support reading from stdin

2 files changed, 6 insertions, 1 deletions

diff --git a/README.md b/README.md
index fe7892e..1375770 100644
--- a/README.md
+++ b/README.md
@@ -51,6 +51,7 @@ Examples:
 ```
 bin/sha1dcsum test/sha1_reducedsha_coll.bin test/shattered-1.pdf
 bin/sha1dcsum_partialcoll test/sha1reducedsha_coll.bin test/shattered-1.pdf
+pipe_data | bin/sha1dcsum -
 ```
 
 ## Library usage
diff --git a/src/main.c b/src/main.c
index 0db21a5..e594830 100644
--- a/src/main.c
+++ b/src/main.c
@@ -60,7 +60,11 @@ int main(int argc, char** argv)
 			SHA1DCSetDetectReducedRoundCollision(&ctx2, 1);
 		}
 
-		fd = fopen(argv[i], "rb");
+		if(!strcmp(argv[i],"-")) {
+			fd = stdin;
+		} else {
+			fd = fopen(argv[i], "rb");
+		}
 		if (fd == NULL)
 		{
 			fprintf(stderr, "cannot open file: %s: %s\n", argv[i], strerror(errno));