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Audit cmp(1)

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1) Remove the return-value-enum, which is not necessary for a simple
   program like this.
2) Don't disallow both l and s to be specified. This is undefined
   behaviour defined by POSIX, so we don't start demanding things
   from the user.
3) Replace exit() with return (we are in main).
4) Refactor main loop to never return in the loop, but actually
   set the same-value and break, which increases readability.
5) Remove the final fclose()'s. The OS will take care of them, no
   need to become cleansy here.
6) Use idiomatic return-value using same. This concludes the
   increase of readability in the main-loop.
This commit is contained in:
FRIGN 2015-03-11 11:16:40 +01:00
parent 833c2aebb4
commit 695153ac18
2 changed files with 15 additions and 21 deletions
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2
README
View File

@ -17,7 +17,7 @@ The following tools are implemented ('*' == finished, '#' == UTF-8 support,
=*| chown yes none
=*| chroot non-posix none
=*| cksum yes none
=* cmp yes none
=*| cmp yes none
#*| cols non-posix none
col yes none
=* comm yes none

34
cmp.c
View File

@ -4,12 +4,10 @@
#include "util.h"
enum { Same = 0, Diff = 1, Error = 2 };
static void
usage(void)
{
enprintf(Error, "usage: %s [-l | -s] file1 file2\n", argv0);
enprintf(2, "usage: %s [-l | -s] file1 file2\n", argv0);
}
int
@ -30,7 +28,7 @@ main(int argc, char *argv[])
usage();
} ARGEND;
if (argc != 2 || (lflag && sflag))
if (argc != 2)
usage();
for (n = 0; n < 2; n++) {
@ -38,11 +36,10 @@ main(int argc, char *argv[])
argv[n] = "<stdin>";
fp[n] = stdin;
} else {
fp[n] = fopen(argv[n], "r");
if (!fp[n]) {
if (!(fp[n] = fopen(argv[n], "r"))) {
if (!sflag)
weprintf("fopen %s:", argv[n]);
exit(Error);
return 2;
}
}
}
@ -57,25 +54,22 @@ main(int argc, char *argv[])
else if (b[0] == '\n')
line++;
continue;
}
if (b[0] == EOF || b[1] == EOF) {
} else if (b[0] == EOF || b[1] == EOF) {
if (!sflag)
fprintf(stderr, "cmp: EOF on %s\n",
argv[(b[0] == EOF) ? 0 : 1]);
exit(Diff);
}
if (!lflag) {
weprintf("cmp: EOF on %s\n", argv[(b[0] != EOF)]);
same = 0;
break;
} else if (!lflag) {
if (!sflag)
printf("%s %s differ: byte %ld, line %ld\n",
printf("%s %s differ: byte %zu, line %zu\n",
argv[0], argv[1], n, line);
exit(Diff);
same = 0;
break;
} else {
printf("%ld %o %o\n", n, b[0], b[1]);
printf("%zu %o %o\n", n, b[0], b[1]);
same = 0;
}
}
fclose(fp[0]);
fclose(fp[1]);
return same ? Same : Diff;
return !same;
}