[hackers] [sbase] Audit cksum(1) || FRIGN

[git]

commit 468fa6db5186bdb4be3d6c899f1ffcb0bd0421ee
Author: FRIGN <d...@frign.de>
Date:   Wed Mar 11 00:13:48 2015 +0100

    Audit cksum(1)
    
    1) Reorder local variables.
    2) Cleanup error messages, use %zu for size_t.
    3) combine putchar(' ') and fputs to substitute printf(" %s", s).
    4) Fix usage().
    5) argv-argc-usage-fix.
    6) Add empty line before return.

diff --git a/README b/README
index 2df3f42..f5a17bb 100644
--- a/README
+++ b/README
@@ -16,7 +16,7 @@ The following tools are implemented ('*' == finished, '#' == 
UTF-8 support,
 =*| chmod           yes                          none
 =*| chown           yes                          none
 =*| chroot          non-posix                    none
-=*  cksum           yes                          none
+=*| cksum           yes                          none
 =*  cmp             yes                          none
 #*| cols            non-posix                    none
     col             yes                          none
diff --git a/cksum.c b/cksum.c
index 6f099fa..59a4f88 100644
--- a/cksum.c
+++ b/cksum.c
@@ -61,32 +61,33 @@ static const unsigned long crctab[] = {         0x00000000,
 static void
 cksum(FILE *fp, const char *s)
 {
-       unsigned char buf[BUFSIZ];
+       size_t len = 0, i, n;
        uint32_t ck = 0;
-       size_t len = 0;
-       size_t i, n;
+       unsigned char buf[BUFSIZ];
 
-       while ((n = fread(buf, 1, sizeof(buf), fp)) > 0) {
+       while ((n = fread(buf, 1, sizeof(buf), fp))) {
                for (i = 0; i < n; i++)
                        ck = (ck << 8) ^ crctab[(ck >> 24) ^ buf[i]];
                len += n;
        }
        if (ferror(fp))
-               eprintf("%s: read error:", s ? s : "<stdin>");
+               eprintf("fread %s:", s ? s : "<stdin>");
 
-       for (i = len; i > 0; i >>= 8)
+       for (i = len; i; i >>= 8)
                ck = (ck << 8) ^ crctab[(ck >> 24) ^ (i & 0xFF)];
 
-       printf("%"PRIu32" %lu", ~ck, (unsigned long)len);
-       if (s)
-               printf(" %s", s);
+       printf("%"PRIu32" %zu", ~ck, len);
+       if (s) {
+               putchar(' ');
+               fputs(s, stdout);
+       }
        putchar('\n');
 }
 
 static void
 usage(void)
 {
-       eprintf("usage: %s [files ...]\n", argv0);
+       eprintf("usage: %s [file ...]\n", argv0);
 }
 
 int
@@ -99,17 +100,18 @@ main(int argc, char *argv[])
                usage();
        } ARGEND;
 
-       if (argc == 0)
+       if (!argc) {
                cksum(stdin, NULL);
-       else {
-               for (; argc > 0; argc--, argv++) {
-                       if (!(fp = fopen(argv[0], "r"))) {
-                               weprintf("fopen %s:", argv[0]);
+       } else {
+               for (; *argv; argc--, argv++) {
+                       if (!(fp = fopen(*argv, "r"))) {
+                               weprintf("fopen %s:", *argv);
                                continue;
                        }
-                       cksum(fp, argv[0]);
+                       cksum(fp, *argv);
                        fclose(fp);
                }
        }
+
        return 0;
 }