A perl script for hooking into a Mercurial hook event. -In it's current form it will make a backup, convert indenting to tabs, and lint check php files. -Allows for anonymous subs to be passed as adhoc filters.

hghookscript.pl

###  
### HG Hook script
###  - allows filtering and other actions to be
###    run at a designated hook.  
### 

# a copy of each file along with it's directory structure
# is placed here when the script is initially run.
$BACKUP_DIR = "~/_hg_modified";

## initializing stuff
mkdir $BACKUP_DIR;
$CWD = `pwd`;
chomp $CWD;
@FILES = map { /^. (.+)$/; "$CWD/$1"; } split "\n", `hg st`;
exit unless @FILES;
## end initializing stuff


#########################################################
#########################################################
#########################################################
## User defined filters here

# first backup each file
filter(sub {
  (undef,$file,$filename,$dir) = @_;
  `mkdir -p $BACKUP_DIR$dir`;
  `cp $file $BACKUP_DIR$dir/$filename`;
  return;
});

# process tabs and spaces
filter(sub {
  return unless $_[1] =~ /\.(php|js|html|pl)$/i;
  return map { s/(^|\G)(  |\t)/\t/g; $_; } @{$_[0]};
});

# output the post processing diff
print `hg diff` || "<<NO DIFF>>\n";

# lint check php files
filter(sub {
  $file = $_[1];
  print `php -l $file` if $file =~ /\.php$/i;
  return;
});

#########################################################
#########################################################
#########################################################



## Final actions
print `\nread -p "Continue? [Enter|CTRL+C]"`;
## end Final actions



# filter handler
# -takes a single function
# --params available to function: ref @data, $file (full path), $filename, $dir
# -must return void to disable writing output
sub filter {
  my $func = shift;

  foreach my $file (@FILES) {
    my ($filename) = ($file =~ m|([^/]+)$|);
    my ($dir) = ($file =~ m|^(.+)/[^/]+$|);

    # modify the file
    open IN, $file or die "Cannot open for reading $file: $!";
    my @data = <IN>;
    close IN;
    
    my @newdata = &$func(\@data,$file,$filename,$dir);
    
    if (@newdata) {
      open OUT, ">$file" or die "Cannot open for writing $file: $!";
      print OUT @newdata;
      close OUT;
    }
  }
}