Question

Given the hash of a blob, is there a way to get a list of commits that have this blob in their tree?

Answer 1

Both of the following scripts take the blob’s SHA1 as the first argument, and after it, optionally, any arguments that git log will understand. E.g. --all to search in all branches instead of just the current one, or -g to search in the reflog, or whatever else you fancy.

Here it is as a shell script – short and sweet, but slow:

#!/bin/sh obj_name="$1" shift git log "$@" --pretty=tformat:'%T %h %s' \ | while read tree commit subject ; do     if git ls-tree -r $tree | grep -q "$obj_name" ; then         echo $commit "$subject"     fi done 

And an optimised version in Perl, still quite short but much faster:

#!/usr/bin/perl use 5.008; use strict; use Memoize;  my $obj_name;  sub check_tree {     my ( $tree ) = @_;     my @subtree;      {         open my $ls_tree, '-|', git => 'ls-tree' => $tree             or die "Couldn't open pipe to git-ls-tree: $!\n";          while ( <$ls_tree> ) {             /\A[0-7]{6} (\S+) (\S+)/                 or die "unexpected git-ls-tree output";             return 1 if $2 eq $obj_name;             push @subtree, $2 if $1 eq 'tree';         }     }      check_tree( $_ ) && return 1 for @subtree;      return; }  memoize 'check_tree';  die "usage: git-find-blob <blob> [<git-log arguments ...>]\n"     if not @ARGV;  my $obj_short = shift @ARGV; $obj_name = do {     local $ENV{'OBJ_NAME'} = $obj_short;      `git rev-parse --verify \$OBJ_NAME`; } or die "Couldn't parse $obj_short: $!\n"; chomp $obj_name;  open my $log, '-|', git => log => @ARGV, '--pretty=format:%T %h %s'     or die "Couldn't open pipe to git-log: $!\n";  while ( <$log> ) {     chomp;     my ( $tree, $commit, $subject ) = split " ", $_, 3;     print "$commit $subject\n" if check_tree( $tree ); }