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 static char const copyright[] =
  35 "@(#) Copyright (c) 1991, 1993\n\
  36         The Regents of the University of California.  All rights reserved.\n";
  37 #endif /* not lint */
  38
  39 #ifndef lint
  40 #if 0
  41 static char sccsid[] = "@(#)main.c      8.6 (Berkeley) 5/28/95";
  42 #endif
  43 #endif /* not lint */
  44 #include <sys/cdefs.h>
  45 __FBSDID("$FreeBSD$");
  46
  47 #include <stdio.h>
  48 #include <signal.h>
  49 #include <sys/stat.h>
  50 #include <unistd.h>
  51 #include <fcntl.h>
  52 #include <locale.h>
  53 #include <errno.h>
  54
  55 #include "shell.h"
  56 #include "main.h"
  57 #include "mail.h"
  58 #include "options.h"
  59 #include "output.h"
  60 #include "parser.h"
  61 #include "nodes.h"
  62 #include "expand.h"
  63 #include "eval.h"
  64 #include "jobs.h"
  65 #include "input.h"
  66 #include "trap.h"
  67 #include "var.h"
  68 #include "show.h"
  69 #include "memalloc.h"
  70 #include "error.h"
  71 #include "mystring.h"
  72 #include "exec.h"
  73 #include "cd.h"
  74 #include "redir.h"
  75 #include "builtins.h"
  76
  77 int rootpid;
  78 int rootshell;
  79 struct jmploc main_handler;
  80 int localeisutf8, initial_localeisutf8;
  81
  82 static void reset(void);
  83 static void cmdloop(int);
  84 static void read_profile(const char *);
  85 static char *find_dot_file(char *);
  86
  87 /*
  88  * Main routine.  We initialize things, parse the arguments, execute
  89  * profiles if we're a login shell, and then call cmdloop to execute
  90  * commands.  The setjmp call sets up the location to jump to when an
  91  * exception occurs.  When an exception occurs the variable "state"
  92  * is used to figure out how far we had gotten.
  93  */
  94
  95 int
  96 main(int argc, char *argv[])
  97 {
  98         struct stackmark smark, smark2;
  99         volatile int state;
 100         char *shinit;
 101
 102         (void) setlocale(LC_ALL, "");
 103         initcharset();
 104         state = 0;
 105         if (setjmp(main_handler.loc)) {
 106                 switch (exception) {
 107                 case EXEXEC:
 108                         exitstatus = exerrno;
 109                         break;
 110
 111                 case EXERROR:
 112                         exitstatus = 2;
 113                         break;
 114
 115                 default:
 116                         break;
 117                 }
 118
 119                 if (state == 0 || iflag == 0 || ! rootshell ||
 120                     exception == EXEXIT)
 121                         exitshell(exitstatus);
 122                 reset();
 123                 if (exception == EXINT)
 124                         out2fmt_flush("\n");
 125                 popstackmark(&smark);
 126                 FORCEINTON;                             /* enable interrupts */
 127                 if (state == 1)
 128                         goto state1;
 129                 else if (state == 2)
 130                         goto state2;
 131                 else if (state == 3)
 132                         goto state3;
 133                 else
 134                         goto state4;
 135         }
 136         handler = &main_handler;
 137 #ifdef DEBUG
 138         opentrace();
 139         trputs("Shell args:  ");  trargs(argv);
 140 #endif
 141         rootpid = getpid();
 142         rootshell = 1;
 143         INTOFF;
 144         initvar();
 145         setstackmark(&smark);
 146         setstackmark(&smark2);
 147         procargs(argc, argv);
 148         pwd_init(iflag);
 149         INTON;
 150         if (iflag)
 151                 chkmail(1);
 152         if (argv[0] && argv[0][0] == '-') {
 153                 state = 1;
 154                 read_profile("/etc/profile");
 155 state1:
 156                 state = 2;
 157                 if (privileged == 0)
 158                         read_profile("${HOME-}/.profile");
 159                 else
 160                         read_profile("/etc/suid_profile");
 161         }
 162 state2:
 163         state = 3;
 164         if (!privileged && iflag) {
 165                 if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
 166                         state = 3;
 167                         read_profile(shinit);
 168                 }
 169         }
 170 state3:
 171         state = 4;
 172         popstackmark(&smark2);
 173         if (minusc) {
 174                 evalstring(minusc, sflag ? 0 : EV_EXIT);
 175         }
 176 state4:
 177         if (sflag || minusc == NULL) {
 178                 cmdloop(1);
 179         }
 180         exitshell(exitstatus);
 181         /*NOTREACHED*/
 182         return 0;
 183 }
 184
 185 static void
 186 reset(void)
 187 {
 188         reseteval();
 189         resetinput();
 190 }
 191
 192 /*
 193  * Read and execute commands.  "Top" is nonzero for the top level command
 194  * loop; it turns on prompting if the shell is interactive.
