Add the get command line path from PID fct

[lttng-tools.git] / lttng / lttng.c

diff --git a/lttng/lttng.c b/lttng/lttng.c
index 169e70eb0ddeedf5d29ffbe57ffb4f8581b3990f..52c3e3873d27ce967f6cb3294126b64d269144b8 100644 (file)
--- a/lttng/lttng.c
+++ b/lttng/lttng.c
@@ -45,6 +45,7 @@ static int process_opt_list_sessions(void);
 static int process_opt_create_session(void);
 static void sighandler(int sig);
 static int set_signal_handler(void);
+static int get_cmdline_by_pid(pid_t pid, char **cmdline);
 
 /*
  *  start_client
@@ -93,6 +94,19 @@ static int process_client_opt(void)
                }
        }
 
+       if (opt_session_uuid != NULL) {
+               lttng_set_current_session_uuid(opt_session_uuid);
+       }
+
+       if (opt_create_trace) {
+               DBG("Create trace for pid %d", opt_create_trace);
+               ret = lttng_ust_create_trace(opt_create_trace);
+               if (ret < 0) {
+                       goto end;
+               }
+               MSG("Trace created successfully!\nUse --start PID to start tracing");
+       }
+
        return 0;
 
 end:
@@ -167,9 +181,7 @@ static int process_opt_list_apps(void)
 {
        int i, ret, count;
        pid_t *pids;
-       FILE *fp;
-       char path[24];  /* Can't go bigger than /proc/65535/cmdline */
-       char cmdline[PATH_MAX];
+       char *cmdline;
 
        count = lttng_ust_list_apps(&pids);
        if (count < 0) {
@@ -179,15 +191,13 @@ static int process_opt_list_apps(void)
 
        MSG("LTTng UST traceable application [name (pid)]:");
        for (i=0; i < count; i++) {
-               snprintf(path, sizeof(path), "/proc/%d/cmdline", pids[i]);
-               fp = fopen(path, "r");
-               if (fp == NULL) {
+               ret = get_cmdline_by_pid(pids[i], &cmdline);
+               if (!ret) {
                        MSG("\t(not running) (%d)", pids[i]);
                        continue;
                }
-               ret = fread(cmdline, 1, sizeof(cmdline), fp);
                MSG("\t%s (%d)", cmdline, pids[i]);
-               fclose(fp);
+               free(cmdline);
        }
 
        /* Allocated by lttng_ust_list_apps() */
@@ -199,6 +209,39 @@ error:
        return ret;
 }
 
+/*
+ *  get_cmdline_by_pid
+ *
+ *  Get command line from /proc for a
+ *  specific pid. Allocate cmdline so the
+ *  user must free() that pointer.
+ *
+ *  On success, return 1
+ *  On error (not found), return 0
+ */
+static int get_cmdline_by_pid(pid_t pid, char **cmdline)
+{
+       int ret;
+       FILE *fp;
+       char path[24];  /* Can't go bigger than /proc/65535/cmdline */
+
+       snprintf(path, sizeof(path), "/proc/%d/cmdline", pid);
+       fp = fopen(path, "r");
+       if (fp == NULL) {
+               goto not_running;
+       }
+
+       /* Caller must free() *cmdline */
+       *cmdline = malloc(PATH_MAX);
+       ret = fread(*cmdline, 1, PATH_MAX, fp);
+       fclose(fp);
+
+       return 1;
+
+not_running:
+       return 0;
+}
+
 /*
  *  spawn_sessiond
  *
@@ -353,6 +396,9 @@ static void sighandler(int sig)
 void clean_exit(int code)
 {
        DBG("Clean exit");
+       if (lttng_disconnect_sessiond() < 0) {
+               ERR("Session daemon disconnect failed.");
+       }
        exit(code);
 }
 
@@ -372,12 +418,12 @@ int main(int argc, char *argv[])
 
        ret = parse_args(argc, (const char **) argv);
        if (ret < 0) {
-               return EXIT_FAILURE;
+               clean_exit(EXIT_FAILURE);
        }
 
        ret = set_signal_handler();
        if (ret < 0) {
-               return ret;
+               clean_exit(ret);
        }
 
        if (opt_tracing_group != NULL) {
@@ -390,7 +436,7 @@ int main(int argc, char *argv[])
                DBG("Kernel tracing activated");
                if (getuid() != 0) {
                        ERR("%s must be setuid root", progname);
-                       return -EPERM;
+                       clean_exit(-EPERM);
                }
        }
 
@@ -398,13 +444,15 @@ int main(int argc, char *argv[])
         * If no, a daemon will be spawned.
         */
        if (opt_no_sessiond == 0 && (check_ltt_sessiond() < 0)) {
-               return EXIT_FAILURE;
+               clean_exit(EXIT_FAILURE);
        }
 
        ret = process_client_opt();
        if (ret < 0) {
-               return ret;
+               clean_exit(ret);
        }
 
+       clean_exit(0);
+
        return 0;
 }