Add -f (fix EOF junk) option to unalf.

1 files changed, 15 insertions, 4 deletions

diff --git a/src/io.c b/src/io.c
index 4e20505..53bc0dd 100644
--- a/src/io.c
+++ b/src/io.c
@@ -14,8 +14,16 @@ static void die_not_alf(void) {
 	exit(1);
 }
 
-static void eof_junk(void) {
-	fprintf(stderr, "%s: junk at EOF (ignoring)\n", self);
+/* truncating the file by name could be a race condition, but I don't
+   think it's going to be a real-world problem for anyone. */
+static void eof_junk(long pos) {
+	fprintf(stderr, "%s: junk at EOF (%s)\n", self, opts.fixjunk ? "removing" : "ignoring");
+	if(opts.fixjunk) {
+		if(truncate(in_filename, pos) < 0) {
+			fprintf(stderr, "%s: could not remove junk: ", self);
+			perror(in_filename);
+		}
+	}
 }
 
 static void check_hdr_size(const char *name, unsigned long size) {
@@ -49,6 +57,9 @@ static void sanity_check_header(void) {
 int read_alf_header(void) {
 	u8 h1, h2;
 	int bytes;
+	long read_pos;
+
+	read_pos = ftell(in_file);
 
 	bytes = fread(mem + alf_header, 1, 29, in_file);
 
@@ -59,7 +70,7 @@ int read_alf_header(void) {
 			die_not_alf();
 	} else if(bytes < 29) {
 		if(headers_read) {
-			eof_junk();
+			eof_junk(read_pos);
 			return 0;
 		} else {
 			die_not_alf();
@@ -79,7 +90,7 @@ int read_alf_header(void) {
 	}
 
 	if(headers_read)
-		eof_junk();
+		eof_junk(read_pos);
 	else
 		die_not_alf();