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main.c revision 1.31 
      1 /*	$NetBSD: main.c,v 1.31 1999/02/04 11:20:40 christos 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. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the University of
     21  *	California, Berkeley and its contributors.
     22  * 4. Neither the name of the University nor the names of its contributors
     23  *    may be used to endorse or promote products derived from this software
     24  *    without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     36  * SUCH DAMAGE.
     37  */
     38 
     39 #include <sys/cdefs.h>
     40 #ifndef lint
     41 __COPYRIGHT("@(#) Copyright (c) 1991, 1993\n\
     42 	The Regents of the University of California.  All rights reserved.\n");
     43 #endif /* not lint */
     44 
     45 #ifndef lint
     46 #if 0
     47 static char sccsid[] = "@(#)main.c	8.7 (Berkeley) 7/19/95";
     48 #else
     49 __RCSID("$NetBSD: main.c,v 1.31 1999/02/04 11:20:40 christos Exp $");
     50 #endif
     51 #endif /* not lint */
     52 
     53 #include <stdio.h>
     54 #include <signal.h>
     55 #include <sys/stat.h>
     56 #include <unistd.h>
     57 #include <fcntl.h>
     58 
     59 
     60 #include "shell.h"
     61 #include "main.h"
     62 #include "mail.h"
     63 #include "options.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 STATIC union node *curcmd;
     86 STATIC union node *prevcmd;
     87 extern int errno;
     88 #if PROFILE
     89 short profile_buf[16384];
     90 extern int etext();
     91 #endif
     92 
     93 STATIC void read_profile __P((char *));
     94 STATIC char *find_dot_file __P((char *));
     95 int main __P((int, char **));
     96 
     97 /*
     98  * Main routine.  We initialize things, parse the arguments, execute
     99  * profiles if we're a login shell, and then call cmdloop to execute
    100  * commands.  The setjmp call sets up the location to jump to when an
    101  * exception occurs.  When an exception occurs the variable "state"
    102  * is used to figure out how far we had gotten.
    103  */
    104 
    105 int
    106 main(argc, argv)
    107 	int argc;
    108 	char **argv;
    109 {
    110 	struct jmploc jmploc;
    111 	struct stackmark smark;
    112 	volatile int state;
    113 	char *shinit;
    114 
    115 #if PROFILE
    116 	monitor(4, etext, profile_buf, sizeof profile_buf, 50);
    117 #endif
    118 	state = 0;
    119 	if (setjmp(jmploc.loc)) {
    120 		/*
    121 		 * When a shell procedure is executed, we raise the
    122 		 * exception EXSHELLPROC to clean up before executing
    123 		 * the shell procedure.
    124 		 */
    125 		switch (exception) {
    126 		case EXSHELLPROC:
    127 			rootpid = getpid();
    128 			rootshell = 1;
    129 			minusc = NULL;
    130 			state = 3;
    131 			break;
    132 
    133 		case EXEXEC:
    134 			exitstatus = exerrno;
    135 			break;
    136 
    137 		case EXERROR:
    138 			exitstatus = 2;
    139 			break;
    140 
    141 		default:
    142 			break;
    143 		}
    144 
    145 		if (exception != EXSHELLPROC) {
    146 		    if (state == 0 || iflag == 0 || ! rootshell)
    147 			    exitshell(exitstatus);
    148 		}
    149 		reset();
    150 		if (exception == EXINT
    151 #if ATTY
    152 		 && (! attyset() || equal(termval(), "emacs"))
    153 #endif
    154 		 ) {
    155 			out2c('\n');
    156 			flushout(&errout);
