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main.c revision 1.7 
      1 /*-
      2  * Copyright (c) 1991 The Regents of the University of California.
      3  * All rights reserved.
      4  *
      5  * This code is derived from software contributed to Berkeley by
      6  * Kenneth Almquist.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. All advertising materials mentioning features or use of this software
     17  *    must display the following acknowledgement:
     18  *	This product includes software developed by the University of
     19  *	California, Berkeley and its contributors.
     20  * 4. Neither the name of the University nor the names of its contributors
     21  *    may be used to endorse or promote products derived from this software
     22  *    without specific prior written permission.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     34  * SUCH DAMAGE.
     35  */
     36 
     37 #ifndef lint
     38 char copyright[] =
     39 "@(#) Copyright (c) 1991 The Regents of the University of California.\n\
     40  All rights reserved.\n";
     41 #endif /* not lint */
     42 
     43 #ifndef lint
     44 /*static char sccsid[] = "from: @(#)main.c	5.2 (Berkeley) 3/13/91";*/
     45 static char rcsid[] = "$Id: main.c,v 1.7 1994/01/25 21:05:34 deraadt Exp $";
     46 #endif /* not lint */
     47 
     48 #include <stdio.h>
     49 #include <signal.h>
     50 #include <fcntl.h>
     51 #include <sys/stat.h>
     52 #include "shell.h"
     53 #include "main.h"
     54 #include "mail.h"
     55 #include "options.h"
     56 #include "output.h"
     57 #include "parser.h"
     58 #include "nodes.h"
     59 #include "eval.h"
     60 #include "jobs.h"
     61 #include "input.h"
     62 #include "trap.h"
     63 #include "exec.h"
     64 #include "var.h"
     65 #include "memalloc.h"
     66 #include "error.h"
     67 #include "init.h"
     68 #include "mystring.h"
     69 
     70 #define PROFILE 0
     71 
     72 int rootpid;
     73 int rootshell;
     74 STATIC union node *curcmd;
     75 STATIC union node *prevcmd;
     76 extern int errno;
     77 #if PROFILE
     78 short profile_buf[16384];
     79 extern int etext();
     80 #endif
     81 
     82 #ifdef __STDC__
     83 STATIC void read_profile(char *);
     84 char *getenv(char *);
     85 #else
     86 STATIC void read_profile();
     87 char *getenv();
     88 #endif
     89 
     90 
     91 /*
     92  * Main routine.  We initialize things, parse the arguments, execute
     93  * profiles if we're a login shell, and then call cmdloop to execute
     94  * commands.  The setjmp call sets up the location to jump to when an
     95  * exception occurs.  When an exception occurs the variable "state"
     96  * is used to figure out how far we had gotten.
     97  */
     98 
     99 main(argc, argv)  char **argv; {
    100 	struct jmploc jmploc;
    101 	struct stackmark smark;
    102 	volatile int state;
    103 	char *shinit;
    104 
    105 #if PROFILE
    106 	monitor(4, etext, profile_buf, sizeof profile_buf, 50);
    107 #endif
    108 	state = 0;
    109 	if (setjmp(jmploc.loc)) {
    110 		/*
    111 		 * When a shell procedure is executed, we raise the
    112 		 * exception EXSHELLPROC to clean up before executing
    113 		 * the shell procedure.
    114 		 */
    115 		if (exception == EXSHELLPROC) {
    116 			rootpid = getpid();
    117 			rootshell = 1;
    118 			minusc = NULL;
    119 			state = 3;
    120 		} else if (state == 0 || iflag == 0 || ! rootshell)
    121 			exitshell(2);
    122 		reset();
    123 #if ATTY
    124 		if (exception == EXINT
    125 		 && (! attyset() || equal(termval(), "emacs"))) {
    126 #else
    127 		if (exception == EXINT) {
    128 #endif
    129 			out2c('\n');
    130 			flushout(&errout);
    131 		}
    132 		popstackmark(&smark);
    133 		FORCEINTON;				/* enable interrupts */
    134 		if (state == 1)
    135 			goto state1;
    136 		else if (state == 2)
    137 			goto state2;
    138 		else
    139 			goto state3;
    140 	}
    141 	handler = &jmploc;
    142 #ifdef DEBUG
    143 	opentrace();
    144 	trputs("Shell args:  ");  trargs(argv);
    145 #endif
    146 	rootpid = getpid();
    147 	rootshell = 1;
    148 	init();
    149 	setstackmark(&smark);
    150 	procargs(argc, argv);
    151 	if (argv[0] && argv[0][0] == '-') {
    152 		state = 1;
    153 		read_profile("/etc/profile");
    154 state1:
    155 		state = 2;
    156 		read_profile(".profile");
    157 	} else if ((sflag || minusc) && (shinit = getenv("SHINIT")) != NULL) {
    158 		state = 2;
    159 		evalstring(shinit);
    160 	}
    161 state2:
    162 	state = 3;
    163 	if (minusc) {
    164 		evalstring(minusc);
    165 	}
    166 	if (sflag || minusc == NULL) {
    167 state3:
    168 		cmdloop(1);
    169 	}
    170 #if PROFILE
    171 	monitor(0);
    172 #endif
    173 	exitshell(exitstatus);
    174 }
    175 
    176 
    177 /*
    178  * Read and execute commands.  "Top" is nonzero for the top level command
    179  * loop; it turns on prompting if the shell is interactive.
