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main.c revision 1.14 
      1 /*-
      2  * Copyright (c) 1991, 1993
      3  *	The Regents of the University of California.  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 static char copyright[] =
     39 "@(#) Copyright (c) 1991, 1993\n\
     40 	The Regents of the University of California.  All rights reserved.\n";
     41 #endif /* not lint */
     42 
     43 #ifndef lint
     44 /*static char sccsid[] = "from: @(#)main.c	8.1 (Berkeley) 5/31/93";*/
     45 static char *rcsid = "$Id: main.c,v 1.14 1994/08/03 16:25:26 jtc Exp $";
     46 #endif /* not lint */
     47 
     48 #include <stdio.h>
     49 #include <signal.h>
     50 #include <sys/stat.h>
     51 #include <unistd.h>
     52 #include <fcntl.h>
     53 #include "shell.h"
     54 #include "main.h"
     55 #include "mail.h"
     56 #include "options.h"
     57 #include "output.h"
     58 #include "parser.h"
     59 #include "nodes.h"
     60 #include "eval.h"
     61 #include "jobs.h"
     62 #include "input.h"
     63 #include "trap.h"
     64 #include "var.h"
     65 #include "memalloc.h"
     66 #include "error.h"
     67 #include "init.h"
     68 #include "mystring.h"
     69 #include "exec.h"
     70 
     71 #define PROFILE 0
     72 
     73 int rootpid;
     74 int rootshell;
     75 STATIC union node *curcmd;
     76 STATIC union node *prevcmd;
     77 extern int errno;
     78 #if PROFILE
     79 short profile_buf[16384];
     80 extern int etext();
     81 #endif
     82 
     83 #ifdef __STDC__
     84 STATIC void read_profile(char *);
     85 char *getenv(char *);
     86 #else
     87 STATIC void read_profile();
     88 char *getenv();
     89 #endif
     90 
     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 main(argc, argv)  char **argv; {
    101 	struct jmploc jmploc;
    102 	struct stackmark smark;
    103 	volatile int state;
    104 	char *shinit;
    105 
    106 #if PROFILE
    107 	monitor(4, etext, profile_buf, sizeof profile_buf, 50);
    108 #endif
    109 	state = 0;
    110 	if (setjmp(jmploc.loc)) {
    111 		/*
    112 		 * When a shell procedure is executed, we raise the
    113 		 * exception EXSHELLPROC to clean up before executing
    114 		 * the shell procedure.
    115 		 */
    116 		if (exception == EXSHELLPROC) {
    117 			rootpid = getpid();
    118 			rootshell = 1;
    119 			minusc = NULL;
    120 			state = 3;
    121 		} else if (state == 0 || iflag == 0 || ! rootshell)
    122 			exitshell(2);
    123 		reset();
    124 		if (exception == EXINT
    125 #if ATTY
    126 		 && (! attyset() || equal(termval(), "emacs"))
    127 #endif
    128 		 ) {
    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 if (state == 3)
    139 			goto state3;
    140 		else
    141 			goto state4;
    142 	}
    143 	handler = &jmploc;
    144 #ifdef DEBUG
    145 	opentrace();
    146 	trputs("Shell args:  ");  trargs(argv);
    147 #endif
    148 	rootpid = getpid();
    149 	rootshell = 1;
    150 	init();
    151 	setstackmark(&smark);
    152 	procargs(argc, argv);
    153 	if (argv[0] && argv[0][0] == '-') {
    154 		state = 1;
    155 		read_profile("/etc/profile");
    156 state1:
    157 		state = 2;
    158 		read_profile(".profile");
    159 	}
    160 state2:
    161 	state = 3;
    162 	if (getuid() == geteuid() && getgid() == getegid()) {
    163 		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
    164 			state = 3;
    165 			read_profile(shinit);
    166 		}
    167 	}
    168 state3:
    169 	state = 4;
    170 	if (minusc) {
    171 		evalstring(minusc);
    172 	}
    173 	if (sflag || minusc == NULL) {
    174 state4:	/* XXX ??? - why isn't this before the "if" statement */
    175 		cmdloop(1);
    176 	}
    177 #if PROFILE
    178 	monitor(0);
    179 #endif
    180 	exitshell(exitstatus);
    181 }
    182 
    183 
    184 /*
    185  * Read and execute commands.  "Top" is nonzero for the top level command
    186  * loop; it turns on prompting if the shell is interactive.
