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      1 /*	$NetBSD: main.c,v 1.48 2003/09/14 12:09:29 jmmv 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 1.48 2003/09/14 12:09:29 jmmv 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 <fcntl.h>
     55 
     56 
     57 #include "shell.h"
     58 #include "main.h"
     59 #include "options.h"
     60 #include "output.h"
     61 #include "parser.h"
     62 #include "nodes.h"
     63 #include "expand.h"
     64 #include "eval.h"
     65 #include "jobs.h"
     66 #include "input.h"
     67 #include "trap.h"
     68 #include "var.h"
     69 #include "show.h"
     70 #include "memalloc.h"
     71 #include "error.h"
     72 #include "init.h"
     73 #include "mystring.h"
     74 #include "exec.h"
     75 #include "cd.h"
     76 
     77 #define PROFILE 0
     78 
     79 int rootpid;
     80 int rootshell;
     81 STATIC union node *curcmd;
     82 STATIC union node *prevcmd;
     83 #if PROFILE
     84 short profile_buf[16384];
     85 extern int etext();
     86 #endif
     87 
     88 STATIC void read_profile(const char *);
     89 STATIC char *find_dot_file(char *);
     90 int main(int, char **);
     91 
     92 /*
     93  * Main routine.  We initialize things, parse the arguments, execute
     94  * profiles if we're a login shell, and then call cmdloop to execute
     95  * commands.  The setjmp call sets up the location to jump to when an
     96  * exception occurs.  When an exception occurs the variable "state"
     97  * is used to figure out how far we had gotten.
     98  */
     99 
    100 int
    101 main(int argc, char **argv)
    102 {
    103 	struct jmploc jmploc;
    104 	struct stackmark smark;
    105 	volatile int state;
    106 	char *shinit;
    107 
    108 #if PROFILE
    109 	monitor(4, etext, profile_buf, sizeof profile_buf, 50);
    110 #endif
    111 	state = 0;
    112 	if (setjmp(jmploc.loc)) {
    113 		/*
    114 		 * When a shell procedure is executed, we raise the
    115 		 * exception EXSHELLPROC to clean up before executing
    116 		 * the shell procedure.
    117 		 */
    118 		switch (exception) {
    119 		case EXSHELLPROC:
    120 			rootpid = getpid();
    121 			rootshell = 1;
    122 			minusc = NULL;
    123 			state = 3;
    124 			break;
    125 
    126 		case EXEXEC:
    127 			exitstatus = exerrno;
    128 			break;
    129 
    130 		case EXERROR:
    131 			exitstatus = 2;
    132 			break;
    133 
    134 		default:
    135 			break;
    136 		}
    137 
    138 		if (exception != EXSHELLPROC) {
    139 			if (state == 0 || iflag == 0 || ! rootshell)
    140 				exitshell(exitstatus);
    141 		}
    142 		reset();
    143 		if (exception == EXINT
    144 #if ATTY
    145 		 && (! attyset() || equal(termval(), "emacs"))
    146 #endif
    147 		 ) {
    148 			out2c('\n');
    149 			flushout(&errout);
    150 		}
    151 		popstackmark(&smark);
    152 		FORCEINTON;				/* enable interrupts */
    153 		if (state == 1)
    154 			goto state1;
    155 		else if (state == 2)
    156 			goto state2;
    157 		else if (state == 3)
    158 			goto state3;
    159 		else
    160 			goto state4;
    161 	}
    162 	handler = &jmploc;
    163 #ifdef DEBUG
    164 #if DEBUG == 2
    165 	debug = 1;
    166 #endif
    167 	opentrace();
    168 	trputs("Shell args:  ");  trargs(argv);
    169 #endif
    170 	rootpid = getpid();
    171 	rootshell = 1;
    172 	init();
    173 	setstackmark(&smark);
    174 	procargs(argc, argv);
    175 	if (argv[0] && argv[0][0] == '-') {
    176 		state = 1;
    177 		read_profile("/etc/profile");
    178 state1:
    179 		state = 2;
    180 		read_profile(".profile");
    181 	}
    182 state2:
    183 	state = 3;
    184 	if (getuid() == geteuid() && getgid() == getegid()) {
    185 		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
    186 			state = 3;
    187 			read_profile(shinit);
    188 		}
    189 	}
    190 state3:
    191 	state = 4;
    192 	if (sflag == 0 || minusc) {
    193 		static int sigs[] =  {
    194 		    SIGINT, SIGQUIT, SIGHUP,
    195 #ifdef SIGTSTP
    196 		    SIGTSTP,
    197 #endif
    198 		    SIGPIPE
    199 		};
    200 #define SIGSSIZE (sizeof(sigs)/sizeof(sigs[0]))
    201 		int i;
    202 
    203 		for (i = 0; i < SIGSSIZE; i++)
    204 		    setsignal(sigs[i], 0);
    205 	}
    206 
    207 	if (minusc)
    208 		evalstring(minusc, 0);
    209 
    210 	if (sflag || minusc == NULL) {
    211 state4:	/* XXX ??? - why isn't this before the "if" statement */
    212 		cmdloop(1);
    213 	}
    214 #if PROFILE
    215 	monitor(0);
    216 #endif
    217 	exitshell(exitstatus);
    218 	/* NOTREACHED */
    219 }
    220 
    221 
    222 /*
    223  * Read and execute commands.  "Top" is nonzero for the top level command
    224  * loop; it turns on prompting if the shell is interactive.
