tools/env/fw_env_main.c

   1 /*
   2  * (C) Copyright 2000-2008
   3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4  *
   5  * See file CREDITS for list of people who contributed to this
   6  * project.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation; either version 2 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21  * MA 02111-1307 USA
  22  */
  23
  24 /*
  25  * Command line user interface to firmware (=U-Boot) environment.
  26  *
  27  * Implements:
  28  *      fw_printenv [[ -n name ] | [ name ... ]]
  29  *              - prints the value of a single environment variable
  30  *                "name", the ``name=value'' pairs of one or more
  31  *                environment variables "name", or the whole
  32  *                environment if no names are specified.
  33  *      fw_setenv name [ value ... ]
  34  *              - If a name without any values is given, the variable
  35  *                with this name is deleted from the environment;
  36  *                otherwise, all "value" arguments are concatenated,
  37  *                separated by single blank characters, and the
  38  *                resulting string is assigned to the environment
  39  *                variable "name"
  40  */
  41
  42 #include <fcntl.h>
  43 #include <getopt.h>
  44 #include <stdio.h>
  45 #include <string.h>
  46 #include <stdlib.h>
  47 #include <sys/file.h>
  48 #include <unistd.h>
  49 #include "fw_env.h"
  50
  51 #define CMD_PRINTENV    "fw_printenv"
  52 #define CMD_SETENV      "fw_setenv"
  53
  54 static struct option long_options[] = {
  55         {"script", required_argument, NULL, 's'},
  56         {"help", no_argument, NULL, 'h'},
  57         {NULL, 0, NULL, 0}
  58 };
  59
  60 void usage(void)
  61 {
  62
  63         fprintf(stderr, "fw_printenv/fw_setenv, "
  64                 "a command line interface to U-Boot environment\n\n"
  65                 "usage:\tfw_printenv [-n] [variable name]\n"
  66                 "\tfw_setenv [variable name] [variable value]\n"
  67                 "\tfw_setenv -s [ file ]\n"
  68                 "\tfw_setenv -s - < [ file ]\n\n"
  69                 "The file passed as argument contains only pairs "
  70                 "name / value\n"
  71                 "Example:\n"
  72                 "# Any line starting with # is treated as comment\n"
  73                 "\n"
  74                 "\t      netdev         eth0\n"
  75                 "\t      kernel_addr    400000\n"
  76                 "\t      var1\n"
  77                 "\t      var2          The quick brown fox jumps over the "
  78                 "lazy dog\n"
  79                 "\n"
  80                 "A variable without value will be dropped. It is possible\n"
  81                 "to put any number of spaces between the fields, but any\n"
  82                 "space inside the value is treated as part of the value "
  83                 "itself.\n\n"
  84         );
  85 }
  86
  87 int main(int argc, char *argv[])
  88 {
  89         char *p;
  90         char *cmdname = *argv;
  91         char *script_file = NULL;
  92         int c;
  93         const char *lockname = "/var/lock/" CMD_PRINTENV ".lock";
  94         int lockfd = -1;
  95         int retval = EXIT_SUCCESS;
  96
  97         lockfd = open(lockname, O_WRONLY | O_CREAT | O_TRUNC);
  98         if (-1 == lockfd) {
  99                 fprintf(stderr, "Error opening lock file %s\n", lockname);
 100                 return EXIT_FAILURE;
 101         }
 102
 103         if (-1 == flock(lockfd, LOCK_EX)) {
 104                 fprintf(stderr, "Error locking file %s\n", lockname);
 105                 close(lockfd);
 106                 return EXIT_FAILURE;
 107         }
 108
 109         if ((p = strrchr (cmdname, '/')) != NULL) {
 110                 cmdname = p + 1;
 111         }
 112
 113         while ((c = getopt_long (argc, argv, "ns:h",
 114                 long_options, NULL)) != EOF) {
 115                 switch (c) {
 116                 case 'n':
 117                         /* handled in fw_printenv */
 118                         break;
 119                 case 's':
 120                         script_file = optarg;
 121                         break;
 122                 case 'h':
 123                         usage();
 124                         goto exit;
 125                 default: /* '?' */
 126                         fprintf(stderr, "Try `%s --help' for more information."
 127                                 "\n", cmdname);
 128                         retval = EXIT_FAILURE;
 129                         goto exit;
 130                 }
 131         }
 132
 133         if (strcmp(cmdname, CMD_PRINTENV) == 0) {
 134                 if (fw_printenv(argc, argv) != 0)
 135                         retval = EXIT_FAILURE;
 136         } else if (strcmp(cmdname, CMD_SETENV) == 0) {
 137                 if (!script_file) {
 138                         if (fw_setenv(argc, argv) != 0)
 139                                 retval = EXIT_FAILURE;
 140                 } else {
 141                         if (fw_parse_script(script_file) != 0)
 142                                 retval = EXIT_FAILURE;
 143                 }
 144         } else {
 145                 fprintf(stderr,
 146                         "Identity crisis - may be called as `" CMD_PRINTENV
 147                         "' or as `" CMD_SETENV "' but not as `%s'\n",
 148                         cmdname);
 149                 retval = EXIT_FAILURE;
 150         }
 151
 152 exit:
 153         flock(lockfd, LOCK_UN);
 154         close(lockfd);
 155         return retval;
 156 }