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 modify
   5  * it under the terms of the GNU General Public License, version 2 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _GNU_SOURCE
  19 #include <popt.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <sys/stat.h>
  24 #include <sys/types.h>
  25 #include <unistd.h>
  26
  27 #include "../command.h"
  28
  29 static char *opt_session_name;
  30
  31 enum {
  32         OPT_HELP = 1,
  33         OPT_LIST_OPTIONS,
  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         {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  40         {0, 0, 0, 0, 0, 0, 0}
  41 };
  42
  43 /*
  44  * usage
  45  */
  46 static void usage(FILE *ofp)
  47 {
  48         fprintf(ofp, "usage: lttng start [options] [NAME]\n");
  49         fprintf(ofp, "\n");
  50         fprintf(ofp, "Where NAME is an optional session name. If not specified, lttng will\n");
  51         fprintf(ofp, "get it from the configuration directory (.lttng).\n");
  52         fprintf(ofp, "\n");
  53         fprintf(ofp, "  -h, --help               Show this help\n");
  54         fprintf(ofp, "      --list-options       Simple listing of options\n");
  55         fprintf(ofp, "\n");
  56 }
  57
  58 /*
  59  *  start_tracing
  60  *
  61  *  Start tracing for all trace of the session.
  62  */
  63 static int start_tracing(void)
  64 {
  65         int ret;
  66         char *session_name;
  67
  68         if (opt_session_name == NULL) {
  69                 session_name = get_session_name();
  70                 if (session_name == NULL) {
  71                         ret = CMD_ERROR;
  72                         goto error;
  73                 }
  74         } else {
  75                 session_name = opt_session_name;
  76         }
  77
  78         DBG("Starting tracing for session %s", session_name);
  79
  80         ret = lttng_start_tracing(session_name);
  81         if (ret < 0) {
  82                 /* Don't set ret so lttng can interpret the sessiond error. */
  83                 goto free_name;
  84         }
  85
  86         ret = CMD_SUCCESS;
  87
  88         MSG("Tracing started for session %s", session_name);
  89
  90 free_name:
  91         if (opt_session_name == NULL) {
  92                 free(session_name);
  93         }
  94 error:
  95         return ret;
  96 }
  97
  98 /*
  99  *  cmd_start
 100  *
 101  *  The 'start <options>' first level command
 102  */
 103 int cmd_start(int argc, const char **argv)
 104 {
 105         int opt, ret = CMD_SUCCESS;
 106         static poptContext pc;
 107
 108         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 109         poptReadDefaultConfig(pc, 0);
 110
 111         while ((opt = poptGetNextOpt(pc)) != -1) {
 112                 switch (opt) {
 113                 case OPT_HELP:
 114                         usage(stdout);
 115                         goto end;
 116                 case OPT_LIST_OPTIONS:
 117                         list_cmd_options(stdout, long_options);
 118                         goto end;
 119                 default:
 120                         usage(stderr);
 121                         ret = CMD_UNDEFINED;
 122                         goto end;
 123                 }
 124         }
 125
 126         opt_session_name = (char*) poptGetArg(pc);
 127
 128         ret = start_tracing();
 129
 130 end:
 131         poptFreeContext(pc);
 132         return ret;
 133 }