    225  */
    226 
    227 void
    228 cmdloop(int top)
    229 {
    230 	union node *n;
    231 	struct stackmark smark;
    232 	int inter;
    233 	int numeof = 0;
    234 
    235 	TRACE(("cmdloop(%d) called\n", top));
    236 	setstackmark(&smark);
    237 	for (;;) {
    238 		if (pendingsigs)
    239 			dotrap();
    240 		inter = 0;
    241 		if (iflag && top) {
    242 			inter = 1;
    243 			showjobs(out2, SHOW_CHANGED);
    244 			flushout(&errout);
    245 		}
    246 		n = parsecmd(inter);
    247 		/* showtree(n); DEBUG */
    248 		if (n == NEOF) {
    249 			if (!top || numeof >= 50)
    250 				break;
    251 			if (!stoppedjobs()) {
    252 				if (!Iflag)
    253 					break;
    254 				out2str("\nUse \"exit\" to leave shell.\n");
    255 			}
    256 			numeof++;
    257 		} else if (n != NULL && nflag == 0) {
    258 			job_warning = (job_warning == 2) ? 1 : 0;
    259 			numeof = 0;
    260 			evaltree(n, 0);
    261 		}
    262 		popstackmark(&smark);
    263 		setstackmark(&smark);
    264 		if (evalskip == SKIPFILE) {
    265 			evalskip = 0;
    266 			break;
    267 		}
    268 	}
    269 	popstackmark(&smark);
    270 }
    271 
    272 
    273 
    274 /*
    275  * Read /etc/profile or .profile.  Return on error.
    276  */
    277 
    278 STATIC void
    279 read_profile(const char *name)
    280 {
    281 	int fd;
    282 	int xflag_set = 0;
    283 	int vflag_set = 0;
    284 
    285 	INTOFF;
    286 	if ((fd = open(name, O_RDONLY)) >= 0)
    287 		setinputfd(fd, 1);
    288 	INTON;
    289 	if (fd < 0)
    290 		return;
    291 	/* -q turns off -x and -v just when executing init files */
    292 	if (qflag)  {
    293 	    if (xflag)
    294 		    xflag = 0, xflag_set = 1;
    295 	    if (vflag)
    296 		    vflag = 0, vflag_set = 1;
    297 	}
    298 	cmdloop(0);
    299 	if (qflag)  {
    300 	    if (xflag_set)
    301 		    xflag = 1;
    302 	    if (vflag_set)
    303 		    vflag = 1;
    304 	}
    305 	popfile();
    306 }
    307 
    308 
    309 
    310 /*
    311  * Read a file containing shell functions.
    312  */
    313 
    314 void
    315 readcmdfile(char *name)
    316 {
    317 	int fd;
    318 
    319 	INTOFF;
    320 	if ((fd = open(name, O_RDONLY)) >= 0)
    321 		setinputfd(fd, 1);
    322 	else
    323 		error("Can't open %s", name);
    324 	INTON;
    325 	cmdloop(0);
    326 	popfile();
    327 }
    328 
    329 
    330 
    331 /*
    332  * Take commands from a file.  To be compatible we should do a path
    333  * search for the file, which is necessary to find sub-commands.
    334  */
    335 
    336 
    337 STATIC char *
    338 find_dot_file(char *basename)
    339 {
    340 	char *fullname;
    341 	const char *path = pathval();
    342 	struct stat statb;
    343 
    344 	/* don't try this for absolute or relative paths */
    345 	if (strchr(basename, '/'))
    346 		return basename;
    347 
    348 	while ((fullname = padvance(&path, basename)) != NULL) {
    349 		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
    350 			/*
    351 			 * Don't bother freeing here, since it will
    352 			 * be freed by the caller.
    353 			 */
    354 			return fullname;
    355 		}
    356 		stunalloc(fullname);
    357 	}
    358 
    359 	/* not found in the PATH */
    360 	error("%s: not found", basename);
    361 	/* NOTREACHED */
    362 }
    363 
    364 int
    365 dotcmd(int argc, char **argv)
    366 {
    367 	exitstatus = 0;
    368 
    369 	if (argc >= 2) {		/* That's what SVR2 does */
    370 		char *fullname;
    371 		struct stackmark smark;
    372 
    373 		setstackmark(&smark);
    374 		fullname = find_dot_file(argv[1]);
    375 		setinputfile(fullname, 1);
    376 		commandname = fullname;
    377 		cmdloop(0);
    378 		popfile();
    379 		popstackmark(&smark);
    380 	}
    381 	return exitstatus;
    382 }
    383 
    384 
    385 int
    386 exitcmd(int argc, char **argv)
    387 {
    388 	if (stoppedjobs())
    389 		return 0;
    390 	if (argc > 1)
    391 		exitstatus = number(argv[1]);
    392 	exitshell(exitstatus);
    393 	/* NOTREACHED */
    394 }
    395