2 * Copyright (c) 2008, 2009, 2010, 2011, 2013 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 "ovs-thread.h"
26 VLOG_DEFINE_THIS_MODULE(command_line);
28 /* Given the GNU-style long options in 'options', returns a string that may be
29 * passed to getopt() with the corresponding short options. The caller is
30 * responsible for freeing the string. */
32 long_options_to_short_options(const struct option options[])
34 char short_options[UCHAR_MAX * 3 + 1];
35 char *p = short_options;
37 for (; options->name; options++) {
38 const struct option *o = options;
39 if (o->flag == NULL && o->val > 0 && o->val <= UCHAR_MAX) {
41 if (o->has_arg == required_argument) {
43 } else if (o->has_arg == optional_argument) {
51 return xstrdup(short_options);
54 /* Runs the command designated by argv[0] within the command table specified by
55 * 'commands', which must be terminated by a command whose 'name' member is a
58 * Command-line options should be stripped off, so that a typical invocation
59 * looks like "run_command(argc - optind, argv + optind, my_commands);". */
61 run_command(int argc, char *argv[], const struct command commands[])
63 const struct command *p;
66 ovs_fatal(0, "missing command name; use --help for help");
69 for (p = commands; p->name != NULL; p++) {
70 if (!strcmp(p->name, argv[0])) {
72 if (n_arg < p->min_args) {
73 VLOG_FATAL( "'%s' command requires at least %d arguments",
74 p->name, p->min_args);
75 } else if (n_arg > p->max_args) {
76 VLOG_FATAL("'%s' command takes at most %d arguments",
77 p->name, p->max_args);
79 p->handler(argc, argv);
81 VLOG_FATAL("write to stdout failed");
84 VLOG_FATAL("write to stderr failed");
91 VLOG_FATAL("unknown command '%s'; use --help for help", argv[0]);
97 static struct ovs_mutex proctitle_mutex = OVS_MUTEX_INITIALIZER;
99 /* Start of command-line arguments in memory. */
100 static char *argv_start OVS_GUARDED_BY(proctitle_mutex);
102 /* Number of bytes of command-line arguments. */
103 static size_t argv_size OVS_GUARDED_BY(proctitle_mutex);
105 /* Saved command-line arguments. */
106 static char *saved_proctitle OVS_GUARDED_BY(proctitle_mutex);
108 /* Prepares the process so that proctitle_set() can later succeed.
110 * This modifies the argv[] array so that it no longer points into the memory
111 * that it originally does. Later, proctitle_set() might overwrite that
112 * memory. That means that this function should be called before anything else
113 * that accesses the process's argv[] array. Ideally, it should be called
114 * before anything else, period, at the very beginning of program
117 proctitle_init(int argc, char **argv)
121 assert_single_threaded();
122 if (!argc || !argv[0]) {
123 /* This situation should never occur, but... */
127 ovs_mutex_lock(&proctitle_mutex);
128 /* Specialized version of first loop iteration below. */
129 argv_start = argv[0];
130 argv_size = strlen(argv[0]) + 1;
131 argv[0] = xstrdup(argv[0]);
133 for (i = 1; i < argc; i++) {
134 size_t size = strlen(argv[i]) + 1;
136 /* Add (argv[i], strlen(argv[i])+1) to (argv_start, argv_size). */
137 if (argv[i] + size == argv_start) {
138 /* Arguments grow downward in memory. */
141 } else if (argv[i] == argv_start + argv_size) {
142 /* Arguments grow upward in memory. */
145 /* Arguments not contiguous. (Is this really Linux?) */
148 /* Copy out the old argument so we can reuse the space. */
149 argv[i] = xstrdup(argv[i]);
151 ovs_mutex_unlock(&proctitle_mutex);
154 /* Changes the name of the process, as shown by "ps", to the program name
155 * followed by 'format', which is formatted as if by printf(). */
157 proctitle_set(const char *format, ...)
162 ovs_mutex_lock(&proctitle_mutex);
163 if (!argv_start || argv_size < 8) {
167 if (!saved_proctitle) {
168 saved_proctitle = xmemdup(argv_start, argv_size);
171 va_start(args, format);
172 n = snprintf(argv_start, argv_size, "%s: ", program_name);
174 n += vsnprintf(argv_start + n, argv_size - n, format, args);
176 if (n >= argv_size) {
177 /* The name is too long, so add an ellipsis at the end. */
178 strcpy(&argv_start[argv_size - 4], "...");
180 /* Fill the extra space with null bytes, so that trailing bytes don't
181 * show up in the command line. */
182 memset(&argv_start[n], '\0', argv_size - n);
187 ovs_mutex_unlock(&proctitle_mutex);
190 /* Restores the process's original command line, as seen by "ps". */
192 proctitle_restore(void)
194 ovs_mutex_lock(&proctitle_mutex);
195 if (saved_proctitle) {
196 memcpy(argv_start, saved_proctitle, argv_size);
197 free(saved_proctitle);
198 saved_proctitle = NULL;
200 ovs_mutex_unlock(&proctitle_mutex);
202 #else /* !LINUX_DATAPATH*/
203 /* Stubs that don't do anything on non-Linux systems. */
206 proctitle_init(int argc OVS_UNUSED, char **argv OVS_UNUSED)
210 #if !(defined(__FreeBSD__) || defined(__NetBSD__))
211 /* On these platforms we #define this to setproctitle. */
213 proctitle_set(const char *format OVS_UNUSED, ...)
219 proctitle_restore(void)
222 #endif /* !LINUX_DATAPATH */