[PATCH] git-diff-*: --name-only and --name-only-z.

Porcelain layers often want to find only names of changed files,
and even with diff-raw output format they end up having to pick
out only the filename.  Support --name-only (and --name-only-z
for xargs -0 and cpio -0 users that want to treat filenames with
embedded newlines sanely) flag to help them.

Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

6 files changed, 38 insertions, 1 deletions

diff --git a/diff-cache.c b/diff-cache.c
index 33b3b31779..e1ac57dde8 100644
--- a/diff-cache.c
+++ b/diff-cache.c
@@ -223,6 +223,14 @@ int main(int argc, const char **argv)
 			diff_output_format = DIFF_FORMAT_MACHINE;
 			continue;
 		}
+		if (!strcmp(arg, "--name-only")) {
+			diff_output_format = DIFF_FORMAT_NAME;
+			continue;
+		}
+		if (!strcmp(arg, "--name-only-z")) {
+			diff_output_format = DIFF_FORMAT_NAME_Z;
+			continue;
+		}
 		if (!strcmp(arg, "-R")) {
 			diff_setup_opt |= DIFF_SETUP_REVERSE;
 			continue;
diff --git a/diff-files.c b/diff-files.c
index 3221e31979..6d2aec3406 100644
--- a/diff-files.c
+++ b/diff-files.c
@@ -55,6 +55,10 @@ int main(int argc, const char **argv)
 			; /* no-op */
 		else if (!strcmp(argv[1], "-z"))
 			diff_output_format = DIFF_FORMAT_MACHINE;
+		else if (!strcmp(argv[1], "--name-only"))
+			diff_output_format = DIFF_FORMAT_NAME;
+		else if (!strcmp(argv[1], "--name-only-z"))
+			diff_output_format = DIFF_FORMAT_NAME_Z;
 		else if (!strcmp(argv[1], "-R"))
 			diff_setup_opt |= DIFF_SETUP_REVERSE;
 		else if (!strncmp(argv[1], "-S", 2))
diff --git a/diff-stages.c b/diff-stages.c
index 738fe5d987..9d33535fe0 100644
--- a/diff-stages.c
+++ b/diff-stages.c
@@ -87,6 +87,10 @@ int main(int ac, const char **av)
 			find_copies_harder = 1;
 		else if (!strcmp(arg, "-z"))
 			diff_output_format = DIFF_FORMAT_MACHINE;
+		else if (!strcmp(arg, "--name-only"))
+			diff_output_format = DIFF_FORMAT_NAME;
+		else if (!strcmp(arg, "--name-only-z"))
+			diff_output_format = DIFF_FORMAT_NAME_Z;
 		else if (!strcmp(arg, "-R"))
 			diff_setup_opt |= DIFF_SETUP_REVERSE;
 		else if (!strncmp(arg, "-S", 2))
diff --git a/diff-tree.c b/diff-tree.c
index ea237051ee..f499d2ead5 100644
--- a/diff-tree.c
+++ b/diff-tree.c
@@ -480,6 +480,14 @@ int main(int argc, const char **argv)
 			find_copies_harder = 1;
 			continue;
 		}
+		if (!strcmp(arg, "--name-only")) {
+			diff_output_format = DIFF_FORMAT_NAME;
+			continue;
+		}
+		if (!strcmp(arg, "--name-only-z")) {
+			diff_output_format = DIFF_FORMAT_NAME_Z;
+			continue;
+		}
 		if (!strcmp(arg, "-z")) {
 			diff_output_format = DIFF_FORMAT_MACHINE;
 			continue;
diff --git a/diff.c b/diff.c
index 36bbda6d8d..d0962bac96 100644
--- a/diff.c
+++ b/diff.c
@@ -818,6 +818,12 @@ static void diff_flush_raw(struct diff_filepair *p,
 	putchar(line_termination);
 }
 
+static void diff_flush_name(struct diff_filepair *p,
+			    int line_termination)
+{
+	printf("%s%c", p->two->path, line_termination);
+}
+
 int diff_unmodified_pair(struct diff_filepair *p)
 {
 	/* This function is written stricter than necessary to support
@@ -978,7 +984,8 @@ void diff_flush(int diff_output_style)
 	int line_termination = '\n';
 	int inter_name_termination = '\t';
 
-	if (diff_output_style == DIFF_FORMAT_MACHINE)
+	if (diff_output_style == DIFF_FORMAT_MACHINE ||
+	    diff_output_style == DIFF_FORMAT_NAME_Z)
 		line_termination = inter_name_termination = 0;
 
 	for (i = 0; i < q->nr; i++) {
@@ -997,6 +1004,10 @@ void diff_flush(int diff_output_style)
 			diff_flush_raw(p, line_termination,
 				       inter_name_termination);
 			break;
+		case DIFF_FORMAT_NAME:
+		case DIFF_FORMAT_NAME_Z:
+			diff_flush_name(p, line_termination);
+			break;
 		}
 	}
 	for (i = 0; i < q->nr; i++)
diff --git a/diff.h b/diff.h
index 9f0852d321..46c0e236c3 100644
--- a/diff.h
+++ b/diff.h
@@ -59,6 +59,8 @@ extern int diff_queue_is_empty(void);
 #define DIFF_FORMAT_MACHINE	1
 #define DIFF_FORMAT_PATCH	2
 #define DIFF_FORMAT_NO_OUTPUT	3
+#define DIFF_FORMAT_NAME	4
+#define DIFF_FORMAT_NAME_Z	5
 
 extern void diff_flush(int output_style);