added code to check to see if a file is an iso image

1 files changed, 35 insertions, 0 deletions

diff --git a/isys/isofs.c b/isys/isofs.c
new file mode 100644
index 000000000..5ba255ff9
--- /dev/null
+++ b/isys/isofs.c
@@ -0,0 +1,35 @@
+#include <fcntl.h>
+#include <string.h>
+#include <unistd.h>
+
+#define BLOCK_SIZE 2048
+ 
+int fileIsIso(const char * file) {
+    int blkNum;
+    char magic[5];
+    int fd;
+
+    fd = open(file, O_RDONLY);
+    if (fd < 0)
+	return 1;
+
+    for (blkNum = 16; blkNum < 100; blkNum++) {
+	if (lseek(fd, blkNum * BLOCK_SIZE + 1, SEEK_SET) < 0) {
+	    close(fd);
+	    return 1;
+	}
+
+	if (read(fd, magic, sizeof(magic)) != sizeof(magic)) {
+	    close(fd);
+	    return 1;
+	}
+
+	if (!strncmp(magic, "CD001", 5)) {
+	    close(fd);
+	    return 0;
+	}
+    }
+
+    close(fd); 
+    return 1;
+}