contrib/hooks/setgitperms.perl

   1 #!/usr/bin/perl
   2 #
   3 # Copyright (c) 2006 Josh England
   4 #
   5 # This script can be used to save/restore full permissions and ownership data
   6 # within a git working tree.
   7 #
   8 # To save permissions/ownership data, place this script in your .git/hooks
   9 # directory and enable a `pre-commit` hook with the following lines:
  10 #      #!/bin/sh
  11 #     . git-sh-setup
  12 #     $GIT_DIR/hooks/setgitperms.perl -r
  13 #
  14 # To restore permissions/ownership data, place this script in your .git/hooks
  15 # directory and enable a `post-merge` hook with the following lines:
  16 #      #!/bin/sh
  17 #     . git-sh-setup
  18 #     $GIT_DIR/hooks/setgitperms.perl -w
  19 #
  20 use strict;
  21 use Getopt::Long;
  22 use File::Find;
  23 use File::Basename;
  24
  25 my $usage =
  26 "Usage: setgitperms.perl [OPTION]... <--read|--write>
  27 This program uses a file `.gitmeta` to store/restore permissions and uid/gid
  28 info for all files/dirs tracked by git in the repository.
  29
  30 ---------------------------------Read Mode-------------------------------------
  31 -r,  --read         Reads perms/etc from working dir into a .gitmeta file
  32 -s,  --stdout       Output to stdout instead of .gitmeta
  33 -d,  --diff         Show unified diff of perms file (XOR with --stdout)
  34
  35 ---------------------------------Write Mode------------------------------------
  36 -w,  --write        Modify perms/etc in working dir to match the .gitmeta file
  37 -v,  --verbose      Be verbose
  38
  39 \n";
  40
  41 my ($stdout, $showdiff, $verbose, $read_mode, $write_mode);
  42
  43 if ((@ARGV < 0) || !GetOptions(
  44                                "stdout",         \$stdout,
  45                                "diff",           \$showdiff,
  46                                "read",           \$read_mode,
  47                                "write",          \$write_mode,
  48                                "verbose",        \$verbose,
  49                               )) { die $usage; }
  50 die $usage unless ($read_mode xor $write_mode);
  51
  52 my $topdir = `git-rev-parse --show-cdup` or die "\n"; chomp $topdir;
  53 my $gitdir = $topdir . '.git';
  54 my $gitmeta = $topdir . '.gitmeta';
  55
  56 if ($write_mode) {
  57     # Update the working dir permissions/ownership based on data from .gitmeta
  58     open (IN, "<$gitmeta") or die "Could not open $gitmeta for reading: $!\n";
  59     while (defined ($_ = <IN>)) {
  60         chomp;
  61         if (/^(.*)  mode=(\S+)\s+uid=(\d+)\s+gid=(\d+)/) {
  62             # Compare recorded perms to actual perms in the working dir
  63             my ($path, $mode, $uid, $gid) = ($1, $2, $3, $4);
  64             my $fullpath = $topdir . $path;
  65             my (undef,undef,$wmode,undef,$wuid,$wgid) = lstat($fullpath);
  66             $wmode = sprintf "%04o", $wmode & 07777;
  67             if ($mode ne $wmode) {
  68                 $verbose && print "Updating permissions on $path: old=$wmode, new=$mode\n";
  69                 chmod oct($mode), $fullpath;
  70             }
  71             if ($uid != $wuid || $gid != $wgid) {
  72                 if ($verbose) {
  73                     # Print out user/group names instead of uid/gid
  74                     my $pwname  = getpwuid($uid);
  75                     my $grpname  = getgrgid($gid);
  76                     my $wpwname  = getpwuid($wuid);
  77                     my $wgrpname  = getgrgid($wgid);
  78                     $pwname = $uid if !defined $pwname;
  79                     $grpname = $gid if !defined $grpname;
  80                     $wpwname = $wuid if !defined $wpwname;
  81                     $wgrpname = $wgid if !defined $wgrpname;
  82
  83                     print "Updating uid/gid on $path: old=$wpwname/$wgrpname, new=$pwname/$grpname\n";
  84                 }
  85                 chown $uid, $gid, $fullpath;
  86             }
  87         }
  88         else {
  89             warn "Invalid input format in $gitmeta:\n\t$_\n";
  90         }
  91     }
  92     close IN;
  93 }
  94 elsif ($read_mode) {
  95     # Handle merge conflicts in the .gitperms file
  96     if (-e "$gitdir/MERGE_MSG") {
  97         if (`grep ====== $gitmeta`) {
  98             # Conflict not resolved -- abort the commit
  99             print "PERMISSIONS/OWNERSHIP CONFLICT\n";
 100             print "    Resolve the conflict in the $gitmeta file and then run\n";
 101             print "    `.git/hooks/setgitperms.perl --write` to reconcile.\n";
 102             exit 1;
 103         }
 104         elsif (`grep $gitmeta $gitdir/MERGE_MSG`) {
 105             # A conflict in .gitmeta has been manually resolved. Verify that
 106             # the working dir perms matches the current .gitmeta perms for
 107             # each file/dir that conflicted.
