From 6d392f1a8958a4d6c2393ce5d494c5a119a1039b Mon Sep 17 00:00:00 2001
From: Alex Karle <alex@alexkarle.com>
Date: Mon, 23 Aug 2021 22:34:23 -0400
Subject: [PATCH] bin: Add t, a small tag-jumping tool for ed(1)

I like to mess around in ed(1) in my free time. I've always thought
adapting to the environment was a fun challenge (although maybe it's
a fools errand). Either way, tag-jumping is incredibly useful for
navigating a new codebase. This new script is a step closer to that!

usage:

	$ e
	... view code
	> !t main
	jumping to main.c, search the following:
	/^main(volatile int argc, char \*\* volatile argv)$/
	> /^main(volatile int argc, char \*\* volatile argv)$/
	main(volatile int argc, char ** volatile argv)
	... view code
	> q
	... back where we started!
---
 bin/t | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)
 create mode 100755 bin/t

diff --git a/bin/t b/bin/t
new file mode 100755
index 0000000..2322781
--- /dev/null
+++ b/bin/t
@@ -0,0 +1,38 @@
+#!/bin/sh
+# t -- tag jumping in ed(1)
+#
+# core concept:
+#    we simulate a "tag stack" by recursing within ed(1). When you're done
+#    at this tag, just `q` out of there!
+#
+#    NOTE: unfortunately, we can't get ed(1) to jump to the location within
+#    the file (without maybe some crazy hacks like using a fifo for stdin..
+#    but even that's likely to fail). The best we can do is output the cmd
+#    to search!
+die() {
+	echo "$*" 1>&2
+	exit 1
+}
+
+[ -z "$1" ] && die "usage: t TAG"
+[ ! -e "tags" ] && die "no ./tags file"
+
+TLINE=$(grep "^$1	" tags | head -n 1)
+[ -z "$TLINE" ] && die "tag not found"
+
+file=$(echo "$TLINE" | cut -f2)
+regex=$(echo "$TLINE" | cut -f3)
+
+# trim the universal ctags regex bits
+# also convert it to a real regex by escaping any special chars!
+regex=$(echo "$regex" | sed \
+    -e 's/;"$//' \
+    -e 's/\\/\\\\/g' \
+    -e 's/\*/\\*/g' \
+    -e 's/\[/\\[/g' \
+    -e 's/\]/\\]/g' \
+    -e 's/\./\\./g')
+
+echo "jumping to $file, search the following:"
+echo "$regex"
+exec e "$file"
--
libgit2 1.1.0