[dev] [sbase] [PATCH v2] tar: support -f - as stdin/out

---
 tar.1 |  4 +++-
 tar.c | 22 +++++++++++-----------
 2 files changed, 14 insertions(+), 12 deletions(-)
diff --git a/tar.1 b/tar.1
index 6341e17da4d0..ff6578b56d5c 100644
--- a/tar.1
+++ b/tar.1
_AT_@ -32,7 +32,9 @@ before beginning.
 .It Fl f Ar file
 Set
 .Ar file
-as input | output archive instead of stdin | stdout.
+as input | output archive instead of stdin | stdout. The -
+.Ar file
+is interpreted as stdin | stdout.
 .It Fl m
 Do not preserve modification time.
 .It Fl t
diff --git a/tar.c b/tar.c
index 8dbce22cc501..d8ab0db608f5 100644
--- a/tar.c
+++ b/tar.c
_AT_@ -541,12 +541,13 @@ main(int argc, char *argv[])
 	switch (mode) {
 	case 'c':
 		tarfd = 1;
-		if (file) {
-			tarfd = open(file, O_WRONLY | O_TRUNC | O_CREAT, 0644);
-			if (tarfd < 0)
-				eprintf("open %s:", file);
-			if (lstat(file, &st) < 0)
-				eprintf("lstat %s:", file);
+		if (!file || (file[0] == '-' && !file[1])) {
+			tarfd = 1;
+		} else if ((tarfd = open(file, O_WRONLY | O_TRUNC | O_CREAT, 0644)) < 0) {
+			eprintf("open %s:", file);
+		} else if (lstat(file, &st) < 0) {
+			eprintf("lstat %s:", file);
+		} else {
 			tarinode = st.st_ino;
 			tardev = st.st_dev;
 		}
_AT_@ -561,11 +562,10 @@ main(int argc, char *argv[])
 		break;
 	case 't':
 	case 'x':
-		tarfd = 0;
-		if (file) {
-			tarfd = open(file, O_RDONLY);
-			if (tarfd < 0)
-				eprintf("open %s:", file);
+		if (!file || (file[0] == '-' && !file[1])) {
+			tarfd = 0;
+		} else if ((tarfd = open(file, O_RDONLY)) < 0) {
+			eprintf("open %s:", file);
 		}
 
 		if (filtertool) {
-- 
2.4.0