bin/sh/main.c

   1 /*      $NetBSD: main.c,v 1.52 2008/10/16 14:55:28 dholland 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\
  38  The Regents of the University of California.  All rights reserved.");
  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 1.52 2008/10/16 14:55:28 dholland 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 <locale.h>
  55 #include <fcntl.h>
  56
  57
  58 #include "shell.h"
  59 #include "main.h"
  60 #include "mail.h"
  61 #include "options.h"
  62 #include "output.h"
  63 #include "parser.h"
  64 #include "nodes.h"
  65 #include "expand.h"
  66 #include "eval.h"
  67 #include "jobs.h"
  68 #include "input.h"
  69 #include "trap.h"
  70 #include "var.h"
  71 #include "show.h"
  72 #include "memalloc.h"
  73 #include "error.h"
  74 #include "init.h"
  75 #include "mystring.h"
  76 #include "exec.h"
  77 #include "cd.h"
  78
  79 #define PROFILE 0
  80
  81 int rootpid;
  82 int rootshell;
  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         setlocale(LC_ALL, "");
 109
 110 #if PROFILE
 111         monitor(4, etext, profile_buf, sizeof profile_buf, 50);
 112 #endif
 113         state = 0;
 114         if (setjmp(jmploc.loc)) {
 115                 /*
 116                  * When a shell procedure is executed, we raise the
 117                  * exception EXSHELLPROC to clean up before executing
 118                  * the shell procedure.
 119                  */
 120                 switch (exception) {
 121                 case EXSHELLPROC:
 122                         rootpid = getpid();
 123                         rootshell = 1;
 124                         minusc = NULL;
 125                         state = 3;
 126                         break;
 127
 128                 case EXEXEC:
 129                         exitstatus = exerrno;
 130                         break;
 131
 132                 case EXERROR:
 133                         exitstatus = 2;
 134                         break;
 135
 136                 default:
 137                         break;
 138                 }
 139
 140                 if (exception != EXSHELLPROC) {
 141                         if (state == 0 || iflag == 0 || ! rootshell)
 142                                 exitshell(exitstatus);
 143                 }
 144                 reset();
 145                 if (exception == EXINT
 146 #if ATTY
 147                  && (! attyset() || equal(termval(), "emacs"))
 148 #endif
 149                  ) {
 150                         out2c('\n');
 151                         flushout(&errout);
 152                 }
 153                 popstackmark(&smark);
 154                 FORCEINTON;                             /* enable interrupts */
 155                 if (state == 1)
 156                         goto state1;
 157                 else if (state == 2)
 158                         goto state2;
 159                 else if (state == 3)
 160                         goto state3;
 161                 else
 162                         goto state4;
 163         }
 164         handler = &jmploc;
 165 #ifdef DEBUG
 166 #if DEBUG == 2
 167         debug = 1;
 168 #endif
 169         opentrace();
 170         trputs("Shell args:  ");  trargs(argv);
 171 #endif
 172         rootpid = getpid();
 173         rootshell = 1;
 174         init();
 175         initpwd();
 176         setstackmark(&smark);
 177         procargs(argc, argv);
 178         if (argv[0] && argv[0][0] == '-') {
 179                 state = 1;
 180                 read_profile("/etc/profile");
 181 state1:
 182                 state = 2;
 183                 read_profile(".profile");
 184         }
 185 state2:
 186         state = 3;
 187         if (getuid() == geteuid() && getgid() == getegid()) {
 188                 if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
 189                         state = 3;
 190                         read_profile(shinit);
 191                 }
 192         }
 193 state3:
 194         state = 4;
 195         if (sflag == 0 || minusc) {
 196                 static int sigs[] =  {
 197                     SIGINT, SIGQUIT, SIGHUP,
 198 #ifdef SIGTSTP
 199                     SIGTSTP,
 200 #endif
 201                     SIGPIPE
 202                 };
 203 #define SIGSSIZE (sizeof(sigs)/sizeof(sigs[0]))
 204                 size_t i;
 205
 206                 for (i = 0; i < SIGSSIZE; i++)
 207                     setsignal(sigs[i], 0);
 208         }
 209
 210         if (minusc)
 211                 evalstring(minusc, 0);
 212
 213         if (sflag || minusc == NULL) {
 214 state4: /* XXX ??? - why isn't this before the "if" statement */
 215                 cmdloop(1);
 216         }
 217 #if PROFILE
 218         monitor(0);
 219 #endif
 220         exitshell(exitstatus);
 221         /* NOTREACHED */
 222 }
 223
 224
 225 /*
 226  * Read and execute commands.  "Top" is nonzero for the top level command
 227  * loop; it turns on prompting if the shell is interactive.