 195  */
 196
 197 static void
 198 cmdloop(int top)
 199 {
 200         union node *n;
 201         struct stackmark smark;
 202         int inter;
 203         int numeof = 0;
 204
 205         TRACE(("cmdloop(%d) called\n", top));
 206         setstackmark(&smark);
 207         for (;;) {
 208                 if (pendingsig)
 209                         dotrap();
 210                 inter = 0;
 211                 if (iflag && top) {
 212                         inter++;
 213                         showjobs(1, SHOWJOBS_DEFAULT);
 214                         chkmail(0);
 215                         flushout(&output);
 216                 }
 217                 n = parsecmd(inter);
 218                 /* showtree(n); DEBUG */
 219                 if (n == NEOF) {
 220                         if (!top || numeof >= 50)
 221                                 break;
 222                         if (!stoppedjobs()) {
 223                                 if (!Iflag)
 224                                         break;
 225                                 out2fmt_flush("\nUse \"exit\" to leave shell.\n");
 226                         }
 227                         numeof++;
 228                 } else if (n != NULL && nflag == 0) {
 229                         job_warning = (job_warning == 2) ? 1 : 0;
 230                         numeof = 0;
 231                         evaltree(n, 0);
 232                 }
 233                 popstackmark(&smark);
 234                 setstackmark(&smark);
 235                 if (evalskip != 0) {
 236                         if (evalskip == SKIPRETURN)
 237                                 evalskip = 0;
 238                         break;
 239                 }
 240         }
 241         popstackmark(&smark);
 242 }
 243
 244
 245
 246 /*
 247  * Read /etc/profile or .profile.  Return on error.
 248  */
 249
 250 static void
 251 read_profile(const char *name)
 252 {
 253         int fd;
 254         const char *expandedname;
 255
 256         expandedname = expandstr(name);
 257         if (expandedname == NULL)
 258                 return;
 259         INTOFF;
 260         if ((fd = open(expandedname, O_RDONLY | O_CLOEXEC_MAYBE)) >= 0)
 261                 setinputfd(fd, 1);
 262         INTON;
 263         if (fd < 0)
 264                 return;
 265         cmdloop(0);
 266         popfile();
 267 }
 268
 269
 270
 271 /*
 272  * Read a file containing shell functions.
 273  */
 274
 275 void
 276 readcmdfile(const char *name)
 277 {
 278         setinputfile(name, 1);
 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 char *
 292 find_dot_file(char *basename)
 293 {
 294         char *fullname;
 295         const char *path = pathval();
 296         struct stat statb;
 297
 298         /* don't try this for absolute or relative paths */
 299         if( strchr(basename, '/'))
 300                 return basename;
 301
 302         while ((fullname = padvance(&path, basename)) != NULL) {
 303                 if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
 304                         /*
 305                          * Don't bother freeing here, since it will
 306                          * be freed by the caller.
 307                          */
 308                         return fullname;
 309                 }
 310                 stunalloc(fullname);
 311         }
 312         return basename;
 313 }
 314
 315 int
 316 dotcmd(int argc, char **argv)
 317 {
 318         char *filename, *fullname;
 319
 320         if (argc < 2)
 321                 error("missing filename");
 322
 323         exitstatus = 0;
 324
 325         /*
 326          * Because we have historically not supported any options,
 327          * only treat "--" specially.
 328          */
 329         filename = argc > 2 && strcmp(argv[1], "--") == 0 ? argv[2] : argv[1];
 330
 331         fullname = find_dot_file(filename);
 332         setinputfile(fullname, 1);
 333         commandname = fullname;
 334         cmdloop(0);
 335         popfile();
 336         return exitstatus;
 337 }
 338
 339
 340 int
 341 exitcmd(int argc, char **argv)
 342 {
 343         if (stoppedjobs())
 344                 return 0;
 345         if (argc > 1)
 346                 exitshell(number(argv[1]));
 347         else
 348                 exitshell_savedstatus();
 349 }