libcgroup: Add command line options to set log level and log destinations.

From: Jan Safranek <jsafrane@redhat.com>

I rewrote the parsing to getopt - it's IMHO less error-prone and
new options can be added quite easily. Each new option has short
and long variant, both shown in --help.

Signed-off-by: Jan Safranek <jsafrane@redhat.com>
Acked-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
git-svn-id: https://libcg.svn.sourceforge.net/svnroot/libcg/trunk@321 4f4bb910-9a46-0410-90c8-c897d4f1cd53

diff --git a/cgrulesengd.c b/cgrulesengd.c
index 20d710d29391aabe9e1e748dbd0a539633084dc5..3a304762e807291eb4e5146976e339b11d9bf092 100644 (file)
--- a/cgrulesengd.c
+++ b/cgrulesengd.c
@@ -45,6 +45,7 @@
 #include <signal.h>
 #include <time.h>
 #include <syslog.h>
+#include <getopt.h>
 
 #include <sys/stat.h>
 #include <unistd.h>
@@ -78,9 +79,18 @@ void usage(FILE* fd, const char* msg, ...)
        if (msg)
                vfprintf(fd, msg, ap);
        fprintf(fd, "\n");
-       fprintf(fd, "cgrulesengd -- a daemon for the cgroups rules engine\n");
-       fprintf(fd, "  usage : cgrulesengd [--nodaemon] [--nolog] [--log FILE]"
-                       "\n");
+       fprintf(fd, "cgrulesengd -- a daemon for the cgroups rules engine\n\n");
+       fprintf(fd, "Usage : cgrulesengd [options]\n\n");
+       fprintf(fd, "  options :\n");
+       fprintf(fd, "    -q           | --quiet             quiet mode\n"
+               "    -v           | --verbose           verbose mode\n"
+               "    -f <path>    | --logfile=<path>    write log to file\n"
+               "    -s[facility] | --syslog=[facility] write log to syslog\n"
+               "    -n           | --nodaemom          don't fork daemon\n"
+               "    -d           | --debug             same as -v -v -n -f -\n"
+               "    -Q           | --nolog             disable logging\n"
+               "    -h           | --help              show this help\n\n"
+               );
        va_end(ap);
 }
 
@@ -576,10 +586,53 @@ void cgre_catch_term(int signum)
        exit(EXIT_SUCCESS);
 }
 
+/**
+ * Parse the syslog facility as received on command line.
+ *     @param arg Command line argument with the syslog facility
+ *     @return the syslog facility (e.g. LOG_DAEMON) or 0 on error
+ */
+static int cgre_parse_syslog_facility(const char *arg)
+{
+    if (arg == NULL)
+       return 0;
+
+    if (strlen(arg) > 1)
+       return 0;
+
+       switch (arg[0]) {
+       case '0':
+               return LOG_LOCAL0;
+       case '1':
+               return LOG_LOCAL1;
+       case '2':
+               return LOG_LOCAL2;
+       case '3':
+               return LOG_LOCAL3;
+       case '4':
+               return LOG_LOCAL4;
+       case '5':
+               return LOG_LOCAL5;
+       case '6':
+               return LOG_LOCAL6;
+       case '7':
+               return LOG_LOCAL7;
+       case 'D':
+               return LOG_DAEMON;
+       default:
+               return 0;
+       }
+}
+
 int main(int argc, char *argv[])
 {
        /* Patch to the log file */
-       char logp[FILENAME_MAX];
+       const char *logp = NULL;
+
+       /* Syslog facility */
+       int facility = 0;
+
+       /* Verbose level */
+       int verbosity = 2;
 
        /* For catching signals */
        struct sigaction sa;
@@ -587,14 +640,22 @@ int main(int argc, char *argv[])
        /* Should we daemonize? */
        unsigned char daemon = 1;
 
-       /* Log level */
-       int loglevel = 4;
-
        /* Return codes */
        int ret = 0;
 