 228  */
 229
 230 void
 231 cmdloop(int top)
 232 {
 233         union node *n;
 234         struct stackmark smark;
 235         int inter;
 236         int numeof = 0;
 237
 238         TRACE(("cmdloop(%d) called\n", top));
 239         setstackmark(&smark);
 240         for (;;) {
 241                 if (pendingsigs)
 242                         dotrap();
 243                 inter = 0;
 244                 if (iflag == 1 && top) {
 245                         inter = 1;
 246                         showjobs(out2, SHOW_CHANGED);
 247                         chkmail(0);
 248                         flushout(&errout);
 249                 }
 250                 n = parsecmd(inter);
 251                 /* showtree(n); DEBUG */
 252                 if (n == NEOF) {
 253                         if (!top || numeof >= 50)
 254                                 break;
 255                         if (!stoppedjobs()) {
 256                                 if (!Iflag)
 257                                         break;
 258                                 out2str("\nUse \"exit\" to leave shell.\n");
 259                         }
 260                         numeof++;
 261                 } else if (n != NULL && nflag == 0) {
 262                         job_warning = (job_warning == 2) ? 1 : 0;
 263                         numeof = 0;
 264                         evaltree(n, 0);
 265                 }
 266                 popstackmark(&smark);
 267                 setstackmark(&smark);
 268                 if (evalskip == SKIPFILE) {
 269                         evalskip = 0;
 270                         break;
 271                 }
 272         }
 273         popstackmark(&smark);
 274 }
 275
 276
 277
 278 /*
 279  * Read /etc/profile or .profile.  Return on error.
 280  */
 281
 282 STATIC void
 283 read_profile(const char *name)
 284 {
 285         int fd;
 286         int xflag_set = 0;
 287         int vflag_set = 0;
 288
 289         INTOFF;
 290         if ((fd = open(name, O_RDONLY)) >= 0)
 291                 setinputfd(fd, 1);
 292         INTON;
 293         if (fd < 0)
 294                 return;
 295         /* -q turns off -x and -v just when executing init files */
 296         if (qflag)  {
 297             if (xflag)
 298                     xflag = 0, xflag_set = 1;
 299             if (vflag)
 300                     vflag = 0, vflag_set = 1;
 301         }
 302         cmdloop(0);
 303         if (qflag)  {
 304             if (xflag_set)
 305                     xflag = 1;
 306             if (vflag_set)
 307                     vflag = 1;
 308         }
 309         popfile();
 310 }
 311
 312
 313
 314 /*
 315  * Read a file containing shell functions.
 316  */
 317
 318 void
 319 readcmdfile(char *name)
 320 {
 321         int fd;
 322
 323         INTOFF;
 324         if ((fd = open(name, O_RDONLY)) >= 0)
 325                 setinputfd(fd, 1);
 326         else
 327                 error("Can't open %s", name);
 328         INTON;
 329         cmdloop(0);
 330         popfile();
 331 }
 332
 333
 334
 335 /*
 336  * Take commands from a file.  To be compatible we should do a path
 337  * search for the file, which is necessary to find sub-commands.
 338  */
 339
 340
 341 STATIC char *
 342 find_dot_file(char *basename)
 343 {
 344         char *fullname;
 345         const char *path = pathval();
 346         struct stat statb;
 347
 348         /* don't try this for absolute or relative paths */
 349         if (strchr(basename, '/'))
 350                 return basename;
 351
 352         while ((fullname = padvance(&path, basename)) != NULL) {
 353                 if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
 354                         /*
 355                          * Don't bother freeing here, since it will
 356                          * be freed by the caller.
 357                          */
 358                         return fullname;
 359                 }
 360                 stunalloc(fullname);
 361         }
 362
 363         /* not found in the PATH */
 364         error("%s: not found", basename);
 365         /* NOTREACHED */
 366 }
 367
 368 int
 369 dotcmd(int argc, char **argv)
 370 {
 371         exitstatus = 0;
 372
 373         if (argc >= 2) {                /* That's what SVR2 does */
 374                 char *fullname;
 375                 struct stackmark smark;
 376
 377                 setstackmark(&smark);
 378                 fullname = find_dot_file(argv[1]);
 379                 setinputfile(fullname, 1);
 380                 commandname = fullname;
 381                 cmdloop(0);
 382                 popfile();
 383                 popstackmark(&smark);
 384         }
 385         return exitstatus;
 386 }
 387
 388
 389 int
 390 exitcmd(int argc, char **argv)
 391 {
 392         if (stoppedjobs())
 393                 return 0;
 394         if (argc > 1)
 395                 exitstatus = number(argv[1]);
 396         exitshell(exitstatus);
 397         /* NOTREACHED */
 398 }