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main.c revision 1.47 
      1 /*	$NetBSD: main.c,v 1.47 2003/08/07 09:05:34 agc 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\n\
     38 	The Regents of the University of California.  All rights reserved.\n");
     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 1.47 2003/08/07 09:05:34 agc 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 <locale.h>
     55 #include <fcntl.h>
     56 
     57 
     58 #include "shell.h"
     59 #include "main.h"
     60 #include "mail.h"
     61 #include "options.h"
     62 #include "output.h"
     63 #include "parser.h"
     64 #include "nodes.h"
     65 #include "expand.h"
     66 #include "eval.h"
     67 #include "jobs.h"
     68 #include "input.h"
     69 #include "trap.h"
     70 #include "var.h"
     71 #include "show.h"
     72 #include "memalloc.h"
     73 #include "error.h"
     74 #include "init.h"
     75 #include "mystring.h"
     76 #include "exec.h"
     77 #include "cd.h"
     78 
     79 #define PROFILE 0
     80 
     81 int rootpid;
     82 int rootshell;
     83 STATIC union node *curcmd;
     84 STATIC union node *prevcmd;
     85 #if PROFILE
     86 short profile_buf[16384];
     87 extern int etext();
     88 #endif
     89 
     90 STATIC void read_profile(const char *);
     91 STATIC char *find_dot_file(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 #if PROFILE
    113 	monitor(4, etext, profile_buf, sizeof profile_buf, 50);
    114 #endif
    115 	state = 0;
    116 	if (setjmp(jmploc.loc)) {
    117 		/*
    118 		 * When a shell procedure is executed, we raise the
    119 		 * exception EXSHELLPROC to clean up before executing
    120 		 * the shell procedure.
    121 		 */
    122 		switch (exception) {
    123 		case EXSHELLPROC:
    124 			rootpid = getpid();
    125 			rootshell = 1;
    126 			minusc = NULL;
    127 			state = 3;
    128 			break;
    129 
    130 		case EXEXEC:
    131 			exitstatus = exerrno;
    132 			break;
    133 
    134 		case EXERROR:
    135 			exitstatus = 2;
    136 			break;
    137 
    138 		default:
    139 			break;
    140 		}
    141 
    142 		if (exception != EXSHELLPROC) {
    143 			if (state == 0 || iflag == 0 || ! rootshell)
    144 				exitshell(exitstatus);
    145 		}
    146 		reset();
    147 		if (exception == EXINT
    148 #if ATTY
    149 		 && (! attyset() || equal(termval(), "emacs"))
    150 #endif
    151 		 ) {
    152 			out2c('\n');
    153 			flushout(&errout);
    154 		}
    155 		popstackmark(&smark);
    156 		FORCEINTON;				/* enable interrupts */
    157 		if (state == 1)
    158 			goto state1;
    159 		else if (state == 2)
    160 			goto state2;
    161 		else if (state == 3)
    162 			goto state3;
    163 		else
    164 			goto state4;
    165 	}
    166 	handler = &jmploc;
    167 #ifdef DEBUG
    168 	opentrace();
    169 	trputs("Shell args:  ");  trargs(argv);
    170 #endif
    171 	rootpid = getpid();
    172 	rootshell = 1;
    173 	init();
    174 	setstackmark(&smark);
    175 	procargs(argc, argv);
    176 	if (argv[0] && argv[0][0] == '-') {
    177 		state = 1;
    178 		read_profile("/etc/profile");
    179 state1:
    180 		state = 2;
    181 		read_profile(".profile");
    182 	}
    183 state2:
    184 	state = 3;
    185 	if (getuid() == geteuid() && getgid() == getegid()) {
    186 		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
    187 			state = 3;
    188 			read_profile(shinit);
    189 		}
    190 	}
    191 state3:
    192 	state = 4;
    193 	if (sflag == 0 || minusc) {
    194 		static int sigs[] =  {
    195 		    SIGINT, SIGQUIT, SIGHUP,
    196 #ifdef SIGTSTP
    197 		    SIGTSTP,
    198 #endif
    199 		    SIGPIPE
    200 		};
    201 #define SIGSSIZE (sizeof(sigs)/sizeof(sigs[0]))
    202 		int i;
    203 
    204 		for (i = 0; i < SIGSSIZE; i++)
    205 		    setsignal(sigs[i], 0);
    206 	}
    207 
    208 	if (minusc)
    209 		evalstring(minusc, 0);
    210 
    211 	if (sflag || minusc == NULL) {
    212 state4:	/* XXX ??? - why isn't this before the "if" statement */
    213 		cmdloop(1);
    214 	}
    215 #if PROFILE
    216 	monitor(0);
    217 #endif
    218 	exitshell(exitstatus);
    219 	/* NOTREACHED */
    220 }
    221 
    222 
    223 /*
    224  * Read and execute commands.  "Top" is nonzero for the top level command
    225  * loop; it turns on prompting if the shell is interactive.