-       /* Loop variable */
-       int i = 0;
+       /* Command line arguments */
+       const char *short_options = "hvqf:s::ndQ";
+       struct option long_options[] = {
+               {"help", no_argument, NULL, 'h'},
+               {"verbose", no_argument, NULL, 'v'},
+               {"quiet", no_argument, NULL, 'q'},
+               {"logfile", required_argument, NULL, 'f'},
+               {"syslog", optional_argument, NULL, 's'},
+               {"nodaemon", no_argument, NULL, 'n'},
+               {"debug", no_argument, NULL, 'd'},
+               {"nolog", no_argument, NULL, 'Q'},
+               {NULL, 0, NULL, 0}
+       };
 
        /* Make sure the user is root. */
        if (getuid() != 0) {
@@ -604,33 +665,66 @@ int main(int argc, char *argv[])
                goto finished;
        }
 
-       /* Set the default log file. */
-       memset(logp, '\0', FILENAME_MAX);
-       strncpy(logp, "/root/cgrulesengd.log",
-                       strlen("/root/cgrulesengd.log"));
-       logfile = NULL;
-
-       /* Parse user args. */
-       for (i = 1; i < argc; i++) {
-               if (strncmp(argv[i], "--log", strlen("--log")) == 0) {
-                       i++;
-                       memset(logp, '\0', FILENAME_MAX);
-                       strncpy(logp, argv[i], strlen(argv[i]));
-                       continue;
-               }
-               if (strncmp(argv[i], "--nodaemon", strlen("--nodaemon")) == 0) {
+       while (1) {
+               int c;
+
+               c = getopt_long(argc, argv, short_options, long_options, NULL);
+               if (c == -1)
+                       break;
+
+               switch (c) {
+               case 'h':   /* --help */
+                       usage(stdout, "Help:\n");
+                       ret = 0;
+                       goto finished;
+
+               case 'v':   /* --verbose */
+                       verbosity++;
+                       break;
+
+               case 'q':   /* --quiet */
+                       verbosity--;
+                       break;
+
+               case 'Q':   /* --nolog */
+                       verbosity = 0;
+                       break;
+
+               case 'f':   /* --logfile=<filename> */
+                       logp = optarg;
+                       break;
+
+               case 's':   /* --syslog=[facility] */
+                       if (optarg) {
+                               facility = cgre_parse_syslog_facility(optarg);
+                               if (facility == 0) {
+                                       fprintf(stderr,
+                                               "Unknown syslog facility: %s\n",
+                                               optarg);
+                                       ret = 2;
+                                       goto finished;
+                               }
+                       } else {
+                               facility = LOG_DAEMON;
+                       }
+                       break;
+
+               case 'n':   /* --no-fork */
                        daemon = 0;
-                       continue;
-               }
-               if (strncmp(argv[i], "--nolog", strlen("--nolog")) == 0) {
-                       loglevel = 0;
-                       continue;
-               }
+                       break;
 
-               /* If we get here, the user specified an invalid arg. */
-               usage(stderr, "Invalid argument: %s", argv[i]);
-               ret = 2;
-               goto finished;
+               case 'd':   /* --debug */
+                       /* same as -vvn */
+                       daemon = 0;
+                       verbosity = 4;
+                       logp = "-";
+                       break;
+
+               default:
+                       usage(stderr, "");
+                       ret = 2;
+                       goto finished;
+               }
        }
 
        /* Initialize libcgroup. */
@@ -648,7 +742,7 @@ int main(int argc, char *argv[])
        }
 
        /* Now, start the daemon. */
-       ret = cgre_start_daemon(logp, 0, daemon, loglevel);
+       ret = cgre_start_daemon(logp, facility, daemon, verbosity);
        if (ret < 0) {
                fprintf(stderr, "Error: Failed to launch the daemon, %d\n",
                        ret);