diff-grep
diff-grep is a tool for filtering diffs to only include the hunks matching the given patterns.
Usage
Produce a diff, for example using git diff:
$ git diff ... > /tmp/original.diff
$ cat /tmp/original.diff
diff --git c/docs/ld.1.html w/docs/ld.1.html
index 2ac7626c..eeb7bdc5 100644
--- c/docs/ld.1.html
+++ w/docs/ld.1.html
@@ -897,7 +903,16 @@ When linking for two-level namespace, <code class="Nm">ld</code> does not verify
build time. This option relaxes that requirement, allowing you to mix
object files compiled for different ARM subtypes.</dd>
<dt><a class="permalink" href="#no_uuid"><code class="Fl" id="no_uuid">-no_uuid</code></a></dt>
- <dd>Do not generate an LC_UUID load command in the output file.</dd>
+ <dd>Do not generate an LC_UUID load command in the output file. Be warned that
+ binaries without UUIDs may cause the debugger and crash reporting tools to
+ be unable to track and inspect the binary.</dd>
+ <dt><a class="permalink" href="#random_uuid"><code class="Fl" id="random_uuid">-random_uuid</code></a></dt>
+ <dd>Generate a random LC_UUID load command in the output file. By default the
+ linker generates the UUID of the output file based on a hash of the output
+ file's content. But for very large output files, the hash can slow down
+ the link. Using a hash based UUID is important for reproducible builds,
+ but if you are just doing rapid debug builds, using -random_uuid may
+ improve turn around time.</dd>
<dt><a class="permalink" href="#root_safe"><code class="Fl" id="root_safe">-root_safe</code></a></dt>
<dd>Sets the MH_ROOT_SAFE bit in the mach header of the output file.</dd>
<dt><a class="permalink" href="#setuid_safe"><code class="Fl" id="setuid_safe">-setuid_safe</code></a></dt>
@@ -1315,7 +1330,7 @@ as(1), ar(1), cc(1), nm(1), otool(1) lipo(1), arch(3), dyld(3), Mach-O(5),
</div>
<table class="foot">
<tr>
- <td class="foot-date">March 7, 2018</td>
+ <td class="foot-date">August 7, 2020</td>
<td class="foot-os">Darwin</td>
</tr>
</table>
Filter the diff where every modified line in a hunk must match the given pattern(s):
$ cat /tmp/original.diff | diff-grep foot-date --output /tmp/filtered.diff
$ cat /tmp/filtered.diff
--- c/docs/ld.1.html
+++ w/docs/ld.1.html
@@ -1315,7 +1330,7 @@ as(1), ar(1), cc(1), nm(1), otool(1) lipo(1), arch(3), dyld(3), Mach-O(5),
</div>
<table class="foot">
<tr>
- <td class="foot-date">March 7, 2018</td>
+ <td class="foot-date">August 7, 2020</td>
<td class="foot-os">Darwin</td>
</tr>
</table>
Use the filtered diff somewhere:
$ git apply --reverse /tmp/filtered.diff
In this example, we revert only the matching hunk using git apply --reverse. This can be useful when you want to stage, or checkout, large mechanical diffs that you have intertwined other changes with.
Installation
brew install keith/formulae/diff-grep
Manually, after installing rust:
cargo install --locked --path .
