From ecc931ce2e7f22c83abfd6bd2de47b1ba5457382 Mon Sep 17 00:00:00 2001
From: Jose Fernandez <josef@netflix.com>
Date: Fri, 20 Aug 2021 17:44:58 -0700
Subject: [PATCH] Update stackcollapse-bpftrace to work with book examples

---
 stackcollapse-bpftrace.pl | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/stackcollapse-bpftrace.pl b/stackcollapse-bpftrace.pl
index e5d32a57..f458c3e3 100755
--- a/stackcollapse-bpftrace.pl
+++ b/stackcollapse-bpftrace.pl
@@ -51,15 +51,21 @@
 foreach (<>) {
   chomp;
   if (!$in_stack) {
-    if (/^@\[/) {
+    if (/^@\[$/) {
       $in_stack = 1;
+    } elsif (/^@\[,\s(.*)\]: (\d+)/) {
+      print $1 . " $2\n";
     }
   } else {
-    if (m/^\]: (\d+)/) {
-      print join(';', reverse(@stack)) . " $1\n";
+    if (m/^,?\s?(.*)\]: (\d+)/) {
+      if (length $1) {
+        push(@stack, $1);
+      }
+      print join(';', reverse(@stack)) . " $2\n";
       $in_stack = 0;
       @stack = ();
     } else {
+      $_ =~ s/^\s+//;
       push(@stack, $_);
     }
   }