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main.c revision 1.51 
      1 /*	$NetBSD: main.c,v 1.51 2008/07/20 00:52:40 lukem 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 1.51 2008/07/20 00:52:40 lukem 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 #if DEBUG == 2
    169 	debug = 1;
    170 #endif
    171 	opentrace();
    172 	trputs("Shell args:  ");  trargs(argv);
    173 #endif
    174 	rootpid = getpid();
    175 	rootshell = 1;
    176 	init();
    177 	initpwd();
    178 	setstackmark(&smark);
    179 	procargs(argc, argv);
    180 	if (argv[0] && argv[0][0] == '-') {
    181 		state = 1;
    182 		read_profile("/etc/profile");
    183 state1:
    184 		state = 2;
    185 		read_profile(".profile");
    186 	}
    187 state2:
    188 	state = 3;
    189 	if (getuid() == geteuid() && getgid() == getegid()) {
    190 		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
    191 			state = 3;
    192 			read_profile(shinit);
    193 		}
    194 	}
    195 state3:
    196 	state = 4;
    197 	if (sflag == 0 || minusc) {
    198 		static int sigs[] =  {
    199 		    SIGINT, SIGQUIT, SIGHUP,
    200 #ifdef SIGTSTP
    201 		    SIGTSTP,
    202 #endif
    203 		    SIGPIPE
    204 		};
    205 #define SIGSSIZE (sizeof(sigs)/sizeof(sigs[0]))
    206 		int i;
    207 
    208 		for (i = 0; i < SIGSSIZE; i++)
    209 		    setsignal(sigs[i], 0);
    210 	}
    211 
    212 	if (minusc)
    213 		evalstring(minusc, 0);
    214 
    215 	if (sflag || minusc == NULL) {
    216 state4:	/* XXX ??? - why isn't this before the "if" statement */
    217 		cmdloop(1);
    218 	}
    219 #if PROFILE
    220 	monitor(0);
    221 #endif
    222 	exitshell(exitstatus);
    223 	/* NOTREACHED */
    224 }
    225 
    226 
    227 /*
    228  * Read and execute commands.  "Top" is nonzero for the top level command
    229  * loop; it turns on prompting if the shell is interactive.
    230  */
    231 
    232 void
    233 cmdloop(int top)
    234 {
    235 	union node *n;
    236 	struct stackmark smark;
    237 	int inter;
    238 	int numeof = 0;
    239 
    240 	TRACE(("cmdloop(%d) called\n", top));
    241 	setstackmark(&smark);
    242 	for (;;) {
    243 		if (pendingsigs)
    244 			dotrap();
    245 		inter = 0;
    246 		if (iflag == 1 && top) {
    247 			inter = 1;
    248 			showjobs(out2, SHOW_CHANGED);
    249 			chkmail(0);
    250 			flushout(&errout);
    251 		}
    252 		n = parsecmd(inter);
    253 		/* showtree(n); DEBUG */
    254 		if (n == NEOF) {
    255 			if (!top || numeof >= 50)
    256 				break;
    257 			if (!stoppedjobs()) {
    258 				if (!Iflag)
    259 					break;
    260 				out2str("\nUse \"exit\" to leave shell.\n");
    261 			}
    262 			numeof++;
    263 		} else if (n != NULL && nflag == 0) {
    264 			job_warning = (job_warning == 2) ? 1 : 0;
    265 			numeof = 0;
    266 			evaltree(n, 0);
    267 		}
    268 		popstackmark(&smark);
    269 		setstackmark(&smark);
    270 		if (evalskip == SKIPFILE) {
    271 			evalskip = 0;
    272 			break;
    273 		}
    274 	}
    275 	popstackmark(&smark);
    276 }
    277 
    278 
    279 
    280 /*
    281  * Read /etc/profile or .profile.  Return on error.
    282  */
    283 
    284 STATIC void
    285 read_profile(const char *name)
    286 {
    287 	int fd;
    288 	int xflag_set = 0;
    289 	int vflag_set = 0;
    290 
    291 	INTOFF;
    292 	if ((fd = open(name, O_RDONLY)) >= 0)
    293 		setinputfd(fd, 1);
    294 	INTON;
    295 	if (fd < 0)
    296 		return;
    297 	/* -q turns off -x and -v just when executing init files */
    298 	if (qflag)  {
    299 	    if (xflag)
    300 		    xflag = 0, xflag_set = 1;
    301 	    if (vflag)
    302 		    vflag = 0, vflag_set = 1;
    303 	}
    304 	cmdloop(0);
    305 	if (qflag)  {
    306 	    if (xflag_set)
    307 		    xflag = 1;
    308 	    if (vflag_set)
    309 		    vflag = 1;
    310 	}
    311 	popfile();
    312 }
    313 
    314 
    315 
    316 /*
    317  * Read a file containing shell functions.
    318  */
    319 
    320 void
    321 readcmdfile(char *name)
    322 {
    323 	int fd;
    324 
    325 	INTOFF;
    326 	if ((fd = open(name, O_RDONLY)) >= 0)
    327 		setinputfd(fd, 1);
    328 	else
    329 		error("Can't open %s", name);
    330 	INTON;
    331 	cmdloop(0);
    332 	popfile();
    333 }
    334 
    335 
    336 
    337 /*
    338  * Take commands from a file.  To be compatible we should do a path
    339  * search for the file, which is necessary to find sub-commands.
    340  */
    341 
    342 
    343 STATIC char *
    344 find_dot_file(char *basename)
    345 {
    346 	char *fullname;
    347 	const char *path = pathval();
    348 	struct stat statb;
    349 
    350 	/* don't try this for absolute or relative paths */
    351 	if (strchr(basename, '/'))
    352 		return basename;
    353 
    354 	while ((fullname = padvance(&path, basename)) != NULL) {
    355 		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
    356 			/*
    357 			 * Don't bother freeing here, since it will
    358 			 * be freed by the caller.
    359 			 */
    360 			return fullname;
    361 		}
    362 		stunalloc(fullname);
    363 	}
    364 
    365 	/* not found in the PATH */
    366 	error("%s: not found", basename);
    367 	/* NOTREACHED */
    368 }
    369 
    370 int
    371 dotcmd(int argc, char **argv)
    372 {
    373 	exitstatus = 0;
    374 
    375 	if (argc >= 2) {		/* That's what SVR2 does */
    376 		char *fullname;
    377 		struct stackmark smark;
    378 
    379 		setstackmark(&smark);
    380 		fullname = find_dot_file(argv[1]);
    381 		setinputfile(fullname, 1);
    382 		commandname = fullname;
    383 		cmdloop(0);
    384 		popfile();
    385 		popstackmark(&smark);
    386 	}
    387 	return exitstatus;
    388 }
    389 
    390 
    391 int
    392 exitcmd(int argc, char **argv)
    393 {
    394 	if (stoppedjobs())
    395 		return 0;
    396 	if (argc > 1)
    397 		exitstatus = number(argv[1]);
    398 	exitshell(exitstatus);
    399 	/* NOTREACHED */
    400 }
    401