* XXX ??? - why isn't this before the "if" statement */
    219 		cmdloop(1);
    220 	}
    221 #if PROFILE
    222 	monitor(0);
    223 #endif
    224 	exitshell(exitstatus);
    225 	/* NOTREACHED */
    226 }
    227 
    228 
    229 /*
    230  * Read and execute commands.  "Top" is nonzero for the top level command
    231  * loop; it turns on prompting if the shell is interactive.
    232  */
    233 
    234 void
    235 cmdloop(int top)
    236 {
    237 	union node *n;
    238 	struct stackmark smark;
    239 	int inter;
    240 	int numeof = 0;
    241 	enum skipstate skip;
    242 
    243 	TRACE(("cmdloop(%d) called\n", top));
    244 	setstackmark(&smark);
    245 	for (;;) {
    246 		if (pendingsigs)
    247 			dotrap();
    248 		inter = 0;
    249 		if (iflag == 1 && top) {
    250 			inter = 1;
    251 			showjobs(out2, SHOW_CHANGED);
    252 			chkmail(0);
    253 			flushout(&errout);
    254 		}
    255 		n = parsecmd(inter);
    256 		/* showtree(n); DEBUG */
    257 		if (n == NEOF) {
    258 			if (!top || numeof >= 50)
    259 				break;
    260 			if (!stoppedjobs()) {
    261 				if (!Iflag)
    262 					break;
    263 				out2str("\nUse \"exit\" to leave shell.\n");
    264 			}
    265 			numeof++;
    266 		} else if (n != NULL && nflag == 0) {
    267 			job_warning = (job_warning == 2) ? 1 : 0;
    268 			numeof = 0;
    269 			evaltree(n, 0);
    270 		}
    271 		popstackmark(&smark);
    272 		setstackmark(&smark);
    273 
    274 		/*
    275 		 * Any SKIP* can occur here!  SKIP(FUNC|BREAK|CONT) occur when
    276 		 * a dotcmd is in a loop or a function body and appropriate
    277 		 * built-ins occurs in file scope in the sourced file.  Values
    278 		 * other than SKIPFILE are reset by the appropriate eval*()
    279 		 * that contained the dotcmd() call.
    280 		 */
    281 		skip = current_skipstate();
    282 		if (skip != SKIPNONE) {
    283 			if (skip == SKIPFILE)
    284 				stop_skipping();
    285 			break;
    286 		}
    287 	}
    288 	popstackmark(&smark);
    289 }
    290 
    291 
    292 
    293 /*
    294  * Read /etc/profile or .profile.  Return on error.
    295  */
    296 
    297 STATIC void
    298 read_profile(const char *name)
    299 {
    300 	int fd;
    301 	int xflag_set = 0;
    302 	int vflag_set = 0;
    303 
    304 	INTOFF;
    305 	if ((fd = open(name, O_RDONLY)) >= 0)
    306 		setinputfd(fd, 1);
    307 	INTON;
    308 	if (fd < 0)
    309 		return;
    310 	/* -q turns off -x and -v just when executing init files */
    311 	if (qflag)  {
    312 	    if (xflag)
    313 		    xflag = 0, xflag_set = 1;
    314 	    if (vflag)
    315 		    vflag = 0, vflag_set = 1;
    316 	}
    317 	cmdloop(0);
    318 	if (qflag)  {
    319 	    if (xflag_set)
    320 		    xflag = 1;
    321 	    if (vflag_set)
    322 		    vflag = 1;
    323 	}
    324 	popfile();
    325 }
    326 
    327 
    328 
    329 /*
    330  * Read a file containing shell functions.
    331  */
    332 
    333 void
    334 readcmdfile(char *name)
    335 {
    336 	int fd;
    337 
    338 	INTOFF;
    339 	if ((fd = open(name, O_RDONLY)) >= 0)
    340 		setinputfd(fd, 1);
    341 	else
    342 		error("Can't open %s", name);
    343 	INTON;
    344 	cmdloop(0);
    345 	popfile();
    346 }
    347 
    348 
    349 
    350 int
    351 exitcmd(int argc, char **argv)
    352 {
    353 	if (stoppedjobs())
    354 		return 0;
    355 	if (argc > 1)
    356 		exitstatus = number(argv[1]);
    357 	exitshell(exitstatus);
    358 	/* NOTREACHED */
    359 }
    360