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 #include <common/sessiond-comm/sessiond-comm.h>
  30
  31 static char *opt_session_name;
  32
  33 enum {
  34         OPT_HELP = 1,
  35         OPT_LIST_OPTIONS,
  36 };
  37
  38 static struct poptOption long_options[] = {
  39         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  40         {"help",      'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  41         {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  42         {0, 0, 0, 0, 0, 0, 0}
  43 };
  44
  45 /*
  46  * usage
  47  */
  48 static void usage(FILE *ofp)
  49 {
  50         fprintf(ofp, "usage: lttng start [NAME] [OPTIONS]\n");
  51         fprintf(ofp, "\n");
  52         fprintf(ofp, "Where NAME is an optional session name. If not specified, lttng will\n");
  53         fprintf(ofp, "get it from the configuration directory (.lttng).\n");
  54         fprintf(ofp, "\n");
  55         fprintf(ofp, "Options:\n");
  56         fprintf(ofp, "  -h, --help               Show this help\n");
  57         fprintf(ofp, "      --list-options       Simple listing of options\n");
  58         fprintf(ofp, "\n");
  59 }
  60
  61 /*
  62  *  start_tracing
  63  *
  64  *  Start tracing for all trace of the session.
  65  */
  66 static int start_tracing(void)
  67 {
  68         int ret;
  69         char *session_name;
  70
  71         if (opt_session_name == NULL) {
  72                 session_name = get_session_name();
  73                 if (session_name == NULL) {
  74                         ret = CMD_ERROR;
  75                         goto error;
  76                 }
  77         } else {
  78                 session_name = opt_session_name;
  79         }
  80
  81         DBG("Starting tracing for session %s", session_name);
  82
  83         ret = lttng_start_tracing(session_name);
  84         if (ret < 0) {
  85                 switch (-ret) {
  86                 case LTTNG_ERR_TRACE_ALREADY_STARTED:
  87                         WARN("Tracing already started for session %s", session_name);
  88                         break;
  89                 default:
  90                         ERR("%s", lttng_strerror(ret));
  91                         break;
  92                 }
  93                 goto free_name;
  94         }
  95
  96         ret = CMD_SUCCESS;
  97
  98         MSG("Tracing started for session %s", session_name);
  99
 100 free_name:
 101         if (opt_session_name == NULL) {
 102                 free(session_name);
 103         }
 104 error:
 105         return ret;
 106 }
 107
 108 /*
 109  *  cmd_start
 110  *
 111  *  The 'start <options>' first level command
 112  */
 113 int cmd_start(int argc, const char **argv)
 114 {
 115         int opt, ret = CMD_SUCCESS;
 116         static poptContext pc;
 117
 118         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 119         poptReadDefaultConfig(pc, 0);
 120
 121         while ((opt = poptGetNextOpt(pc)) != -1) {
 122                 switch (opt) {
 123                 case OPT_HELP:
 124                         usage(stdout);
 125                         goto end;
 126                 case OPT_LIST_OPTIONS:
 127                         list_cmd_options(stdout, long_options);
 128                         goto end;
 129                 default:
 130                         usage(stderr);
 131                         ret = CMD_UNDEFINED;
 132                         goto end;
 133                 }
 134         }
 135
 136         opt_session_name = (char*) poptGetArg(pc);
 137
 138         ret = start_tracing();
 139
 140 end:
 141         poptFreeContext(pc);
 142         return ret;
 143 }