/*
- * Copyright (c) 2008 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010 Nicira Networks.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include "command-line.h"
#include <getopt.h>
#include <limits.h>
+#include <stdlib.h>
#include "util.h"
-#include "vlog.h"
/* Given the GNU-style long options in 'options', returns a string that may be
* passed to getopt() with the corresponding short options. The caller is
return xstrdup(short_options);
}
+/* Runs the command designated by argv[0] within the command table specified by
+ * 'commands', which must be terminated by a command whose 'name' member is a
+ * null pointer.
+ *
+ * Command-line options should be stripped off, so that a typical invocation
+ * looks like "run_command(argc - optind, argv + optind, my_commands);". */
+void
+run_command(int argc, char *argv[], const struct command commands[])
+{
+ const struct command *p;
+
+ if (argc < 1) {
+ ovs_fatal(0, "missing command name; use --help for help");
+ }
+
+ for (p = commands; p->name != NULL; p++) {
+ if (!strcmp(p->name, argv[0])) {
+ int n_arg = argc - 1;
+ if (n_arg < p->min_args) {
+ ovs_fatal(0, "'%s' command requires at least %d arguments",
+ p->name, p->min_args);
+ } else if (n_arg > p->max_args) {
+ ovs_fatal(0, "'%s' command takes at most %d arguments",
+ p->name, p->max_args);
+ } else {
+ p->handler(argc, argv);
+ if (ferror(stdout)) {
+ ovs_fatal(0, "write to stdout failed");
+ }
+ if (ferror(stderr)) {
+ ovs_fatal(0, "write to stderr failed");
+ }
+ return;
+ }
+ }
+ }
+
+ ovs_fatal(0, "unknown command '%s'; use --help for help", argv[0]);
+}
+\f
+/* Process title. */
+
+#ifdef __linux__
+static char *argv_start; /* Start of command-line arguments in memory. */
+static size_t argv_size; /* Number of bytes of command-line arguments. */
+static char *saved_proctitle; /* Saved command-line arguments. */
+
+/* Prepares the process so that proctitle_set() can later succeed.
+ *
+ * This modifies the argv[] array so that it no longer points into the memory
+ * that it originally does. Later, proctitle_set() might overwrite that
+ * memory. That means that this function should be called before anything else
+ * that accesses the process's argv[] array. Ideally, it should be called
+ * before anything else, period, at the very beginning of program
+ * execution. */
+void
+proctitle_init(int argc, char **argv)
+{
+ int i;
+
+ if (!argc || !argv[0]) {
+ /* This situation should never occur, but... */
+ return;
+ }
+
+ /* Specialized version of first loop iteration below. */
+ argv_start = argv[0];
+ argv_size = strlen(argv[0]) + 1;
+ argv[0] = xstrdup(argv[0]);
+
+ for (i = 1; i < argc; i++) {
+ size_t size = strlen(argv[i]) + 1;
+
+ /* Add (argv[i], strlen(argv[i])+1) to (argv_start, argv_size). */
+ if (argv[i] + size == argv_start) {
+ /* Arguments grow downward in memory. */
+ argv_start -= size;
+ argv_size += size;
+ } else if (argv[i] == argv_start + argv_size) {
+ /* Arguments grow upward in memory. */
+ argv_size += size;
+ } else {
+ /* Arguments not contiguous. (Is this really Linux?) */
+ }
+
+ /* Copy out the old argument so we can reuse the space. */
+ argv[i] = xstrdup(argv[i]);
+ }
+}
+
+/* Changes the name of the process, as shown by "ps", to 'format', which is
+ * formatted as if by printf(). */
+void
+proctitle_set(const char *format, ...)
+{
+ va_list args;
+ int n;
+
+ if (!argv_start || argv_size < 8) {
+ return;
+ }
+
+ if (!saved_proctitle) {
+ saved_proctitle = xmemdup(argv_start, argv_size);
+ }
+
+ va_start(args, format);
+ n = vsnprintf(argv_start, argv_size, format, args);
+ if (n >= argv_size) {
+ /* The name is too long, so add an ellipsis at the end. */
+ strcpy(&argv_start[argv_size - 4], "...");
+ } else {
+ /* Fill the extra space with null bytes, so that trailing bytes don't
+ * show up in the command line. */
+ memset(&argv_start[n], '\0', argv_size - n);
+ }
+ va_end(args);
+}
+
+/* Restores the process's original command line, as seen by "ps". */
+void
+proctitle_restore(void)
+{
+ if (saved_proctitle) {
+ memcpy(argv_start, saved_proctitle, argv_size);
+ free(saved_proctitle);
+ saved_proctitle = NULL;
+ }
+}
+#else /* !__linux__ */
+/* Stubs that don't do anything on non-Linux systems. */
+
+void
+proctitle_init(int argc OVS_UNUSED, char **argv OVS_UNUSED)
+{
+}
+
+void
+proctitle_set(const char *format OVS_UNUSED, ...)
+{
+}
+
+void
+proctitle_restore(void)
+{
+}
+#endif /* !__linux__ */
projects / cascardo / ovs.git / blobdiff