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. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #ifndef lint
  34 #if 0
  35 static char sccsid[] = "@(#)main.c      8.6 (Berkeley) 5/28/95";
  36 #endif
  37 #endif /* not lint */
  38 #include <sys/cdefs.h>
  39 __FBSDID("$FreeBSD$");
  40
  41 #include <stdio.h>
  42 #include <signal.h>
  43 #include <sys/stat.h>
  44 #include <unistd.h>
  45 #include <fcntl.h>
  46 #include <locale.h>
  47 #include <errno.h>
  48
  49 #include "shell.h"
  50 #include "main.h"
  51 #include "mail.h"
  52 #include "options.h"
  53 #include "output.h"
  54 #include "parser.h"
  55 #include "nodes.h"
  56 #include "expand.h"
  57 #include "eval.h"
  58 #include "jobs.h"
  59 #include "input.h"
  60 #include "trap.h"
  61 #include "var.h"
  62 #include "show.h"
  63 #include "memalloc.h"
  64 #include "error.h"
  65 #include "mystring.h"
  66 #include "exec.h"
  67 #include "cd.h"
  68 #include "redir.h"
  69 #include "builtins.h"
  70
  71 int rootpid;
  72 int rootshell;
  73 struct jmploc main_handler;
  74 int localeisutf8, initial_localeisutf8;
  75
  76 static void reset(void);
  77 static void cmdloop(int);
  78 static void read_profile(const char *);
  79 static char *find_dot_file(char *);
  80
  81 /*
  82  * Main routine.  We initialize things, parse the arguments, execute
  83  * profiles if we're a login shell, and then call cmdloop to execute
  84  * commands.  The setjmp call sets up the location to jump to when an
  85  * exception occurs.  When an exception occurs the variable "state"
  86  * is used to figure out how far we had gotten.
  87  */
  88
  89 int
  90 main(int argc, char *argv[])
  91 {
  92         struct stackmark smark, smark2;
  93         volatile int state;
  94         char *shinit;
  95
  96         (void) setlocale(LC_ALL, "");
  97         initcharset();
  98         state = 0;
  99         if (setjmp(main_handler.loc)) {
 100                 switch (exception) {
 101                 case EXEXEC:
 102                         exitstatus = exerrno;
 103                         break;
 104
 105                 case EXERROR:
 106                         exitstatus = 2;
 107                         break;
 108
 109                 default:
 110                         break;
 111                 }
 112
 113                 if (state == 0 || iflag == 0 || ! rootshell ||
 114                     exception == EXEXIT)
 115                         exitshell(exitstatus);
 116                 reset();
 117                 if (exception == EXINT)
 118                         out2fmt_flush("\n");
 119                 popstackmark(&smark);
 120                 FORCEINTON;                             /* enable interrupts */
 121                 if (state == 1)
 122                         goto state1;
 123                 else if (state == 2)
 124                         goto state2;
 125                 else if (state == 3)
 126                         goto state3;
 127                 else
 128                         goto state4;
 129         }
 130         handler = &main_handler;
 131 #ifdef DEBUG
 132         opentrace();
 133         trputs("Shell args:  ");  trargs(argv);
 134 #endif
 135         rootpid = getpid();
 136         rootshell = 1;
 137         INTOFF;
 138         initvar();
 139         setstackmark(&smark);
 140         setstackmark(&smark2);
 141         procargs(argc, argv);
 142         pwd_init(iflag);
 143         INTON;
 144         if (iflag)
 145                 chkmail(1);
 146         if (argv[0] && argv[0][0] == '-') {
 147                 state = 1;
 148                 read_profile("/etc/profile");
 149 state1:
 150                 state = 2;
 151                 if (privileged == 0)
 152                         read_profile("${HOME-}/.profile");
 153                 else
 154                         read_profile("/etc/suid_profile");
 155         }
 156 state2:
 157         state = 3;
 158         if (!privileged && iflag) {
 159                 if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
 160                         state = 3;
 161                         read_profile(shinit);
 162                 }
 163         }
 164 state3:
 165         state = 4;
 166         popstackmark(&smark2);
 167         if (minusc) {
 168                 evalstring(minusc, sflag ? 0 : EV_EXIT);
 169         }
 170 state4:
 171         if (sflag || minusc == NULL) {
 172                 cmdloop(1);
 173         }
 174         exitshell(exitstatus);
 175         /*NOTREACHED*/
 176         return 0;
 177 }
 178
 179 static void
 180 reset(void)
 181 {
 182         reseteval();
 183         resetinput();
 184 }
 185
 186 /*
 187  * Read and execute commands.  "Top" is nonzero for the top level command
 188  * loop; it turns on prompting if the shell is interactive.
