Added arbitary number of files to check

.gitignore

@@ -1,2 +1,3 @@
 obj/
 fcmp-*
+test/

Makefile

@@ -8,7 +8,7 @@ OPT_FLAGS+= -fgraphite
 RELEASE_CFLAGS?=  -O3 -march=native -flto $(OPT_FLAGS)
 RELEASE_LDFLAGS?= -O3 -flto
 
-DEBUG_CFLAGS?=  -O0 -g
+DEBUG_CFLAGS?=  -DDEBUG -O0 -g
 DEBUG_LDFLAGS?= -O0
 
 CFLAGS+= -Wall -pedantic --std=gnu11 $(addprefix -I,$(INCLUDE))

src/main.c

@@ -6,10 +6,17 @@
 
 static const char* _prog_name = "fcmp";
 
-__attribute__((noreturn)) void usage() 
+#ifdef DEBUG
+#define __name(d) #d
+#define dprintf(fmt, ...) printf("[dbg @" __FILE__ "->%s:%d] " fmt "\n", __func__, __LINE__ __VA_OPT__(,) __VA_ARGS__)
+#else
+#define dprintf(fmt, ...)
+#endif
+
+__attribute__((noreturn)) static void usage() 
 {
 	fprintf(stderr, "fcmp: compare files for identity\n");
-	fprintf(stderr, "usage: %s <file1> <file2>\n", _prog_name);
+	fprintf(stderr, "usage: %s <files...>\n", _prog_name);
 	exit(-1);
 }
 
@@ -19,37 +26,90 @@ __attribute__((always_inline)) static inline const void* die_if_null(const void*
 	else return ptr;
 }
 
+static int unmap_all(mmap_t ptrs[], size_t len)
+{
+	register int rval=1;
+	dprintf("Unmapping %lu entries", len);
+	for (register size_t i=0;i<len;i++)
+	{
+		if(!unmap_and_close(ptrs[i])) {
+			fprintf(stderr, "Failed to unmap and close fd %d", ptrs[i].fd);
+			rval = -1;
+		}
+	}
+	return rval;
+}
+
+static int compare_then_close(const mmap_t * restrict map1, mmap_t* restrict map2)
+{
+	register int rval=0;
+
+	if (map1->len != map2->len) rval = 2;
+	else if (memcmp(map1->ptr, map2->ptr, map1->len) != 0) rval = 1;
+
+	if(!unmap_and_close(*map2)) {
+		fprintf(stderr, "Failed to unmap and close");
+		rval=-1;
+	}
+
+	return rval;
+}
+
 int main(int argc, char** argv)
 {
 	_prog_name = argv[0];
 
+	const int nrest = argc-2;
+	if (nrest==0) usage();
+	dprintf("There are %d extra files to chk", nrest);
 	const char* f1 = die_if_null(argv[1]);
-	const char* f2 = die_if_null(argv[2]);
+	const char* frest[nrest];
+
+	for (register int i=0;i<nrest;i++) {
+		frest[i] = die_if_null(argv[2+i]);
+		dprintf("frest[%d] = \"%s\"", i, frest[i]);
+	}
+
+	mmap_t map1;
+	mmap_t mrest[nrest];
 
-	mmap_t map1, map2;
 	if (!open_and_map(f1, &map1)) {
 		fprintf(stderr, "Failed to open or map %s\n", f1);
 		return -1;
 	}
-	if (!open_and_map(f2, &map2)) {
-		fprintf(stderr, "Failed to open or map %s\n", f2);
-		unmap_and_close(map1);
-		return -1;
-	}
 
+	for(register int i=0;i<nrest;i++) {
+		const char* f2 = frest[i];
+		dprintf("Attempting to map %d (%s)", i, f2);
+		if (!open_and_map(f2, &mrest[i])) {
+			fprintf(stderr, "Failed to open or map arg %d, `%s`\n", i+2, f2);
+			unmap_and_close(map1);
+			unmap_all(mrest, i);
+			return -1;
+		}
+	}
+	dprintf("All map okay");
 	register int rval=0;
-	if (map1.len != map2.len) rval = 2;
-	else if (memcmp(map1.ptr, map2.ptr, map1.len) != 0) rval = 1;
 
-	if(!unmap_and_close(map1)) {
-		fprintf(stderr, "Failed to unmap and close %s", f1);
-		rval=-1;
+	for(register int i=0;i<nrest;i++) {
+		dprintf("Checking %d \"%s\"", i, frest[i]);
+		switch ((rval=compare_then_close(&map1, mrest+i))) {
+			case 0: break;
+			default:
+				// Close the rest
+				dprintf("Unmapping mrest from %d (len %d) while max of nrest is %d", (i+1), nrest-(i+1), nrest);
+				if(i<nrest-1) unmap_all(mrest+ (i+1), nrest- (i+1));
+				goto end;
+		}
+		dprintf("Ident %d OK", i); 
 	}
 
-	if(!unmap_and_close(map2)) {
-		fprintf(stderr, "Failed to unmap and close %s", f2);
+end:
+	if(!unmap_and_close(map1)) {
+		fprintf(stderr, "Failed to unmap and close %s", f1);
 		rval=-1;
 	}
 
+	dprintf("Final rval is %d", rval);
 	return rval;
 }