 108             # This is here because a `setgitperms.perl --write` was not
 109             # performed due to a merge conflict, so permissions/ownership
 110             # may not be consistent with the manually merged .gitmeta file.
 111             my @conflict_diff = `git show \$(cat $gitdir/MERGE_HEAD)`;
 112             my @conflict_files;
 113             my $metadiff = 0;
 114
 115             # Build a list of files that conflicted from the .gitmeta diff
 116             foreach my $line (@conflict_diff) {
 117                 if ($line =~ m|^diff --git a/$gitmeta b/$gitmeta|) {
 118                     $metadiff = 1;
 119                 }
 120                 elsif ($line =~ /^diff --git/) {
 121                     $metadiff = 0;
 122                 }
 123                 elsif ($metadiff && $line =~ /^\+(.*)  mode=/) {
 124                     push @conflict_files, $1;
 125                 }
 126             }
 127
 128             # Verify that each conflict file now has permissions consistent
 129             # with the .gitmeta file
 130             foreach my $file (@conflict_files) {
 131                 my $absfile = $topdir . $file;
 132                 my $gm_entry = `grep "^$file  mode=" $gitmeta`;
 133                 if ($gm_entry =~ /mode=(\d+)  uid=(\d+)  gid=(\d+)/) {
 134                     my ($gm_mode, $gm_uid, $gm_gid) = ($1, $2, $3);
 135                     my (undef,undef,$mode,undef,$uid,$gid) = lstat("$absfile");
 136                     $mode = sprintf("%04o", $mode & 07777);
 137                     if (($gm_mode ne $mode) || ($gm_uid != $uid)
 138                         || ($gm_gid != $gid)) {
 139                         print "PERMISSIONS/OWNERSHIP CONFLICT\n";
 140                         print "    Mismatch found for file: $file\n";
 141                         print "    Run `.git/hooks/setgitperms.perl --write` to reconcile.\n";
 142                         exit 1;
 143                     }
 144                 }
 145                 else {
 146                     print "Warning! Permissions/ownership no longer being tracked for file: $file\n";
 147                 }
 148             }
 149         }
 150     }
 151
 152     # No merge conflicts -- write out perms/ownership data to .gitmeta file
 153     unless ($stdout) {
 154         open (OUT, ">$gitmeta.tmp") or die "Could not open $gitmeta.tmp for writing: $!\n";
 155     }
 156
 157     my @files = `git-ls-files`;
 158     my %dirs;
 159
 160     foreach my $path (@files) {
 161         chomp $path;
 162         # We have to manually add stats for parent directories
 163         my $parent = dirname($path);
 164         while (!exists $dirs{$parent}) {
 165             $dirs{$parent} = 1;
 166             next if $parent eq '.';
 167             printstats($parent);
 168             $parent = dirname($parent);
 169         }
 170         # Now the git-tracked file
 171         printstats($path);
 172     }
 173
 174     # diff the temporary metadata file to see if anything has changed
 175     # If no metadata has changed, don't overwrite the real file
 176     # This is just so `git commit -a` doesn't try to commit a bogus update
 177     unless ($stdout) {
 178         if (! -e $gitmeta) {
 179             rename "$gitmeta.tmp", $gitmeta;
 180         }
 181         else {
 182             my $diff = `diff -U 0 $gitmeta $gitmeta.tmp`;
 183             if ($diff ne '') {
 184                 rename "$gitmeta.tmp", $gitmeta;
 185             }
 186             else {
 187                 unlink "$gitmeta.tmp";
 188             }
 189             if ($showdiff) {
 190                 print $diff;
 191             }
 192         }
 193         close OUT;
 194     }
 195     # Make sure the .gitmeta file is tracked
 196     system("git add $gitmeta");
 197 }
 198
 199
 200 sub printstats {
 201     my $path = $_[0];
 202     $path =~ s/@/\@/g;
 203     my (undef,undef,$mode,undef,$uid,$gid) = lstat($path);
 204     $path =~ s/%/\%/g;
 205     if ($stdout) {
 206         print $path;
 207         printf "  mode=%04o  uid=$uid  gid=$gid\n", $mode & 07777;
 208     }
 209     else {
 210         print OUT $path;
 211         printf OUT "  mode=%04o  uid=$uid  gid=$gid\n", $mode & 07777;
 212     }
 213 }