bin/sh/main.c

   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  * @(#) Copyright (c) 1991, 1993 The Regents of the University of California.  All rights reserved.
  37  * @(#)main.c   8.6 (Berkeley) 5/28/95
  38  * $FreeBSD: src/bin/sh/main.c,v 1.29 2006/10/07 16:51:16 stefanf Exp $
  39  * $DragonFly: src/bin/sh/main.c,v 1.8 2007/01/13 23:36:14 pavalos Exp $
  40  */
  41
  42 #include <stdio.h>
  43 #include <signal.h>
  44 #include <sys/stat.h>
  45 #include <unistd.h>
  46 #include <fcntl.h>
  47 #include <locale.h>
  48 #include <errno.h>
  49
  50 #include "shell.h"
  51 #include "main.h"
  52 #include "mail.h"
  53 #include "options.h"
  54 #include "output.h"
  55 #include "parser.h"
  56 #include "nodes.h"
  57 #include "expand.h"
  58 #include "eval.h"
  59 #include "jobs.h"
  60 #include "input.h"
  61 #include "trap.h"
  62 #include "var.h"
  63 #include "show.h"
  64 #include "memalloc.h"
  65 #include "error.h"
  66 #include "init.h"
  67 #include "mystring.h"
  68 #include "exec.h"
  69 #include "cd.h"
  70
  71 int rootpid;
  72 int rootshell;
  73
  74 STATIC void read_profile(const char *);
  75 STATIC const char *find_dot_file(const char *);
  76
  77 extern int oexitstatus;
  78
  79 /*
  80  * Main routine.  We initialize things, parse the arguments, execute
  81  * profiles if we're a login shell, and then call cmdloop to execute
  82  * commands.  The setjmp call sets up the location to jump to when an
  83  * exception occurs.  When an exception occurs the variable "state"
  84  * is used to figure out how far we had gotten.
  85  */
  86
  87 int
  88 main(int argc, char *argv[])
  89 {
  90         struct jmploc jmploc;
  91         struct stackmark smark;
  92         volatile int state;
  93         char *shinit;
  94
  95         setlocale(LC_ALL, "");
  96         state = 0;
  97         if (setjmp(jmploc.loc)) {
  98                 /*
  99                  * When a shell procedure is executed, we raise the
 100                  * exception EXSHELLPROC to clean up before executing
 101                  * the shell procedure.
 102                  */
 103                 switch (exception) {
 104                 case EXSHELLPROC:
 105                         rootpid = getpid();
 106                         rootshell = 1;
 107                         minusc = NULL;
 108                         state = 3;
 109                         break;
 110
 111                 case EXEXEC:
 112                         exitstatus = exerrno;
 113                         break;
 114
 115                 case EXERROR:
 116                         exitstatus = 2;
 117                         break;
 118
 119                 default:
 120                         break;
 121                 }
 122
 123                 if (exception != EXSHELLPROC) {
 124                     if (state == 0 || iflag == 0 || ! rootshell)
 125                             exitshell(exitstatus);
 126                 }
 127                 reset();
 128                 if (exception == EXINT) {
 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 (getpwd() == NULL && iflag)
 154                 out2str("sh: cannot determine working directory\n");
 155         if (getpwd() != NULL)
 156                 setvar ("PWD", getpwd(), VEXPORT);
 157         if (argv[0] && argv[0][0] == '-') {
 158                 state = 1;
 159                 read_profile("/etc/profile");
 160 state1:
 161                 state = 2;
 162                 if (privileged == 0)
 163                         read_profile(".profile");
 164                 else
 165                         read_profile("/etc/suid_profile");
 166         }
 167 state2:
 168         state = 3;
 169         if (!privileged && iflag) {
 170                 if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
 171                         state = 3;
 172                         read_profile(shinit);
 173                 }
 174         }
 175 state3:
 176         state = 4;
 177         if (minusc) {
 178                 evalstring(minusc);
 179         }
 180         if (sflag || minusc == NULL) {
 181 state4: /* XXX ??? - why isn't this before the "if" statement */
 182                 cmdloop(1);
 183         }
 184         exitshell(exitstatus);
 185         /*NOTREACHED*/
 186         return 0;
 187 }
 188
 189
 190 /*
 191  * Read and execute commands.  "Top" is nonzero for the top level command
 192  * loop; it turns on prompting if the shell is interactive.
