sparse-checkout: add '--stdin' option to set subcommand

The 'git sparse-checkout set' subcommand takes a list of patterns
and places them in the sparse-checkout file. Then, it updates the
working directory to match those patterns. For a large list of
patterns, the command-line call can get very cumbersome.

Add a '--stdin' option to instead read patterns over standard in.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 32 insertions, 2 deletions

diff --git a/builtin/sparse-checkout.c b/builtin/sparse-checkout.c
index 95cbd0a42c..82bff0020d 100644
--- a/builtin/sparse-checkout.c
+++ b/builtin/sparse-checkout.c
@@ -150,6 +150,15 @@ static int write_patterns_and_update(struct pattern_list *pl)
 	return update_working_directory();
 }
 
+static char const * const builtin_sparse_checkout_set_usage[] = {
+	N_("git sparse-checkout set (--stdin | <patterns>)"),
+	NULL
+};
+
+static struct sparse_checkout_set_opts {
+	int use_stdin;
+} set_opts;
+
 static int sparse_checkout_set(int argc, const char **argv, const char *prefix)
 {
 	static const char *empty_base = "";
@@ -157,10 +166,31 @@ static int sparse_checkout_set(int argc, const char **argv, const char *prefix)
 	struct pattern_list pl;
 	int result;
 	int changed_config = 0;
+
+	static struct option builtin_sparse_checkout_set_options[] = {
+		OPT_BOOL(0, "stdin", &set_opts.use_stdin,
+			 N_("read patterns from standard in")),
+		OPT_END(),
+	};
+
 	memset(&pl, 0, sizeof(pl));
 
-	for (i = 1; i < argc; i++)
-		add_pattern(argv[i], empty_base, 0, &pl, 0);
+	argc = parse_options(argc, argv, prefix,
+			     builtin_sparse_checkout_set_options,
+			     builtin_sparse_checkout_set_usage,
+			     PARSE_OPT_KEEP_UNKNOWN);
+
+	if (set_opts.use_stdin) {
+		struct strbuf line = STRBUF_INIT;
+
+		while (!strbuf_getline(&line, stdin)) {
+			char *buf = strbuf_detach(&line, NULL);
+			add_pattern(buf, empty_base, 0, &pl, 0);
+		}
+	} else {
+		for (i = 0; i < argc; i++)
+			add_pattern(argv[i], empty_base, 0, &pl, 0);
+	}
 
 	if (!core_apply_sparse_checkout) {
 		set_config(MODE_ALL_PATTERNS);