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 1.49 2011/06/04 15:05:52 jilles Exp $
  39  */
  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 "init.h"
  66 #include "mystring.h"
  67 #include "exec.h"
  68 #include "cd.h"
  69
  70 int rootpid;
  71 int rootshell;
  72 struct jmploc main_handler;
  73 int localeisutf8, initial_localeisutf8;
  74
  75 static void read_profile(const char *);
  76 static const char *find_dot_file(const char *);
  77
  78 /*
  79  * Main routine.  We initialize things, parse the arguments, execute
  80  * profiles if we're a login shell, and then call cmdloop to execute
  81  * commands.  The setjmp call sets up the location to jump to when an
  82  * exception occurs.  When an exception occurs the variable "state"
  83  * is used to figure out how far we had gotten.
  84  */
  85
  86 int
  87 main(int argc, char *argv[])
  88 {
  89         struct stackmark smark;
  90         volatile int state;
  91         char *shinit;
  92
  93         setlocale(LC_ALL, "");
  94         initcharset();
  95         state = 0;
  96         if (setjmp(main_handler.loc)) {
  97                 switch (exception) {
  98                 case EXEXEC:
  99                         exitstatus = exerrno;
 100                         break;
 101
 102                 case EXERROR:
 103                         exitstatus = 2;
 104                         break;
 105
 106                 default:
 107                         break;
 108                 }
 109
 110                 if (state == 0 || iflag == 0 || ! rootshell ||
 111                     exception == EXEXIT)
 112                         exitshell(exitstatus);
 113                 reset();
 114                 if (exception == EXINT)
 115                         out2fmt_flush("\n");
 116                 popstackmark(&smark);
 117                 FORCEINTON;                             /* enable interrupts */
 118                 if (state == 1)
 119                         goto state1;
 120                 else if (state == 2)
 121                         goto state2;
 122                 else if (state == 3)
 123                         goto state3;
 124                 else
 125                         goto state4;
 126         }
 127         handler = &main_handler;
 128 #ifdef DEBUG
 129         opentrace();
 130         trputs("Shell args:  ");  trargs(argv);
 131 #endif
 132         rootpid = getpid();
 133         rootshell = 1;
 134         init();
 135         setstackmark(&smark);
 136         procargs(argc, argv);
 137         pwd_init(iflag);
 138         if (iflag)
 139                 chkmail(1);
 140         if (argv[0] && argv[0][0] == '-') {
 141                 state = 1;
 142                 read_profile("/etc/profile");
 143 state1:
 144                 state = 2;
 145                 if (privileged == 0)
 146                         read_profile(".profile");
 147                 else
 148                         read_profile("/etc/suid_profile");
 149         }
 150 state2:
 151         state = 3;
 152         if (!privileged && iflag) {
 153                 if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
 154                         state = 3;
 155                         read_profile(shinit);
 156                 }
 157         }
 158 state3:
 159         state = 4;
 160         if (minusc) {
 161                 evalstring(minusc, sflag ? 0 : EV_EXIT);
 162         }
 163         if (sflag || minusc == NULL) {
 164 state4: /* XXX ??? - why isn't this before the "if" statement */
 165                 cmdloop(1);
 166         }
 167         exitshell(exitstatus);
 168         /*NOTREACHED*/
 169         return 0;
 170 }
 171
 172
 173 /*
 174  * Read and execute commands.  "Top" is nonzero for the top level command
 175  * loop; it turns on prompting if the shell is interactive.
 176  */
 177
 178 void
 179 cmdloop(int top)
 180 {
 181         union node *n;
 182         struct stackmark smark;
 183         int inter;
 184         int numeof = 0;
 185
 186         TRACE(("cmdloop(%d) called\n", top));
 187         setstackmark(&smark);
 188         for (;;) {
 189                 if (pendingsigs)
 190                         dotrap();
 191                 inter = 0;
 192                 if (iflag && top) {
 193                         inter++;
 194                         showjobs(1, SHOWJOBS_DEFAULT);
 195                         chkmail(0);
 196                         flushout(&output);
 197                 }
 198                 n = parsecmd(inter);
 199                 /* showtree(n); DEBUG */
 200                 if (n == NEOF) {
 201                         if (!top || numeof >= 50)
 202                                 break;
 203                         if (!stoppedjobs()) {
 204                                 if (!Iflag)
 205                                         break;
 206                                 out2fmt_flush("\nUse \"exit\" to leave shell.\n");
 207                         }
 208                         numeof++;
 209                 } else if (n != NULL && nflag == 0) {
 210                         job_warning = (job_warning == 2) ? 1 : 0;
 211                         numeof = 0;
 212                         evaltree(n, 0);
 213                 }
 214                 popstackmark(&smark);
 215                 setstackmark(&smark);
 216                 if (evalskip != 0) {
 217                         if (evalskip == SKIPFILE)
 218                                 evalskip = 0;
 219                         break;
 220                 }
 221         }
 222         popstackmark(&smark);
 223 }
 224
 225
 226
 227 /*
 228  * Read /etc/profile or .profile.  Return on error.
 229  */
 230
 231 static void
 232 read_profile(const char *name)
 233 {
 234         int fd;
 235
 236         INTOFF;
 237         if ((fd = open(name, O_RDONLY)) >= 0)
 238                 setinputfd(fd, 1);
 239         INTON;
 240         if (fd < 0)
 241                 return;
 242         cmdloop(0);
 243         popfile();
 244 }
 245
 246
 247
 248 /*
 249  * Read a file containing shell functions.
 250  */
 251
 252 void
 253 readcmdfile(const char *name)
 254 {
 255         int fd;
 256
 257         INTOFF;
 258         if ((fd = open(name, O_RDONLY)) >= 0)
 259                 setinputfd(fd, 1);
 260         else
 261                 error("cannot open %s: %s", name, strerror(errno));
 262         INTON;
 263         cmdloop(0);
 264         popfile();
 265 }
 266
 267
 268
 269 /*
 270  * Take commands from a file.  To be compatible we should do a path
 271  * search for the file, which is necessary to find sub-commands.
 272  */
 273
 274
 275 static const char *
 276 find_dot_file(const char *basename)
 277 {
 278         char *fullname;
 279         const char *path = pathval();
 280         struct stat statb;
 281
 282         /* don't try this for absolute or relative paths */
 283         if( strchr(basename, '/'))
 284                 return basename;
 285
 286         while ((fullname = padvance(&path, basename)) != NULL) {
 287                 if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
 288                         /*
 289                          * Don't bother freeing here, since it will
 290                          * be freed by the caller.
 291                          */
 292                         return fullname;
 293                 }
 294                 stunalloc(fullname);
 295         }
 296         return basename;
 297 }
 298
 299 int
 300 dotcmd(int argc, char **argv)
 301 {
 302         const char *fullname;
 303         char *filename;
 304
 305         if (argc < 2)
 306                 error("missing filename");
 307
 308         exitstatus = 0;
 309
 310         /*
 311          * Because we have historically not supported any options,
 312          * only treat "--" specially.
 313          */
 314         filename = argc > 2 && strcmp(argv[1], "--") == 0 ? argv[2] : argv[1];
 315
 316         fullname = find_dot_file(filename);
 317         setinputfile(fullname, 1);
 318         commandname = fullname;
 319         cmdloop(0);
 320         popfile();
 321         return exitstatus;
 322 }
 323
 324
 325 int
 326 exitcmd(int argc, char **argv)
 327 {
 328         if (stoppedjobs())
 329                 return 0;
 330         if (argc > 1)
 331                 exitshell(number(argv[1]));
 332         else
 333                 exitshell_savedstatus();
 334 }