migrated htpasswd command from g2.

(with some fixups by committer)

src/commands/htpasswd

@@ -0,0 +1,44 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+
+use lib $ENV{GL_LIBDIR};
+use Gitolite::Rc;
+use Gitolite::Common;
+
+=for usage
+Usage:  ssh git@host htpasswd
+
+Sets your htpasswd, assuming your admin has enabled it.
+
+(Admins: You need to add HTPASSWD_FILE to the rc file, pointing to an
+existing, writable, but possibly an initially empty, file, as well as adding
+an entry for 'htpasswd' to the COMMANDS hash).
+=cut
+
+# usage and sanity checks
+usage() if @ARGV and $ARGV[0] eq '-h';
+$ENV{GL_USER} or _die "GL_USER not set";
+my $htpasswd_file = $rc{HTPASSWD_FILE} || '';
+die "htpasswd not enabled\n" unless $htpasswd_file;
+die "$htpasswd_file doesn't exist or is not writable\n" unless -w $htpasswd_file;
+
+# prompt
+$|++;
+print <<EOFhtp;
+Please type in your new htpasswd at the prompt.  You only have to type it once.
+
+NOTE THAT THE PASSWORD WILL BE ECHOED, so please make sure no one is
+shoulder-surfing, and make sure you clear your screen as well as scrollback
+history after you're done (or close your terminal instance).
+
+EOFhtp
+print "new htpasswd: ";
+
+# get the password and run htpasswd
+my $password = <>;
+$password =~ s/[\n\r]*$//;
+die "empty passwords are not allowed\n" unless $password;
+my $res = system("htpasswd", "-mb", $htpasswd_file, $ENV{GL_USER}, $password);
+die "htpasswd command seems to have failed with return code: $res.\n" if $res;