xref: /openbmc/u-boot/tools/env/fw_env_main.c (revision 522de019)
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 }
157