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"
25 #include "openvswitch/vlog.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 ovs_cmdl_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 ovs_cmdl_command' array, prints the usage of all commands. */
57 ovs_cmdl_print_commands(const struct ovs_cmdl_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 ovs_cmdl_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 ovs_cmdl_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
96 * struct ovs_cmdl_context ctx = {
97 * .argc = argc - optind,
98 * .argv = argv + optind,
100 * ovs_cmdl_run_command(&ctx, my_commands);
103 ovs_cmdl_run_command(struct ovs_cmdl_context *ctx, const struct ovs_cmdl_command commands[])
105 const struct ovs_cmdl_command *p;
108 ovs_fatal(0, "missing command name; use --help for help");
111 for (p = commands; p->name != NULL; p++) {
112 if (!strcmp(p->name, ctx->argv[0])) {
113 int n_arg = ctx->argc - 1;
114 if (n_arg < p->min_args) {
115 VLOG_FATAL( "'%s' command requires at least %d arguments",
116 p->name, p->min_args);
117 } else if (n_arg > p->max_args) {
118 VLOG_FATAL("'%s' command takes at most %d arguments",
119 p->name, p->max_args);
122 if (ferror(stdout)) {
123 VLOG_FATAL("write to stdout failed");
125 if (ferror(stderr)) {
126 VLOG_FATAL("write to stderr failed");
133 VLOG_FATAL("unknown command '%s'; use --help for help", ctx->argv[0]);
139 static struct ovs_mutex proctitle_mutex = OVS_MUTEX_INITIALIZER;
141 /* Start of command-line arguments in memory. */
142 static char *argv_start OVS_GUARDED_BY(proctitle_mutex);
144 /* Number of bytes of command-line arguments. */
145 static size_t argv_size OVS_GUARDED_BY(proctitle_mutex);
147 /* Saved command-line arguments. */
148 static char *saved_proctitle OVS_GUARDED_BY(proctitle_mutex);
150 /* Prepares the process so that proctitle_set() can later succeed.
152 * This modifies the argv[] array so that it no longer points into the memory
153 * that it originally does. Later, proctitle_set() might overwrite that
154 * memory. That means that this function should be called before anything else
155 * that accesses the process's argv[] array. Ideally, it should be called
156 * before anything else, period, at the very beginning of program
159 ovs_cmdl_proctitle_init(int argc, char **argv)
163 assert_single_threaded();
164 if (!argc || !argv[0]) {
165 /* This situation should never occur, but... */
169 ovs_mutex_lock(&proctitle_mutex);
170 /* Specialized version of first loop iteration below. */
171 argv_start = argv[0];
172 argv_size = strlen(argv[0]) + 1;
173 argv[0] = xstrdup(argv[0]);
175 for (i = 1; i < argc; i++) {
176 size_t size = strlen(argv[i]) + 1;
178 /* Add (argv[i], strlen(argv[i])+1) to (argv_start, argv_size). */
179 if (argv[i] + size == argv_start) {
180 /* Arguments grow downward in memory. */
183 } else if (argv[i] == argv_start + argv_size) {
184 /* Arguments grow upward in memory. */
187 /* Arguments not contiguous. (Is this really Linux?) */
190 /* Copy out the old argument so we can reuse the space. */
191 argv[i] = xstrdup(argv[i]);
193 ovs_mutex_unlock(&proctitle_mutex);
196 /* Changes the name of the process, as shown by "ps", to the program name
197 * followed by 'format', which is formatted as if by printf(). */
199 ovs_cmdl_proctitle_set(const char *format, ...)
204 ovs_mutex_lock(&proctitle_mutex);
205 if (!argv_start || argv_size < 8) {
209 if (!saved_proctitle) {
210 saved_proctitle = xmemdup(argv_start, argv_size);
213 va_start(args, format);
214 n = snprintf(argv_start, argv_size, "%s: ", program_name);
216 n += vsnprintf(argv_start + n, argv_size - n, format, args);
218 if (n >= argv_size) {
219 /* The name is too long, so add an ellipsis at the end. */
220 strcpy(&argv_start[argv_size - 4], "...");
222 /* Fill the extra space with null bytes, so that trailing bytes don't
223 * show up in the command line. */
224 memset(&argv_start[n], '\0', argv_size - n);
229 ovs_mutex_unlock(&proctitle_mutex);
232 /* Restores the process's original command line, as seen by "ps". */
234 ovs_cmdl_proctitle_restore(void)
236 ovs_mutex_lock(&proctitle_mutex);
237 if (saved_proctitle) {
238 memcpy(argv_start, saved_proctitle, argv_size);
239 free(saved_proctitle);
240 saved_proctitle = NULL;
242 ovs_mutex_unlock(&proctitle_mutex);
244 #else /* !__linux__ */
245 /* Stubs that don't do anything on non-Linux systems. */
248 ovs_cmdl_proctitle_init(int argc OVS_UNUSED, char **argv OVS_UNUSED)
252 #if !(defined(__FreeBSD__) || defined(__NetBSD__))
253 /* On these platforms we #define this to setproctitle. */
255 ovs_cmdl_proctitle_set(const char *format OVS_UNUSED, ...)
261 ovs_cmdl_proctitle_restore(void)
264 #endif /* !__linux__ */