Improve collect error messages (#4)

Author: simonchatts

collect

@@ -207,6 +207,16 @@ perf_version=$(perf --version)
 process_opts "$@"
 find_compressor
 
+# Check if running as root
+if [ "$(id -u)" -ne 0 ]; then
+    die "This script must be run as root."
+fi
+
+# Check if perf is available
+if ! which perf >/dev/null 2>&1; then
+    die "The 'perf' command is not found in PATH."
+fi
+
 # Specific to Cisco IOS-XR: disable memdbg if present, since otherwise it can
 # cause perf to coredump.
 if [ "$LD_PRELOAD" = "/pkg/lib/libmemdbg.so" ]; then