src/bin/lttng/commands/start.c

   1 /*
   2  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; only version 2
   7  * of the License.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  17  */
  18
  19 #define _GNU_SOURCE
  20 #include <popt.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <sys/stat.h>
  25 #include <sys/types.h>
  26 #include <unistd.h>
  27
  28 #include "../command.h"
  29
  30 static char *opt_session_name;
  31
  32 enum {
  33         OPT_HELP = 1,
  34         OPT_LIST_OPTIONS,
  35 };
  36
  37 static struct poptOption long_options[] = {
  38         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  39         {"help",      'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  40         {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  41         {0, 0, 0, 0, 0, 0, 0}
  42 };
  43
  44 /*
  45  * usage
  46  */
  47 static void usage(FILE *ofp)
  48 {
  49         fprintf(ofp, "usage: lttng start [options] [NAME]\n");
  50         fprintf(ofp, "\n");
  51         fprintf(ofp, "Where NAME is an optional session name. If not specified, lttng will\n");
  52         fprintf(ofp, "get it from the configuration directory (.lttng).\n");
  53         fprintf(ofp, "\n");
  54         fprintf(ofp, "  -h, --help               Show this help\n");
  55         fprintf(ofp, "      --list-options       Simple listing of options\n");
  56         fprintf(ofp, "\n");
  57 }
  58
  59 /*
  60  *  start_tracing
  61  *
  62  *  Start tracing for all trace of the session.
  63  */
  64 static int start_tracing(void)
  65 {
  66         int ret;
  67         char *session_name;
  68
  69         if (opt_session_name == NULL) {
  70                 session_name = get_session_name();
  71                 if (session_name == NULL) {
  72                         ret = CMD_ERROR;
  73                         goto error;
  74                 }
  75         } else {
  76                 session_name = opt_session_name;
  77         }
  78
  79         DBG("Starting tracing for session %s", session_name);
  80
  81         ret = lttng_start_tracing(session_name);
  82         if (ret < 0) {
  83                 /* Don't set ret so lttng can interpret the sessiond error. */
  84                 goto free_name;
  85         }
  86
  87         ret = CMD_SUCCESS;
  88
  89         MSG("Tracing started for session %s", session_name);
  90
  91 free_name:
  92         if (opt_session_name == NULL) {
  93                 free(session_name);
  94         }
  95 error:
  96         return ret;
  97 }
  98
  99 /*
 100  *  cmd_start
 101  *
 102  *  The 'start <options>' first level command
 103  */
 104 int cmd_start(int argc, const char **argv)
 105 {
 106         int opt, ret = CMD_SUCCESS;
 107         static poptContext pc;
 108
 109         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 110         poptReadDefaultConfig(pc, 0);
 111
 112         while ((opt = poptGetNextOpt(pc)) != -1) {
 113                 switch (opt) {
 114                 case OPT_HELP:
 115                         usage(stdout);
 116                         goto end;
 117                 case OPT_LIST_OPTIONS:
 118                         list_cmd_options(stdout, long_options);
 119                         goto end;
 120                 default:
 121                         usage(stderr);
 122                         ret = CMD_UNDEFINED;
 123                         goto end;
 124                 }
 125         }
 126
 127         opt_session_name = (char*) poptGetArg(pc);
 128
 129         ret = start_tracing();
 130
 131 end:
 132         poptFreeContext(pc);
 133         return ret;
 134 }