1 files changed, 11 insertions, 2 deletions
diff --git a/wk4/pset/recover/recover.c b/wk4/pset/recover/recover.c
index 3982f4f..474c4f8 100644
--- a/wk4/pset/recover/recover.c
+++ b/wk4/pset/recover/recover.c
@@ -3,12 +3,21 @@
 
 int main(int argc, char *argv[])
 {
+    if (argc > 1) {
+        printf("Usage: ./recover infile\n");
+        return 1;
+    }
+
     // Remember filenames
     char *infile = argv[optind];
 
     // Open input file
     FILE *inptr = fopen(infile, "r");
+    if (inptr == NULL)
+    {
+        printf("Could not open %s.\n", infile);
+        return 1;
+    }
 
-    
-    fread("card.raw", sizeof(RGBTRIPLE), width, inptr);
+    fread(infile, sizeof(RGBTRIPLE), width, inptr);
 }