made die() variadic

src/card.c

@@ -19,7 +19,7 @@ CARD* card_parse_csv(char *f, int *ct) {
     CARD *ca = NULL;
 
     if ((fp = fopen(f, "r")) == NULL)
-        die("failed to open file (null pointer)");
+        die("failed to open file '%s' (null pointer)", f);
 
     *ct = 0;
 

src/include/main.h

@@ -1,7 +1,7 @@
 #ifndef MAIN_H
 #define MAIN_H
 
-void die(char *);
+void die(char *, ...);
 char *fgetl(FILE *);
 char *strdup_(char *);
 

src/main.c

@@ -1,13 +1,21 @@
 #include <stdio.h>
 #include <stdlib.h>
+#include <stdarg.h>
 #include <string.h>
 #include <ncurses.h>
 
 #include "include/main.h"
 #include "include/card.h"
 
-void die(char *s) {
-    fprintf(stderr, "fatal: %s\n", s);
+void die(char *format, ...) {
+    va_list args;
+    va_start(args, format);
+
+    fprintf(stderr, "fatal: ");
+    vfprintf(stderr, format, args);
+    fprintf(stderr, "\n");
+
+    va_end(args);
     exit(1);
 }
 
@@ -27,7 +35,8 @@ void usage(void) {
     exit(0);
 }
 
-char *fgetl(FILE *stream) { size_t s_sz = 1; // +1 for null byte
+char *fgetl(FILE *stream) {
+    size_t s_sz = 1; // +1 for null byte
     char *s = NULL;
     char c;