kernelshark: Manually look for trace-cmd in PATH

When executing a record, walk the PATH variable to search for
trace-cmd. If it is not found we can nicely give a warning instead
of trying to execute it.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 57 insertions, 1 deletions

diff --git a/trace-capture.c b/trace-capture.c
index b5e8852..27ae757 100644
--- a/trace-capture.c
+++ b/trace-capture.c
@@ -274,6 +274,51 @@ static int calculate_trace_cmd_words(struct trace_capture *cap)
         return words;
 }
 
+static char *find_tracecmd(void)
+{
+        struct stat st;
+        char *path = getenv("PATH");
+        char *saveptr;
+        char *str;
+        char *loc;
+        char *tracecmd = NULL;
+        int len;
+        int ret;
+
+        if (!path)
+                return NULL;
+
+        path = strdup(path);
+
+        for (str = path; ; str = NULL) {
+                loc = strtok_r(str, ":", &saveptr);
+                if (!loc)
+                        break;
+                len = strlen(loc) + 11;
+                tracecmd = malloc_or_die(len);
+                snprintf(tracecmd, len, "%s/trace-cmd", loc);
+                ret = stat(tracecmd, &st);
+
+                if (ret >= 0 && S_ISREG(st.st_mode)) {
+                        /* Do we have execute permissions */
+                        if (st.st_uid == geteuid() &&
+                            st.st_mode & S_IXUSR)
+                                break;
+                        if (st.st_gid == getegid() &&
+                            st.st_mode & S_IXGRP)
+                                break;
+                        if (st.st_mode & S_IXOTH)
+                                break;
+                }
+
+                free(tracecmd);
+                tracecmd = NULL;
+        }
+        free(path);
+
+        return tracecmd;
+}
+
 static int add_trace_cmd_words(struct trace_capture *cap, char **args)
 {
         struct event_format *event;
@@ -286,7 +331,10 @@ static int add_trace_cmd_words(struct trace_capture *cap, char **args)
 
         output = gtk_entry_get_text(GTK_ENTRY(cap->file_entry));
 
-        args[words++] = strdup("trace-cmd");
+        args[words++] = find_tracecmd();
+        if (!args[0])
+                return -1;
+
         args[words++] = strdup("record");
         args[words++] = strdup("-o");
         args[words++] = strdup(output);
@@ -706,6 +754,14 @@ static void execute_button_clicked(GtkWidget *widget, gpointer data)
         GtkWidget *dialog;
         GtkWidget *label;
         const char *filename;
+        char *tracecmd;
+
+        tracecmd = find_tracecmd();
+        if (!tracecmd) {
+                warning("trace-cmd not found in path");
+                return;
+        }
+        free(tracecmd);
 
         filename = gtk_entry_get_text(GTK_ENTRY(cap->file_entry));