    180  */
    181 
    182 void
    183 cmdloop(top) {
    184 	union node *n;
    185 	struct stackmark smark;
    186 	int inter;
    187 	int numeof;
    188 
    189 	TRACE(("cmdloop(%d) called\n", top));
    190 	setstackmark(&smark);
    191 	numeof = 0;
    192 	for (;;) {
    193 		if (pendingsigs)
    194 			dotrap();
    195 		inter = 0;
    196 		if (iflag && top) {
    197 			inter++;
    198 			showjobs(1);
    199 			chkmail(0);
    200 			flushout(&output);
    201 		}
    202 		n = parsecmd(inter);
    203 #ifdef DEBUG
    204 		/* showtree(n); */
    205 #endif
    206 		if (n == NEOF) {
    207 			if (Iflag == 0 || numeof >= 50)
    208 				break;
    209 			out2str("\nUse \"exit\" to leave shell.\n");
    210 			numeof++;
    211 		} else if (n != NULL && nflag == 0) {
    212 			if (inter) {
    213 				INTOFF;
    214 				if (prevcmd)
    215 					freefunc(prevcmd);
    216 				prevcmd = curcmd;
    217 				curcmd = copyfunc(n);
    218 				INTON;
    219 			}
    220 			evaltree(n, 0);
    221 #ifdef notdef
    222 			if (exitstatus)				      /*DEBUG*/
    223 				outfmt(&errout, "Exit status 0x%X\n", exitstatus);
    224 #endif
    225 		}
    226 		popstackmark(&smark);
    227 	}
    228 	popstackmark(&smark);		/* unnecessary */
    229 }
    230 
    231 
    232 
    233 /*
    234  * Read /etc/profile or .profile.  Return on error.
    235  */
    236 
    237 STATIC void
    238 read_profile(name)
    239 	char *name;
    240 	{
    241 	int fd;
    242 
    243 	INTOFF;
    244 	if ((fd = open(name, O_RDONLY)) >= 0)
    245 		setinputfd(fd, 1);
    246 	INTON;
    247 	if (fd < 0)
    248 		return;
    249 	cmdloop(0);
    250 	popfile();
    251 }
    252 
    253 
    254 
    255 /*
    256  * Read a file containing shell functions.
    257  */
    258 
    259 void
    260 readcmdfile(name)
    261 	char *name;
    262 	{
    263 	int fd;
    264 
    265 	INTOFF;
    266 	if ((fd = open(name, O_RDONLY)) >= 0)
    267 		setinputfd(fd, 1);
    268 	else
    269 		error("Can't open %s", name);
    270 	INTON;
    271 	cmdloop(0);
    272 	popfile();
    273 }
    274 
    275 
    276 
    277 /*
    278  * Take commands from a file.  To be compatable we should do a path
    279  * search for the file, which is necessary to find sub-commands.
    280  */
    281 
    282 
    283 static char *
    284 find_dot_file(basename) char *basename; {
    285 	static char localname[FILENAME_MAX+1];
    286 	char *fullname;
    287 	char *path = pathval();
    288 	struct stat statb;
    289 
    290 	/* don't try this for absolute or relative paths */
    291 	if( strchr(basename, '/'))
    292 		return basename;
    293 
    294 	while ((fullname = padvance(&path, basename)) != NULL) {
    295 		strcpy(localname, fullname);
    296 		stunalloc(fullname);
    297 		if ((stat(fullname, &statb) == 0) &&
    298 		    (S_ISREG(statb.st_mode) || S_ISLNK(statb.st_mode)))
    299 			return localname;
    300 	}
    301 	return basename;
    302 }
    303 
    304 dotcmd(argc, argv)  char **argv; {
    305 	exitstatus = 0;
    306 	if (argc >= 2) {		/* That's what SVR2 does */
    307 		char *fullname = find_dot_file(argv[1]);
    308 		setinputfile(fullname, 1);
    309 		commandname = fullname;
    310 		cmdloop(0);
    311 		popfile();
    312 	}
    313 	return exitstatus;
    314 }
    315 
    316 
    317 exitcmd(argc, argv)  char **argv; {
    318 	if (argc > 1)
    319 		exitstatus = number(argv[1]);
    320 	exitshell(exitstatus);
    321 }
    322 
    323 
    324 lccmd(argc, argv)  char **argv; {
    325 	if (argc > 1) {
    326 		defun(argv[1], prevcmd);
    327 		return 0;
    328 	} else {
    329 		INTOFF;
    330 		freefunc(curcmd);
    331 		curcmd = prevcmd;
    332 		prevcmd = NULL;
    333 		INTON;
    334 		evaltree(curcmd, 0);
    335 		return exitstatus;
    336 	}
    337 }
    338 
    339 
    340 
    341 #ifdef notdef
    342 /*
    343  * Should never be called.
    344  */
    345 
    346 void
    347 exit(exitstatus) {
    348 	_exit(exitstatus);
    349 }
    350 #endif
    351