(Slightly) More advanced detection of input file type

git-svn-id: svn://cook.msm.cam.ac.uk:745/diff-tomo/dtr@21 bf6ca9ba-c028-0410-8290-897cf20841d1

1 files changed, 27 insertions, 0 deletions

diff --git a/src/cache.c b/src/cache.c
index 61fe4bd..f1998b7 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -90,3 +90,30 @@ int cache_save(const char *filename, ReflectionContext *rctx) {
 	return 0;
 	
 }
+
+unsigned int cache_is_cachefile(const char *filename) {
+
+	FILE *fh;
+	CacheHeader ch;
+	size_t nread;
+
+	fh = fopen(filename, "rb");
+	nread = fread(&ch, sizeof(CacheHeader), 1, fh);
+	fclose(fh);
+
+	if ( nread != 1 ) {
+		return 0;
+	}
+	
+	if ( strncmp(ch.top, "DTRCACHE", 8) == 0 ) {
+		return 1;
+	}
+	
+	/* Backwards compatability */
+	if ( strncmp(ch.top, "DTR-CACHE", 9) == 0 ) {
+		return 1;
+	}
+	
+	return 0;
+
+}