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 };
  35
  36 static struct poptOption long_options[] = {
  37         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  38         {"help",      'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  39         {0, 0, 0, 0, 0, 0, 0}
  40 };
  41
  42 /*
  43  * usage
  44  */
  45 static void usage(FILE *ofp)
  46 {
  47         fprintf(ofp, "usage: lttng start [options] [NAME]\n");
  48         fprintf(ofp, "\n");
  49         fprintf(ofp, "Where NAME is an optional session name. If not specified, lttng will\n");
  50         fprintf(ofp, "get it from the configuration directory (.lttng).\n");
  51         fprintf(ofp, "\n");
  52         fprintf(ofp, "  -h, --help               Show this help\n");
  53         fprintf(ofp, "\n");
  54 }
  55
  56 /*
  57  *  start_tracing
  58  *
  59  *  Start tracing for all trace of the session.
  60  */
  61 static int start_tracing(void)
  62 {
  63         int ret = CMD_SUCCESS;
  64         char *session_name;
  65
  66         if (opt_session_name == NULL) {
  67                 session_name = get_session_name();
  68                 if (session_name == NULL) {
  69                         ret = CMD_ERROR;
  70                         goto error;
  71                 }
  72         } else {
  73                 session_name = opt_session_name;
  74         }
  75
  76         DBG("Starting tracing for session %s", session_name);
  77
  78         ret = lttng_start_tracing(session_name);
  79         if (ret < 0) {
  80                 goto free_name;
  81         }
  82
  83         MSG("Tracing started for session %s", session_name);
  84
  85 free_name:
  86         if (opt_session_name == NULL) {
  87                 free(session_name);
  88         }
  89 error:
  90         return ret;
  91 }
  92
  93 /*
  94  *  cmd_start
  95  *
  96  *  The 'start <options>' first level command
  97  */
  98 int cmd_start(int argc, const char **argv)
  99 {
 100         int opt, ret;
 101         static poptContext pc;
 102
 103         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 104         poptReadDefaultConfig(pc, 0);
 105
 106         while ((opt = poptGetNextOpt(pc)) != -1) {
 107                 switch (opt) {
 108                 case OPT_HELP:
 109                         usage(stderr);
 110                         ret = CMD_SUCCESS;
 111                         goto end;
 112                 default:
 113                         usage(stderr);
 114                         ret = CMD_UNDEFINED;
 115                         goto end;
 116                 }
 117         }
 118
 119         opt_session_name = (char*) poptGetArg(pc);
 120
 121         ret = start_tracing();
 122
 123 end:
 124         return ret;
 125 }