(have_read_stdin, bsd_sum_file, sysv_sum_file,

main): Use bool for booleans.
(main): Don't dump core if invoked with argv[0]==NULL.

src/sum.c

@@ -37,8 +37,8 @@
 /* The name this program was run with. */
 char *program_name;
 
-/* Nonzero if any of the files read were the standard input. */
-static int have_read_stdin;
+/* True if any of the files read were the standard input. */
+static bool have_read_stdin;
 
 static struct option const longopts[] =
 {
@@ -80,10 +80,10 @@ With no FILE, or when FILE is -, read standard input.\n\
 /* Calculate and print the rotated checksum and the size in 1K blocks
    of file FILE, or of the standard input if FILE is "-".
    If PRINT_NAME is >1, print FILE next to the checksum and size.
-   The checksum varies depending on sizeof(int).
-   Return 0 if successful, -1 if an error occurs. */
+   The checksum varies depending on sizeof (int).
+   Return true if successful.  */
 
-static int
+static bool
 bsd_sum_file (const char *file, int print_name)
 {
   register FILE *fp;
@@ -95,7 +95,7 @@ bsd_sum_file (const char *file, int print_name)
   if (STREQ (file, "-"))
     {
       fp = stdin;
-      have_read_stdin = 1;
+      have_read_stdin = true;
     }
   else
     {
@@ -103,7 +103,7 @@ bsd_sum_file (const char *file, int print_name)
       if (fp == NULL)
 	{
 	  error (0, errno, "%s", file);
-	  return -1;
+	  return false;
 	}
     }
   /* Need binary I/O, or else byte counts and checksums are incorrect.  */
@@ -122,13 +122,13 @@ bsd_sum_file (const char *file, int print_name)
       error (0, errno, "%s", file);
       if (!STREQ (file, "-"))
 	fclose (fp);
-      return -1;
+      return false;
     }
 
   if (!STREQ (file, "-") && fclose (fp) == EOF)
     {
       error (0, errno, "%s", file);
-      return -1;
+      return false;
     }
 
   printf ("%05d %5s", checksum,
@@ -137,15 +137,15 @@ bsd_sum_file (const char *file, int print_name)
     printf (" %s", file);
   putchar ('\n');
 
-  return 0;
+  return true;
 }
 
 /* Calculate and print the checksum and the size in 512-byte blocks
    of file FILE, or of the standard input if FILE is "-".
    If PRINT_NAME is >0, print FILE next to the checksum and size.
-   Return 0 if successful, -1 if an error occurs. */
+   Return true if successful.  */
 
-static int
+static bool
 sysv_sum_file (const char *file, int print_name)
 {
   int fd;
@@ -161,7 +161,7 @@ sysv_sum_file (const char *file, int print_name)
   if (STREQ (file, "-"))
     {
       fd = 0;
-      have_read_stdin = 1;
+      have_read_stdin = true;
     }
   else
     {
@@ -169,7 +169,7 @@ sysv_sum_file (const char *file, int print_name)
       if (fd == -1)
 	{
 	  error (0, errno, "%s", file);
-	  return -1;
+	  return false;
 	}
     }
   /* Need binary I/O, or else byte counts and checksums are incorrect.  */
@@ -188,7 +188,7 @@ sysv_sum_file (const char *file, int print_name)
 	  error (0, errno, "%s", file);
 	  if (!STREQ (file, "-"))
 	    close (fd);
-	  return -1;
+	  return false;
 	}
 
       for (i = 0; i < bytes_read; i++)
@@ -199,7 +199,7 @@ sysv_sum_file (const char *file, int print_name)
   if (!STREQ (file, "-") && close (fd) == -1)
     {
       error (0, errno, "%s", file);
-      return -1;
+      return false;
     }
 
   r = (s & 0xffff) + ((s & 0xffffffff) >> 16);
@@ -211,16 +211,16 @@ sysv_sum_file (const char *file, int print_name)
     printf (" %s", file);
   putchar ('\n');
 
-  return 0;
+  return true;
 }
 
 int
 main (int argc, char **argv)
 {
-  int errors = 0;
+  bool ok;
   int optc;
   int files_given;
-  int (*sum_func) (const char *, int) = bsd_sum_file;
+  bool (*sum_func) (const char *, int) = bsd_sum_file;
 
   initialize_main (&argc, &argv);
   program_name = argv[0];
@@ -230,7 +230,7 @@ main (int argc, char **argv)
 
   atexit (close_stdout);
 
-  have_read_stdin = 0;
+  have_read_stdin = false;
 
   while ((optc = getopt_long (argc, argv, "rs", longopts, NULL)) != -1)
     {
@@ -257,17 +257,13 @@ main (int argc, char **argv)
     }
 
   files_given = argc - optind;
-  if (files_given == 0)
-    {
-      if ((*sum_func) ("-", files_given) < 0)
-	errors = 1;
-    }
+  if (files_given <= 0)
+    ok = sum_func ("-", files_given);
   else
-    for (; optind < argc; optind++)
-      if ((*sum_func) (argv[optind], files_given) < 0)
-	errors = 1;
+    for (ok = true; optind < argc; optind++)
+      ok &= sum_func (argv[optind], files_given);
 
   if (have_read_stdin && fclose (stdin) == EOF)
     error (EXIT_FAILURE, errno, "-");
-  exit (errors == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
+  exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);
 }