    187  */
    188 
    189 void
    190 cmdloop(top) {
    191 	union node *n;
    192 	struct stackmark smark;
    193 	int inter;
    194 	int numeof = 0;
    195 
    196 	TRACE(("cmdloop(%d) called\n", top));
    197 	setstackmark(&smark);
    198 	for (;;) {
    199 		if (pendingsigs)
    200 			dotrap();
    201 		inter = 0;
    202 		if (iflag && top) {
    203 			inter++;
    204 			showjobs(1);
    205 			chkmail(0);
    206 			flushout(&output);
    207 		}
    208 		n = parsecmd(inter);
    209 		/* showtree(n); DEBUG */
    210 		if (n == NEOF) {
    211 			if (!top || numeof >= 50)
    212 				break;
    213 			if (!stoppedjobs()) {
    214 				if (!Iflag)
    215 					break;
    216 				out2str("\nUse \"exit\" to leave shell.\n");
    217 			}
    218 			numeof++;
    219 		} else if (n != NULL && nflag == 0) {
    220 			job_warning = (job_warning == 2) ? 1 : 0;
    221 			numeof = 0;
    222 			evaltree(n, 0);
    223 		}
    224 		popstackmark(&smark);
    225 	}
    226 	popstackmark(&smark);		/* unnecessary */
    227 }
    228 
    229 
    230 
    231 /*
    232  * Read /etc/profile or .profile.  Return on error.
    233  */
    234 
    235 STATIC void
    236 read_profile(name)
    237 	char *name;
    238 	{
    239 	int fd;
    240 
    241 	INTOFF;
    242 	if ((fd = open(name, O_RDONLY)) >= 0)
    243 		setinputfd(fd, 1);
    244 	INTON;
    245 	if (fd < 0)
    246 		return;
    247 	cmdloop(0);
    248 	popfile();
    249 }
    250 
    251 
    252 
    253 /*
    254  * Read a file containing shell functions.
    255  */
    256 
    257 void
    258 readcmdfile(name)
    259 	char *name;
    260 	{
    261 	int fd;
    262 
    263 	INTOFF;
    264 	if ((fd = open(name, O_RDONLY)) >= 0)
    265 		setinputfd(fd, 1);
    266 	else
    267 		error("Can't open %s", name);
    268 	INTON;
    269 	cmdloop(0);
    270 	popfile();
    271 }
    272 
    273 
    274 
    275 /*
    276  * Take commands from a file.  To be compatable we should do a path
    277  * search for the file, which is necessary to find sub-commands.
    278  */
    279 
    280 
    281 static char *
    282 find_dot_file(basename) char *basename; {
    283 	static char localname[FILENAME_MAX+1];
    284 	char *fullname;
    285 	char *path = pathval();
    286 	struct stat statb;
    287 
    288 	/* don't try this for absolute or relative paths */
    289 	if( strchr(basename, '/'))
    290 		return basename;
    291 
    292 	while ((fullname = padvance(&path, basename)) != NULL) {
    293 		strcpy(localname, fullname);
    294 		stunalloc(fullname);
    295 		if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode))
    296 			return localname;
    297 	}
    298 	return basename;
    299 }
    300 
    301 dotcmd(argc, argv)  char **argv; {
    302 	exitstatus = 0;
    303 	if (argc >= 2) {		/* That's what SVR2 does */
    304 		char *fullname = find_dot_file(argv[1]);
    305 		setinputfile(fullname, 1);
    306 		commandname = fullname;
    307 		cmdloop(0);
    308 		popfile();
    309 	}
    310 	return exitstatus;
    311 }
    312 
    313 
    314 exitcmd(argc, argv)  char **argv; {
    315 	if (stoppedjobs())
    316 		return;
    317 	if (argc > 1)
    318 		exitstatus = number(argv[1]);
    319 	exitshell(exitstatus);
    320 }
    321 
    322 
    323 #ifdef notdef
    324 /*
    325  * Should never be called.
    326  */
    327 
    328 void
    329 exit(exitstatus) {
    330 	_exit(exitstatus);
    331 }
    332 #endif
    333