Prevent pushes to git containing tabs in certain files (e.g. *.cpp, *.h, CMakeLists.txt)

Question

I\'d like my remote repository to refuse any pushes that contains a file that contains a tab, but only if the file belongs in a certain class (based on the filename). Is that po

Answer 1

Based on benprew's work, here's a pre-script hook that displays an error if any tab characters have been added, as well as the relevant line number. Save the following to .git/hooks/pre-commit.

(Note: pre-commit is the filename. There shouldn't be any . extension)

#!/bin/sh

if git rev-parse --verify HEAD 2>/dev/null
then
  git diff-index -p -M --cached HEAD
else
    :
fi |
perl -e '
    my $found_bad = 0;
    my $filename;
    my $reported_filename = "";
    my $lineno;
    sub bad_line {
        my ($why, $line) = @_;
        if (!$found_bad) {
            print STDERR "*\n";
            print STDERR "* You have some suspicious patch lines:\n";
            print STDERR "*\n";
            $found_bad = 1;
        }
        if ($reported_filename ne $filename) {
            print STDERR "* In $filename\n";
            $reported_filename = $filename;
        }
        print STDERR "* $why (line $lineno)\n";
        print STDERR "$filename:$lineno:$line\n";
    }
    while (<>) {
        if (m|^diff --git a/(.*) b/\1$|) {
            $filename = $1;
            next;
        }
        if (/^@@ -\S+ \+(\d+)/) {
            $lineno = $1 - 1;
            next;
        }
        if (/^ /) {
            $lineno++;
            next;
        }
        if (s/^\+//) {
            $lineno++;
            chomp;
            if (/   /) {
                bad_line("TAB character", $_);
            }
        }
    }
    exit($found_bad);
'

It's not exactly what you asked for since it doesn't do any filename checking, but hopefully it helps regardless.