 189  */
 190
 191 static void
 192 cmdloop(int top)
 193 {
 194         union node *n;
 195         struct stackmark smark;
 196         int inter;
 197         int numeof = 0;
 198
 199         TRACE(("cmdloop(%d) called\n", top));
 200         setstackmark(&smark);
 201         for (;;) {
 202                 if (pendingsig)
 203                         dotrap();
 204                 inter = 0;
 205                 if (iflag && top) {
 206                         inter++;
 207                         showjobs(1, SHOWJOBS_DEFAULT);
 208                         chkmail(0);
 209                         flushout(&output);
 210                 }
 211                 n = parsecmd(inter);
 212                 /* showtree(n); DEBUG */
 213                 if (n == NEOF) {
 214                         if (!top || numeof >= 50)
 215                                 break;
 216                         if (!stoppedjobs()) {
 217                                 if (!Iflag)
 218                                         break;
 219                                 out2fmt_flush("\nUse \"exit\" to leave shell.\n");
 220                         }
 221                         numeof++;
 222                 } else if (n != NULL && nflag == 0) {
 223                         job_warning = (job_warning == 2) ? 1 : 0;
 224                         numeof = 0;
 225                         evaltree(n, 0);
 226                 }
 227                 popstackmark(&smark);
 228                 setstackmark(&smark);
 229                 if (evalskip != 0) {
 230                         if (evalskip == SKIPRETURN)
 231                                 evalskip = 0;
 232                         break;
 233                 }
 234         }
 235         popstackmark(&smark);
 236 }
 237
 238
 239
 240 /*
 241  * Read /etc/profile or .profile.  Return on error.
 242  */
 243
 244 static void
 245 read_profile(const char *name)
 246 {
 247         int fd;
 248         const char *expandedname;
 249
 250         expandedname = expandstr(name);
 251         if (expandedname == NULL)
 252                 return;
 253         INTOFF;
 254         if ((fd = open(expandedname, O_RDONLY | O_CLOEXEC_MAYBE)) >= 0)
 255                 setinputfd(fd, 1);
 256         INTON;
 257         if (fd < 0)
 258                 return;
 259         cmdloop(0);
 260         popfile();
 261 }
 262
 263
 264
 265 /*
 266  * Read a file containing shell functions.
 267  */
 268
 269 void
 270 readcmdfile(const char *name)
 271 {
 272         setinputfile(name, 1);
 273         cmdloop(0);
 274         popfile();
 275 }
 276
 277
 278
 279 /*
 280  * Take commands from a file.  To be compatible we should do a path
 281  * search for the file, which is necessary to find sub-commands.
 282  */
 283
 284
 285 static char *
 286 find_dot_file(char *basename)
 287 {
 288         char *fullname;
 289         const char *path = pathval();
 290         struct stat statb;
 291
 292         /* don't try this for absolute or relative paths */
 293         if( strchr(basename, '/'))
 294                 return basename;
 295
 296         while ((fullname = padvance(&path, basename)) != NULL) {
 297                 if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
 298                         /*
 299                          * Don't bother freeing here, since it will
 300                          * be freed by the caller.
 301                          */
 302                         return fullname;
 303                 }
 304                 stunalloc(fullname);
 305         }
 306         return basename;
 307 }
 308
 309 int
 310 dotcmd(int argc, char **argv)
 311 {
 312         char *filename, *fullname;
 313
 314         if (argc < 2)
 315                 error("missing filename");
 316
 317         exitstatus = 0;
 318
 319         /*
 320          * Because we have historically not supported any options,
 321          * only treat "--" specially.
 322          */
 323         filename = argc > 2 && strcmp(argv[1], "--") == 0 ? argv[2] : argv[1];
 324
 325         fullname = find_dot_file(filename);
 326         setinputfile(fullname, 1);
 327         commandname = fullname;
 328         cmdloop(0);
 329         popfile();
 330         return exitstatus;
 331 }
 332
 333
 334 int
 335 exitcmd(int argc, char **argv)
 336 {
 337         if (stoppedjobs())
 338                 return 0;
 339         if (argc > 1)
 340                 exitshell(number(argv[1]));
 341         else
 342                 exitshell_savedstatus();
 343 }