    226  */
    227 
    228 void
    229 cmdloop(int top)
    230 {
    231 	union node *n;
    232 	struct stackmark smark;
    233 	int inter;
    234 	int numeof = 0;
    235 
    236 	TRACE(("cmdloop(%d) called\n", top));
    237 	setstackmark(&smark);
    238 	for (;;) {
    239 		if (pendingsigs)
    240 			dotrap();
    241 		inter = 0;
    242 		if (iflag && top) {
    243 			inter = 1;
    244 			showjobs(out2, SHOW_CHANGED);
    245 			chkmail(0);
    246 			flushout(&errout);
    247 		}
    248 		n = parsecmd(inter);
    249 		/* showtree(n); DEBUG */
    250 		if (n == NEOF) {
    251 			if (!top || numeof >= 50)
    252 				break;
    253 			if (!stoppedjobs()) {
    254 				if (!Iflag)
    255 					break;
    256 				out2str("\nUse \"exit\" to leave shell.\n");
    257 			}
    258 			numeof++;
    259 		} else if (n != NULL && nflag == 0) {
    260 			job_warning = (job_warning == 2) ? 1 : 0;
    261 			numeof = 0;
    262 			evaltree(n, 0);
    263 		}
    264 		popstackmark(&smark);
    265 		setstackmark(&smark);
    266 		if (evalskip == SKIPFILE) {
    267 			evalskip = 0;
    268 			break;
    269 		}
    270 	}
    271 	popstackmark(&smark);
    272 }
    273 
    274 
    275 
    276 /*
    277  * Read /etc/profile or .profile.  Return on error.
    278  */
    279 
    280 STATIC void
    281 read_profile(const char *name)
    282 {
    283 	int fd;
    284 	int xflag_set = 0;
    285 	int vflag_set = 0;
    286 
    287 	INTOFF;
    288 	if ((fd = open(name, O_RDONLY)) >= 0)
    289 		setinputfd(fd, 1);
    290 	INTON;
    291 	if (fd < 0)
    292 		return;
    293 	/* -q turns off -x and -v just when executing init files */
    294 	if (qflag)  {
    295 	    if (xflag)
    296 		    xflag = 0, xflag_set = 1;
    297 	    if (vflag)
    298 		    vflag = 0, vflag_set = 1;
    299 	}
    300 	cmdloop(0);
    301 	if (qflag)  {
    302 	    if (xflag_set)
    303 		    xflag = 1;
    304 	    if (vflag_set)
    305 		    vflag = 1;
    306 	}
    307 	popfile();
    308 }
    309 
    310 
    311 
    312 /*
    313  * Read a file containing shell functions.
    314  */
    315 
    316 void
    317 readcmdfile(char *name)
    318 {
    319 	int fd;
    320 
    321 	INTOFF;
    322 	if ((fd = open(name, O_RDONLY)) >= 0)
    323 		setinputfd(fd, 1);
    324 	else
    325 		error("Can't open %s", name);
    326 	INTON;
    327 	cmdloop(0);
    328 	popfile();
    329 }
    330 
    331 
    332 
    333 /*
    334  * Take commands from a file.  To be compatible we should do a path
    335  * search for the file, which is necessary to find sub-commands.
    336  */
    337 
    338 
    339 STATIC char *
    340 find_dot_file(char *basename)
    341 {
    342 	char *fullname;
    343 	const char *path = pathval();
    344 	struct stat statb;
    345 
    346 	/* don't try this for absolute or relative paths */
    347 	if (strchr(basename, '/'))
    348 		return basename;
    349 
    350 	while ((fullname = padvance(&path, basename)) != NULL) {
    351 		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
    352 			/*
    353 			 * Don't bother freeing here, since it will
    354 			 * be freed by the caller.
    355 			 */
    356 			return fullname;
    357 		}
    358 		stunalloc(fullname);
    359 	}
    360 
    361 	/* not found in the PATH */
    362 	error("%s: not found", basename);
    363 	/* NOTREACHED */
    364 }
    365 
    366 int
    367 dotcmd(int argc, char **argv)
    368 {
    369 	exitstatus = 0;
    370 
    371 	if (argc >= 2) {		/* That's what SVR2 does */
    372 		char *fullname;
    373 		struct stackmark smark;
    374 
    375 		setstackmark(&smark);
    376 		fullname = find_dot_file(argv[1]);
    377 		setinputfile(fullname, 1);
    378 		commandname = fullname;
    379 		cmdloop(0);
    380 		popfile();
    381 		popstackmark(&smark);
    382 	}
    383 	return exitstatus;
    384 }
    385 
    386 
    387 int
    388 exitcmd(int argc, char **argv)
    389 {
    390 	if (stoppedjobs())
    391 		return 0;
    392 	if (argc > 1)
    393 		exitstatus = number(argv[1]);
    394 	exitshell(exitstatus);
    395 	/* NOTREACHED */
    396 }
    397