2 * Copyright (c) 2008, 2009, 2010, 2011 Nicira, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
18 #include "command-line.h"
25 VLOG_DEFINE_THIS_MODULE(command_line);
27 /* Given the GNU-style long options in 'options', returns a string that may be
28 * passed to getopt() with the corresponding short options. The caller is
29 * responsible for freeing the string. */
31 long_options_to_short_options(const struct option options[])
33 char short_options[UCHAR_MAX * 3 + 1];
34 char *p = short_options;
36 for (; options->name; options++) {
37 const struct option *o = options;
38 if (o->flag == NULL && o->val > 0 && o->val <= UCHAR_MAX) {
40 if (o->has_arg == required_argument) {
42 } else if (o->has_arg == optional_argument) {
50 return xstrdup(short_options);
53 /* Runs the command designated by argv[0] within the command table specified by
54 * 'commands', which must be terminated by a command whose 'name' member is a
57 * Command-line options should be stripped off, so that a typical invocation
58 * looks like "run_command(argc - optind, argv + optind, my_commands);". */
60 run_command(int argc, char *argv[], const struct command commands[])
62 const struct command *p;
65 ovs_fatal(0, "missing command name; use --help for help");
68 for (p = commands; p->name != NULL; p++) {
69 if (!strcmp(p->name, argv[0])) {
71 if (n_arg < p->min_args) {
72 VLOG_FATAL( "'%s' command requires at least %d arguments",
73 p->name, p->min_args);
74 } else if (n_arg > p->max_args) {
75 VLOG_FATAL("'%s' command takes at most %d arguments",
76 p->name, p->max_args);
78 p->handler(argc, argv);
80 VLOG_FATAL("write to stdout failed");
83 VLOG_FATAL("write to stderr failed");
90 VLOG_FATAL("unknown command '%s'; use --help for help", argv[0]);
96 static char *argv_start; /* Start of command-line arguments in memory. */
97 static size_t argv_size; /* Number of bytes of command-line arguments. */
98 static char *saved_proctitle; /* Saved command-line arguments. */
100 /* Prepares the process so that proctitle_set() can later succeed.
102 * This modifies the argv[] array so that it no longer points into the memory
103 * that it originally does. Later, proctitle_set() might overwrite that
104 * memory. That means that this function should be called before anything else
105 * that accesses the process's argv[] array. Ideally, it should be called
106 * before anything else, period, at the very beginning of program
109 proctitle_init(int argc, char **argv)
113 if (!argc || !argv[0]) {
114 /* This situation should never occur, but... */
118 /* Specialized version of first loop iteration below. */
119 argv_start = argv[0];
120 argv_size = strlen(argv[0]) + 1;
121 argv[0] = xstrdup(argv[0]);
123 for (i = 1; i < argc; i++) {
124 size_t size = strlen(argv[i]) + 1;
126 /* Add (argv[i], strlen(argv[i])+1) to (argv_start, argv_size). */
127 if (argv[i] + size == argv_start) {
128 /* Arguments grow downward in memory. */
131 } else if (argv[i] == argv_start + argv_size) {
132 /* Arguments grow upward in memory. */
135 /* Arguments not contiguous. (Is this really Linux?) */
138 /* Copy out the old argument so we can reuse the space. */
139 argv[i] = xstrdup(argv[i]);
143 /* Changes the name of the process, as shown by "ps", to the program name
144 * followed by 'format', which is formatted as if by printf(). */
146 proctitle_set(const char *format, ...)
151 if (!argv_start || argv_size < 8) {
155 if (!saved_proctitle) {
156 saved_proctitle = xmemdup(argv_start, argv_size);
159 va_start(args, format);
160 n = snprintf(argv_start, argv_size, "%s: ", program_name);
162 n += vsnprintf(argv_start + n, argv_size - n, format, args);
164 if (n >= argv_size) {
165 /* The name is too long, so add an ellipsis at the end. */
166 strcpy(&argv_start[argv_size - 4], "...");
168 /* Fill the extra space with null bytes, so that trailing bytes don't
169 * show up in the command line. */
170 memset(&argv_start[n], '\0', argv_size - n);
175 /* Restores the process's original command line, as seen by "ps". */
177 proctitle_restore(void)
179 if (saved_proctitle) {
180 memcpy(argv_start, saved_proctitle, argv_size);
181 free(saved_proctitle);
182 saved_proctitle = NULL;
185 #else /* !LINUX_DATAPATH*/
186 /* Stubs that don't do anything on non-Linux systems. */
189 proctitle_init(int argc OVS_UNUSED, char **argv OVS_UNUSED)
194 /* On FreeBSD we #define this to setproctitle. */
196 proctitle_set(const char *format OVS_UNUSED, ...)
202 proctitle_restore(void)
205 #endif /* !LINUX_DATAPATH */