usr/src/cmd/runat/runat.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2001 by Sun Microsystems, Inc.
  24  * All rights reserved.
  25  */
  26
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28
  29 /*
  30  * runat: run a command in attribute directory.
  31  *
  32  * runat file [command]
  33  *
  34  * when command is not specified an interactive shell is started
  35  * in the attribute directory.
  36  */
  37
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include <unistd.h>
  41 #include <fcntl.h>
  42 #include <libintl.h>
  43 #include <errno.h>
  44 #include <strings.h>
  45
  46 static void
  47 usage()
  48 {
  49         (void) fprintf(stderr, gettext("usage: runat filename [command]\n"));
  50 }
  51
  52 int
  53 main(int argc, char *argv[])
  54 {
  55         int fd;
  56         int dirfd;
  57         int i;
  58         int argslen;
  59         char *shell;
  60         char *args[4];
  61         char *cmdargs;
  62
  63         if (argc < 2) {
  64                 usage();
  65                 exit(127);
  66         }
  67
  68         if ((fd = open64(argv[1], O_RDONLY)) == -1) {
  69                 (void) fprintf(stderr,
  70                     gettext("runat: cannot open %s: %s\n"), argv[1],
  71                     strerror(errno));
  72                 exit(125);
  73         }
  74
  75         if ((dirfd = openat64(fd, ".", O_RDONLY|O_XATTR)) == -1) {
  76                 (void) fprintf(stderr,
  77                     gettext("runat: cannot open attribute"
  78                     " directory for %s: %s\n"), argv[1], strerror(errno));
  79                 exit(125);
  80         }
  81
  82         (void) close(fd);
  83
  84         if (fchdir(dirfd) == -1) {
  85                 (void) fprintf(stderr,
  86                     gettext("runat: cannot fchdir to attribute"
  87                     " directory: %s\n"), strerror(errno));
  88                 exit(125);
  89         }
  90
  91         if (argc < 3) {
  92                 shell = getenv("SHELL");
  93                 if (shell == NULL) {
  94                         (void) fprintf(stderr,
  95                             gettext(
  96                             "runat: shell not found, using /bin/sh\n"));
  97                         shell = "/bin/sh";
  98                 }
  99
 100                 (void) execl(shell, shell, NULL);
 101                 (void) fprintf(stderr,
 102                     gettext("runat: Failed to exec %s: %s\n"), shell,
 103                     strerror(errno));
 104                 return (126);
 105         }
 106
 107         /*
 108          * Count up the size of all of the args
 109          */
 110
 111         for (i = 2, argslen = 0; i < argc; i++) {
 112                 argslen += strlen(argv[i]) + 1;
 113         }
 114
 115         cmdargs = calloc(1, argslen);
 116         if (cmdargs == NULL) {
 117                 (void) fprintf(stderr, gettext(
 118                     "runat: failed to allocate memory for"
 119                     " command arguments: %s\n"), strerror(errno));
 120                 exit(126);
 121         }
 122
 123
 124         /*
 125          * create string with all of the args concatenated together
 126          * This is done so that the shell will interpret the args
 127          * and do globbing if necessary.
 128          */
 129         for (i = 2; i < argc; i++) {
 130                 if (strlcat(cmdargs, argv[i], argslen) >= argslen) {
 131                         (void) fprintf(stderr, gettext(
 132                             "runat: arguments won't fit in"
 133                             " allocated buffer\n"));
 134                         exit(126);
 135                 }
 136
 137                 /*
 138                  * tack on a space if there are more args
 139                  */
 140                 if ((i + 1) < argc) {
 141                         if (strlcat(cmdargs, " ", argslen) >= argslen) {
 142                                 (void) fprintf(stderr, gettext(
 143                                     "runat: arguments won't fit in"
 144                                     " allocated buffer\n"));
 145                                 exit(126);
 146                         }
 147                 }
 148
 149         }
 150
 151         args[0] = "/bin/sh";
 152         args[1] = "-c";
 153         args[2] = cmdargs;
 154         args[3] = NULL;
 155         (void) execvp(args[0], args);
 156         (void) fprintf(stderr, gettext("runat: Failed to exec %s: %s\n"),
 157             argv[0], strerror(errno));
 158         return (126);
 159 }