    157 		}
    158 		popstackmark(&smark);
    159 		FORCEINTON;				/* enable interrupts */
    160 		if (state == 1)
    161 			goto state1;
    162 		else if (state == 2)
    163 			goto state2;
    164 		else if (state == 3)
    165 			goto state3;
    166 		else
    167 			goto state4;
    168 	}
    169 	handler = &jmploc;
    170 #ifdef DEBUG
    171 	opentrace();
    172 	trputs("Shell args:  ");  trargs(argv);
    173 #endif
    174 	rootpid = getpid();
    175 	rootshell = 1;
    176 	init();
    177 	setstackmark(&smark);
    178 	procargs(argc, argv);
    179 	if (argv[0] && argv[0][0] == '-') {
    180 		state = 1;
    181 		read_profile("/etc/profile");
    182 state1:
    183 		state = 2;
    184 		read_profile(".profile");
    185 	}
    186 state2:
    187 	state = 3;
    188 	if (getuid() == geteuid() && getgid() == getegid()) {
    189 		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
    190 			state = 3;
    191 			read_profile(shinit);
    192 		}
    193 	}
    194 state3:
    195 	state = 4;
    196 	if (minusc) {
    197 		static struct {
    198 			int   sig;
    199 			sig_t osig;
    200 			sig_t nsig;
    201 		} s[] = {
    202 			{ SIGINT, SIG_ERR, SIG_IGN },
    203 			{ SIGQUIT, SIG_ERR, SIG_IGN },
    204 			{ SIGHUP, SIG_ERR, SIG_IGN },
    205 #ifdef SIGTSTP
    206 			{ SIGTSTP, SIG_ERR, SIG_DFL },
    207 #endif
    208 			{ SIGPIPE, SIG_ERR, SIG_DFL }
    209 		};
    210 #define SIGSSIZE (sizeof(s)/sizeof(s[0]))
    211 		int i;
    212 
    213 		for (i = 0; i < SIGSSIZE; i++)
    214 		    s[i].osig = signal(s[i].sig, s[i].nsig);
    215 		evalstring(minusc);
    216 		for (i = 0; i < SIGSSIZE; i++)
    217 		    (void)signal(s[i].sig, s[i].osig);
    218 	}
    219 	if (sflag || minusc == NULL) {
    220 state4:	/* XXX ??? - why isn't this before the "if" statement */
    221 		cmdloop(1);
    222 	}
    223 #if PROFILE
    224 	monitor(0);
    225 #endif
    226 	exitshell(exitstatus);
    227 	/* NOTREACHED */
    228 }
    229 
    230 
    231 /*
    232  * Read and execute commands.  "Top" is nonzero for the top level command
    233  * loop; it turns on prompting if the shell is interactive.
    234  */
    235 
    236 void
    237 cmdloop(top)
    238 	int top;
    239 {
    240 	union node *n;
    241 	struct stackmark smark;
    242 	int inter;
    243 	int numeof = 0;
    244 
    245 	TRACE(("cmdloop(%d) called\n", top));
    246 	setstackmark(&smark);
    247 	for (;;) {
    248 		if (pendingsigs)
    249 			dotrap();
    250 		inter = 0;
    251 		if (iflag && top) {
    252 			inter++;
    253 			showjobs(1);
    254 			chkmail(0);
    255 			flushout(&output);
    256 		}
    257 		n = parsecmd(inter);
    258 		/* showtree(n); DEBUG */
    259 		if (n == NEOF) {
    260 			if (!top || numeof >= 50)
    261 				break;
    262 			if (!stoppedjobs()) {
    263 				if (!Iflag)
    264 					break;
    265 				out2str("\nUse \"exit\" to leave shell.\n");
    266 			}
    267 			numeof++;
    268 		} else if (n != NULL && nflag == 0) {
    269 			job_warning = (job_warning == 2) ? 1 : 0;
    270 			numeof = 0;
    271 			evaltree(n, 0);
    272 		}
    273 		popstackmark(&smark);
    274 		if (evalskip == SKIPFILE) {
    275 			evalskip = 0;
    276 			break;
    277 		}
    278 	}
    279 	popstackmark(&smark);		/* unnecessary */
    280 }
    281 
    282 
    283 
    284 /*
    285  * Read /etc/profile or .profile.  Return on error.