 193  */
 194
 195 void
 196 cmdloop(int top)
 197 {
 198         union node *n;
 199         struct stackmark smark;
 200         int inter;
 201         int numeof = 0;
 202
 203         TRACE(("cmdloop(%d) called\n", top));
 204         setstackmark(&smark);
 205         for (;;) {
 206                 if (pendingsigs)
 207                         dotrap();
 208                 inter = 0;
 209                 if (iflag && top) {
 210                         inter++;
 211                         showjobs(1, SHOWJOBS_DEFAULT);
 212                         chkmail(0);
 213                         flushout(&output);
 214                 }
 215                 n = parsecmd(inter);
 216                 /* showtree(n); DEBUG */
 217                 if (n == NEOF) {
 218                         if (!top || numeof >= 50)
 219                                 break;
 220                         if (!stoppedjobs()) {
 221                                 if (!Iflag)
 222                                         break;
 223                                 out2str("\nUse \"exit\" to leave shell.\n");
 224                         }
 225                         numeof++;
 226                 } else if (n != NULL && nflag == 0) {
 227                         job_warning = (job_warning == 2) ? 1 : 0;
 228                         numeof = 0;
 229                         evaltree(n, 0);
 230                 }
 231                 popstackmark(&smark);
 232                 setstackmark(&smark);
 233                 if (evalskip == SKIPFILE) {
 234                         evalskip = 0;
 235                         break;
 236                 }
 237         }
 238         popstackmark(&smark);
 239 }
 240
 241
 242
 243 /*
 244  * Read /etc/profile or .profile.  Return on error.
 245  */
 246
 247 STATIC void
 248 read_profile(const char *name)
 249 {
 250         int fd;
 251
 252         INTOFF;
 253         if ((fd = open(name, O_RDONLY)) >= 0)
 254                 setinputfd(fd, 1);
 255         INTON;
 256         if (fd < 0)
 257                 return;
 258         cmdloop(0);
 259         popfile();
 260 }
 261
 262
 263
 264 /*
 265  * Read a file containing shell functions.
 266  */
 267
 268 void
 269 readcmdfile(char *name)
 270 {
 271         int fd;
 272
 273         INTOFF;
 274         if ((fd = open(name, O_RDONLY)) >= 0)
 275                 setinputfd(fd, 1);
 276         else
 277                 error("Can't open %s: %s", name, strerror(errno));
 278         INTON;
 279         cmdloop(0);
 280         popfile();
 281 }
 282
 283
 284
 285 /*
 286  * Take commands from a file.  To be compatible we should do a path
 287  * search for the file, which is necessary to find sub-commands.
 288  */
 289
 290
 291 STATIC const char *
 292 find_dot_file(const char *basename)
 293 {
 294         static char localname[FILENAME_MAX+1];
 295         char *fullname;
 296         const char *path = pathval();
 297         struct stat statb;
 298
 299         /* don't try this for absolute or relative paths */
 300         if( strchr(basename, '/'))
 301                 return basename;
 302
 303         while ((fullname = padvance(&path, basename)) != NULL) {
 304                 strcpy(localname, fullname);
 305                 stunalloc(fullname);
 306                 if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode))
 307                         return localname;
 308         }
 309         return basename;
 310 }
 311
 312 int
 313 dotcmd(int argc, char **argv)
 314 {
 315         struct strlist *sp;
 316         const char *fullname;
 317
 318         if (argc < 2)
 319                 error("missing filename");
 320
 321         exitstatus = 0;
 322
 323         for (sp = cmdenviron; sp ; sp = sp->next)
 324                 setvareq(savestr(sp->text), VSTRFIXED|VTEXTFIXED);
 325
 326         fullname = find_dot_file(argv[1]);
 327         setinputfile(fullname, 1);
 328         commandname = fullname;
 329         cmdloop(0);
 330         popfile();
 331         return exitstatus;
 332 }
 333
 334
 335 int
 336 exitcmd(int argc, char **argv)
 337 {
 338         if (stoppedjobs())
 339                 return 0;
 340         if (argc > 1)
 341                 exitstatus = number(argv[1]);
 342         else
 343                 exitstatus = oexitstatus;
 344         exitshell(exitstatus);
 345         /*NOTREACHED*/
 346         return 0;
 347 }