2 * Copyright (c) 2008, 2009, 2010, 2011, 2013, 2014 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"
22 #include "dynamic-string.h"
23 #include "ovs-thread.h"
27 VLOG_DEFINE_THIS_MODULE(command_line);
29 /* Given the GNU-style long options in 'options', returns a string that may be
30 * passed to getopt() with the corresponding short options. The caller is
31 * responsible for freeing the string. */
33 long_options_to_short_options(const struct option options[])
35 char short_options[UCHAR_MAX * 3 + 1];
36 char *p = short_options;
38 for (; options->name; options++) {
39 const struct option *o = options;
40 if (o->flag == NULL && o->val > 0 && o->val <= UCHAR_MAX) {
42 if (o->has_arg == required_argument) {
44 } else if (o->has_arg == optional_argument) {
52 return xstrdup(short_options);
55 /* Given the 'struct command' array, prints the usage of all commands. */
57 print_commands(const struct command commands[])
59 struct ds ds = DS_EMPTY_INITIALIZER;
61 ds_put_cstr(&ds, "The available commands are:\n");
62 for (; commands->name; commands++) {
63 const struct command *c = commands;
64 ds_put_format(&ds, " %-23s %s\n", c->name, c->usage ? c->usage : "");
66 printf("%s", ds.string);
70 /* Given the GNU-style options in 'options', prints all options. */
72 print_options(const struct option options[])
74 struct ds ds = DS_EMPTY_INITIALIZER;
76 for (; options->name; options++) {
77 const struct option *o = options;
78 const char *arg = o->has_arg == required_argument ? "ARG" : "[ARG]";
80 ds_put_format(&ds, "--%s%s%s\n", o->name, o->has_arg ? "=" : "",
81 o->has_arg ? arg : "");
82 if (o->flag == NULL && o->val > 0 && o->val <= UCHAR_MAX) {
83 ds_put_format(&ds, "-%c %s\n", o->val, o->has_arg ? arg : "");
86 printf("%s", ds.string);
90 /* Runs the command designated by argv[0] within the command table specified by
91 * 'commands', which must be terminated by a command whose 'name' member is a
94 * Command-line options should be stripped off, so that a typical invocation
95 * looks like "run_command(argc - optind, argv + optind, my_commands);". */
97 run_command(int argc, char *argv[], const struct command commands[])
99 const struct command *p;
102 ovs_fatal(0, "missing command name; use --help for help");
105 for (p = commands; p->name != NULL; p++) {
106 if (!strcmp(p->name, argv[0])) {
107 int n_arg = argc - 1;
108 if (n_arg < p->min_args) {
109 VLOG_FATAL( "'%s' command requires at least %d arguments",
110 p->name, p->min_args);
111 } else if (n_arg > p->max_args) {
112 VLOG_FATAL("'%s' command takes at most %d arguments",
113 p->name, p->max_args);
115 p->handler(argc, argv);
116 if (ferror(stdout)) {
117 VLOG_FATAL("write to stdout failed");
119 if (ferror(stderr)) {
120 VLOG_FATAL("write to stderr failed");
127 VLOG_FATAL("unknown command '%s'; use --help for help", argv[0]);
133 static struct ovs_mutex proctitle_mutex = OVS_MUTEX_INITIALIZER;
135 /* Start of command-line arguments in memory. */
136 static char *argv_start OVS_GUARDED_BY(proctitle_mutex);
138 /* Number of bytes of command-line arguments. */
139 static size_t argv_size OVS_GUARDED_BY(proctitle_mutex);
141 /* Saved command-line arguments. */
142 static char *saved_proctitle OVS_GUARDED_BY(proctitle_mutex);
144 /* Prepares the process so that proctitle_set() can later succeed.
146 * This modifies the argv[] array so that it no longer points into the memory
147 * that it originally does. Later, proctitle_set() might overwrite that
148 * memory. That means that this function should be called before anything else
149 * that accesses the process's argv[] array. Ideally, it should be called
150 * before anything else, period, at the very beginning of program
153 proctitle_init(int argc, char **argv)
157 assert_single_threaded();
158 if (!argc || !argv[0]) {
159 /* This situation should never occur, but... */
163 ovs_mutex_lock(&proctitle_mutex);
164 /* Specialized version of first loop iteration below. */
165 argv_start = argv[0];
166 argv_size = strlen(argv[0]) + 1;
167 argv[0] = xstrdup(argv[0]);
169 for (i = 1; i < argc; i++) {
170 size_t size = strlen(argv[i]) + 1;
172 /* Add (argv[i], strlen(argv[i])+1) to (argv_start, argv_size). */
173 if (argv[i] + size == argv_start) {
174 /* Arguments grow downward in memory. */
177 } else if (argv[i] == argv_start + argv_size) {
178 /* Arguments grow upward in memory. */
181 /* Arguments not contiguous. (Is this really Linux?) */
184 /* Copy out the old argument so we can reuse the space. */
185 argv[i] = xstrdup(argv[i]);
187 ovs_mutex_unlock(&proctitle_mutex);
190 /* Changes the name of the process, as shown by "ps", to the program name
191 * followed by 'format', which is formatted as if by printf(). */
193 proctitle_set(const char *format, ...)
198 ovs_mutex_lock(&proctitle_mutex);
199 if (!argv_start || argv_size < 8) {
203 if (!saved_proctitle) {
204 saved_proctitle = xmemdup(argv_start, argv_size);
207 va_start(args, format);
208 n = snprintf(argv_start, argv_size, "%s: ", program_name);
210 n += vsnprintf(argv_start + n, argv_size - n, format, args);
212 if (n >= argv_size) {
213 /* The name is too long, so add an ellipsis at the end. */
214 strcpy(&argv_start[argv_size - 4], "...");
216 /* Fill the extra space with null bytes, so that trailing bytes don't
217 * show up in the command line. */
218 memset(&argv_start[n], '\0', argv_size - n);
223 ovs_mutex_unlock(&proctitle_mutex);
226 /* Restores the process's original command line, as seen by "ps". */
228 proctitle_restore(void)
230 ovs_mutex_lock(&proctitle_mutex);
231 if (saved_proctitle) {
232 memcpy(argv_start, saved_proctitle, argv_size);
233 free(saved_proctitle);
234 saved_proctitle = NULL;
236 ovs_mutex_unlock(&proctitle_mutex);
238 #else /* !__linux__ */
239 /* Stubs that don't do anything on non-Linux systems. */
242 proctitle_init(int argc OVS_UNUSED, char **argv OVS_UNUSED)
246 #if !(defined(__FreeBSD__) || defined(__NetBSD__))
247 /* On these platforms we #define this to setproctitle. */
249 proctitle_set(const char *format OVS_UNUSED, ...)
255 proctitle_restore(void)
258 #endif /* !__linux__ */