send-email: teach git send-email option to translate aliases

git send-email has support for converting shorthand alias names to
canonical email addresses via the alias file. It supports a wide variety
of alias file formats based on popular email program file formats.

Other programs, such as b4, would like the ability to convert aliases in
the same way as git send-email without needing to re-implement the logic
for understanding the many file formats.

Teach git send-email a new option, --translate-aliases, which will
enable this functionality. Similar to --dump-aliases, this option works
like a new mode of operation for git send-email.

When run with --translate-aliases, git send-email reads from standard
input and converts any provided alias into its canonical name and email
according to the alias file. Each expanded name and address is printed
to standard output, one per line.

Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 20 insertions, 1 deletions

diff --git a/git-send-email.perl b/git-send-email.perl
index 72044e5ef3..cdcee1d0cf 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -31,6 +31,7 @@ sub usage {
 git send-email [<options>] <file|directory>
 git send-email [<options>] <format-patch options>
 git send-email --dump-aliases
+git send-email --translate-aliases
 
   Composing:
     --from                  <str>  * Email From:
@@ -99,6 +100,10 @@ git send-email --dump-aliases
 
   Information:
     --dump-aliases                 * Dump configured aliases and exit.
+    --translate-aliases            * Translate aliases read from standard
+                                     input according to the configured email
+                                     alias file(s), outputting the result to
+                                     standard output.
 
 EOT
 	exit(1);
@@ -212,6 +217,7 @@ my $format_patch;
 my $compose_filename;
 my $force = 0;
 my $dump_aliases = 0;
+my $translate_aliases = 0;
 
 # Variables to prevent short format-patch options from being captured
 # as abbreviated send-email options
@@ -476,11 +482,14 @@ my $git_completion_helper;
 my %dump_aliases_options = (
 	"h" => \$help,
 	"dump-aliases" => \$dump_aliases,
+	"translate-aliases" => \$translate_aliases,
 );
 $rc = GetOptions(%dump_aliases_options);
 usage() unless $rc;
 die __("--dump-aliases incompatible with other options\n")
-    if !$help and $dump_aliases and @ARGV;
+    if !$help and ($dump_aliases or $translate_aliases) and @ARGV;
+die __("--dump-aliases and --translate-aliases are mutually exclusive\n")
+    if !$help and $dump_aliases and $translate_aliases;
 my %options = (
 		    "sender|from=s" => \$sender,
 		    "in-reply-to=s" => \$initial_in_reply_to,
@@ -724,6 +733,16 @@ if ($dump_aliases) {
     exit(0);
 }
 
+if ($translate_aliases) {
+	while (<STDIN>) {
+		my @addr_list = parse_address_line($_);
+		@addr_list = expand_aliases(@addr_list);
+		@addr_list = sanitize_address_list(@addr_list);
+		print "$_\n" for @addr_list;
+	}
+	exit(0);
+}
+
 # is_format_patch_arg($f) returns 0 if $f names a patch, or 1 if
 # $f is a revision list specification to be passed to format-patch.
 sub is_format_patch_arg {