git-archive: add '-o' as a alias for '--output'

The '-o' option is commonly used in many tools to specify the output file.
Typing '--output' every time is a bit too long to be a practical alternative
to redirecting output. But specifying the output name has the advantage of
making possible to guess the desired output format by filename extension.

Signed-off-by: Dmitry Potapov <dpotapov@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-archive.txt

@@ -10,7 +10,7 @@ SYNOPSIS
 --------
 [verse]
 'git archive' [--format=<fmt>] [--list] [--prefix=<prefix>/] [<extra>]
-	      [--output=<file>] [--worktree-attributes]
+	      [-o | --output=<file>] [--worktree-attributes]
 	      [--remote=<repo> [--exec=<git-upload-archive>]] <tree-ish>
 	      [path...]
 
@@ -48,6 +48,7 @@ OPTIONS
 --prefix=<prefix>/::
 	Prepend <prefix>/ to each filename in the archive.
 
+-o <file>::
 --output=<file>::
 	Write the archive to <file> instead of stdout.
 

archive.c

@@ -283,7 +283,7 @@ static int parse_archive_args(int argc, const char **argv,
 		OPT_STRING(0, "format", &format, "fmt", "archive format"),
 		OPT_STRING(0, "prefix", &base, "prefix",
 			"prepend prefix to each pathname in the archive"),
-		OPT_STRING(0, "output", &output, "file",
+		OPT_STRING('o', "output", &output, "file",
 			"write the archive to this file"),
 		OPT_BOOLEAN(0, "worktree-attributes", &worktree_attributes,
 			"read .gitattributes in working directory"),

builtin-archive.c

@@ -71,7 +71,7 @@ int cmd_archive(int argc, const char **argv, const char *prefix)
 	const char *output = NULL;
 	const char *remote = NULL;
 	struct option local_opts[] = {
-		OPT_STRING(0, "output", &output, "file",
+		OPT_STRING('o', "output", &output, "file",
 			"write the archive to this file"),
 		OPT_STRING(0, "remote", &remote, "repo",
 			"retrieve the archive from remote repository <repo>"),