    286  */
    287 
    288 STATIC void
    289 read_profile(name)
    290 	char *name;
    291 {
    292 	int fd;
    293 	int xflag_set = 0;
    294 	int vflag_set = 0;
    295 
    296 	INTOFF;
    297 	if ((fd = open(name, O_RDONLY)) >= 0)
    298 		setinputfd(fd, 1);
    299 	INTON;
    300 	if (fd < 0)
    301 		return;
    302 	/* -q turns off -x and -v just when executing init files */
    303 	if (qflag)  {
    304 	    if (xflag)
    305 		    xflag = 0, xflag_set = 1;
    306 	    if (vflag)
    307 		    vflag = 0, vflag_set = 1;
    308 	}
    309 	cmdloop(0);
    310 	if (qflag)  {
    311 	    if (xflag_set)
    312 		    xflag = 1;
    313 	    if (vflag_set)
    314 		    vflag = 1;
    315 	}
    316 	popfile();
    317 }
    318 
    319 
    320 
    321 /*
    322  * Read a file containing shell functions.
    323  */
    324 
    325 void
    326 readcmdfile(name)
    327 	char *name;
    328 {
    329 	int fd;
    330 
    331 	INTOFF;
    332 	if ((fd = open(name, O_RDONLY)) >= 0)
    333 		setinputfd(fd, 1);
    334 	else
    335 		error("Can't open %s", name);
    336 	INTON;
    337 	cmdloop(0);
    338 	popfile();
    339 }
    340 
    341 
    342 
    343 /*
    344  * Take commands from a file.  To be compatable we should do a path
    345  * search for the file, which is necessary to find sub-commands.
    346  */
    347 
    348 
    349 STATIC char *
    350 find_dot_file(basename)
    351 	char *basename;
    352 {
    353 	char *fullname;
    354 	char *path = pathval();
    355 	struct stat statb;
    356 
    357 	/* don't try this for absolute or relative paths */
    358 	if (strchr(basename, '/'))
    359 		return basename;
    360 
    361 	while ((fullname = padvance(&path, basename)) != NULL) {
    362 		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
    363 			/*
    364 			 * Don't bother freeing here, since it will
    365 			 * be freed by the caller.
    366 			 */
    367 			return fullname;
    368 		}
    369 		stunalloc(fullname);
    370 	}
    371 
    372 	/* not found in the PATH */
    373 	error("%s: not found", basename);
    374 	/* NOTREACHED */
    375 }
    376 
    377 int
    378 dotcmd(argc, argv)
    379 	int argc;
    380 	char **argv;
    381 {
    382 	struct strlist *sp;
    383 	exitstatus = 0;
    384 
    385 	for (sp = cmdenviron; sp ; sp = sp->next)
    386 		setvareq(savestr(sp->text), VSTRFIXED|VTEXTFIXED);
    387 
    388 	if (argc >= 2) {		/* That's what SVR2 does */
    389 		char *fullname;
    390 		struct stackmark smark;
    391 
    392 		setstackmark(&smark);
    393 		fullname = find_dot_file(argv[1]);
    394 		setinputfile(fullname, 1);
    395 		commandname = fullname;
    396 		cmdloop(0);
    397 		popfile();
    398 		popstackmark(&smark);
    399 	}
    400 	return exitstatus;
    401 }
    402 
    403 
    404 int
    405 exitcmd(argc, argv)
    406 	int argc;
    407 	char **argv;
    408 {
    409 	extern int oexitstatus;
    410 
    411 	if (stoppedjobs())
    412 		return 0;
    413 	if (argc > 1)
    414 		exitstatus = number(argv[1]);
    415 	else
    416 		exitstatus = oexitstatus;
    417 	exitshell(exitstatus);
    418 	/* NOTREACHED */
    419 }
    420