feat: handle Ctrl+C gracefully, cleaning up partial output

tools/fpack.c

@@ -6,6 +6,7 @@
 #include "fpk.h"
 #include <dirent.h>
 #include <getopt.h>
+#include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -100,6 +101,13 @@ static void format_duration(double secs, char *buf, size_t bufsize)
 static unsigned char flags;
 static uint64_t entry_count;
 static uint64_t total_bytes;
+static volatile sig_atomic_t interrupted;
+
+static void handle_sigint(int sig)
+{
+	(void)sig;
+	interrupted = 1;
+}
 
 static struct option long_opts[] = {
 	{"output",   required_argument, NULL, 'o'},
@@ -229,6 +237,9 @@ static int add_file(struct fpk_writer *w, const char *path, size_t base_len)
 	size_t size;
 	char *norm;
 
+	if (interrupted)
+		return 0;
+
 	while (*rel_path == '/')
 		rel_path++;
 
@@ -439,8 +450,16 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
+	signal(SIGINT, handle_sigint);
+
 	if (!add_dir(w, input_dir, base_len)) {
 		fpk_writer_close(w);
+		if (interrupted) {
+			remove(output);
+			fprintf(stderr, "\nfpack: interrupted, removed incomplete archive: %s\n", output);
+			free(output);
+			return 130;
+		}
 		free(output);
 		return 1;
 	}