Change get cmdline function and list print

Make the function return a pointer to the proc cmdline allocated string.
List traces and applications are modified to use it.

Signed-off-by: David Goulet <david.goulet@polymtl.ca>

diff --git a/lttng/lttng.c b/lttng/lttng.c
index 16487ff74a99cb2149bda0964af415ee2721868d..e286917ed1effff58afaacb91c1f8bcb780d7de4 100644 (file)
--- a/lttng/lttng.c
+++ b/lttng/lttng.c
@@ -46,8 +46,8 @@ static int process_opt_list_traces(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);
 static int validate_options(void);
+static char *get_cmdline_by_pid(pid_t pid);
 
 /*
  *  start_client
@@ -153,7 +153,9 @@ static int process_opt_list_traces(void)
        MSG("Userspace traces:");
        for (i = 0; i < ret; i++) {
                if (traces[i].type == USERSPACE) {
-                       MSG("\t%d) %s (pid: %d)", i, traces[i].name, traces[i].pid);
+                       MSG("\t%d) %s (pid: %d): %s",
+                                       i, traces[i].name, traces[i].pid,
+                                       get_cmdline_by_pid(traces[i].pid));
                } else {
                        break;
                }
@@ -249,8 +251,8 @@ static int process_opt_list_apps(void)
 
        MSG("LTTng UST traceable application [name (pid)]:");
        for (i=0; i < count; i++) {
-               ret = get_cmdline_by_pid(pids[i], &cmdline);
-               if (!ret) {
+               cmdline = get_cmdline_by_pid(pids[i]);
+               if (cmdline == NULL) {
                        MSG("\t(not running) (%d)", pids[i]);
                        continue;
                }
@@ -270,34 +272,32 @@ error:
 /*
  *  get_cmdline_by_pid
  *
- *  Get command line from /proc for a
- *  specific pid. Allocate cmdline so the
- *  user must free() that pointer.
+ *  Get command line from /proc for a specific pid.
  *
- *  On success, return 1
- *  On error (not found), return 0
+ *  On success, return an allocated string pointer pointing to
+ *  the proc cmdline.
+ *  On error, return NULL.
  */
-static int get_cmdline_by_pid(pid_t pid, char **cmdline)
+static char *get_cmdline_by_pid(pid_t pid)
 {
        int ret;
        FILE *fp;
+       char *cmdline = NULL;
        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;
+               goto end;
        }
 
        /* Caller must free() *cmdline */
-       *cmdline = malloc(PATH_MAX);
-       ret = fread(*cmdline, 1, PATH_MAX, fp);
+       cmdline = malloc(PATH_MAX);
+       ret = fread(cmdline, 1, PATH_MAX, fp);
        fclose(fp);
 
-       return 1;
-
-not_running:
-       return 0;
+end:
+       return cmdline;
 }
 
 /*