1 /* 2 * (C) Copyright 2000-2008 3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de. 4 * 5 * SPDX-License-Identifier: GPL-2.0+ 6 */ 7 8 /* 9 * Command line user interface to firmware (=U-Boot) environment. 10 * 11 * Implements: 12 * fw_printenv [[ -n name ] | [ name ... ]] 13 * - prints the value of a single environment variable 14 * "name", the ``name=value'' pairs of one or more 15 * environment variables "name", or the whole 16 * environment if no names are specified. 17 * fw_setenv name [ value ... ] 18 * - If a name without any values is given, the variable 19 * with this name is deleted from the environment; 20 * otherwise, all "value" arguments are concatenated, 21 * separated by single blank characters, and the 22 * resulting string is assigned to the environment 23 * variable "name" 24 */ 25 26 #include <fcntl.h> 27 #include <getopt.h> 28 #include <stdio.h> 29 #include <string.h> 30 #include <stdlib.h> 31 #include <sys/file.h> 32 #include <unistd.h> 33 #include "fw_env.h" 34 35 #define CMD_PRINTENV "fw_printenv" 36 #define CMD_SETENV "fw_setenv" 37 38 static struct option long_options[] = { 39 {"script", required_argument, NULL, 's'}, 40 {"help", no_argument, NULL, 'h'}, 41 {NULL, 0, NULL, 0} 42 }; 43 44 void usage(void) 45 { 46 47 fprintf(stderr, "fw_printenv/fw_setenv, " 48 "a command line interface to U-Boot environment\n\n" 49 "usage:\tfw_printenv [-n] [variable name]\n" 50 "\tfw_setenv [variable name] [variable value]\n" 51 "\tfw_setenv -s [ file ]\n" 52 "\tfw_setenv -s - < [ file ]\n\n" 53 "The file passed as argument contains only pairs " 54 "name / value\n" 55 "Example:\n" 56 "# Any line starting with # is treated as comment\n" 57 "\n" 58 "\t netdev eth0\n" 59 "\t kernel_addr 400000\n" 60 "\t var1\n" 61 "\t var2 The quick brown fox jumps over the " 62 "lazy dog\n" 63 "\n" 64 "A variable without value will be dropped. It is possible\n" 65 "to put any number of spaces between the fields, but any\n" 66 "space inside the value is treated as part of the value " 67 "itself.\n\n" 68 ); 69 } 70 71 int main(int argc, char *argv[]) 72 { 73 char *p; 74 char *cmdname = *argv; 75 char *script_file = NULL; 76 int c; 77 const char *lockname = "/var/lock/" CMD_PRINTENV ".lock"; 78 int lockfd = -1; 79 int retval = EXIT_SUCCESS; 80 81 lockfd = open(lockname, O_WRONLY | O_CREAT | O_TRUNC, 0666); 82 if (-1 == lockfd) { 83 fprintf(stderr, "Error opening lock file %s\n", lockname); 84 return EXIT_FAILURE; 85 } 86 87 if (-1 == flock(lockfd, LOCK_EX)) { 88 fprintf(stderr, "Error locking file %s\n", lockname); 89 close(lockfd); 90 return EXIT_FAILURE; 91 } 92 93 if ((p = strrchr (cmdname, '/')) != NULL) { 94 cmdname = p + 1; 95 } 96 97 while ((c = getopt_long (argc, argv, "ns:h", 98 long_options, NULL)) != EOF) { 99 switch (c) { 100 case 'n': 101 /* handled in fw_printenv */ 102 break; 103 case 's': 104 script_file = optarg; 105 break; 106 case 'h': 107 usage(); 108 goto exit; 109 default: /* '?' */ 110 fprintf(stderr, "Try `%s --help' for more information." 111 "\n", cmdname); 112 retval = EXIT_FAILURE; 113 goto exit; 114 } 115 } 116 117 if (strcmp(cmdname, CMD_PRINTENV) == 0) { 118 if (fw_printenv(argc, argv) != 0) 119 retval = EXIT_FAILURE; 120 } else if (strcmp(cmdname, CMD_SETENV) == 0) { 121 if (!script_file) { 122 if (fw_setenv(argc, argv) != 0) 123 retval = EXIT_FAILURE; 124 } else { 125 if (fw_parse_script(script_file) != 0) 126 retval = EXIT_FAILURE; 127 } 128 } else { 129 fprintf(stderr, 130 "Identity crisis - may be called as `" CMD_PRINTENV 131 "' or as `" CMD_SETENV "' but not as `%s'\n", 132 cmdname); 133 retval = EXIT_FAILURE; 134 } 135 136 exit: 137 flock(lockfd, LOCK_UN); 138 close(lockfd); 139 return retval; 140 } 141