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Convert cksum(1) to use FILE * instead of an fd

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In sbase we generally do I/O through FILE * instead of file
descriptors directly.

Do not error out on the first file that can't be opened.
This commit is contained in:
sin 2013-11-12 11:16:13 +00:00
parent cfe5e9ef3a
commit 8fdfa7caeb
1 changed files with 23 additions and 16 deletions
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39
cksum.c
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@ -1,11 +1,11 @@
/* See LICENSE file for copyright and license details. */ /* See LICENSE file for copyright and license details. */
#include <fcntl.h> #include <errno.h>
#include <stdio.h> #include <stdio.h>
#include <stdlib.h> #include <stdlib.h>
#include <unistd.h> #include <string.h>
#include "util.h" #include "util.h"
static void cksum(int, const char *); static void cksum(FILE *, const char *);
static void usage(void); static void usage(void);
static const unsigned long crctab[] = { 0x00000000, static const unsigned long crctab[] = { 0x00000000,
@ -65,36 +65,43 @@ static const unsigned long crctab[] = { 0x00000000,
int int
main(int argc, char *argv[]) main(int argc, char *argv[])
{ {
int i, fd; FILE *fp;
ARGBEGIN { ARGBEGIN {
default: default:
usage(); usage();
} ARGEND; } ARGEND;
if(argc == 0) if(argc == 0) {
cksum(STDIN_FILENO, NULL); cksum(stdin, NULL);
else for(i = 0; i < argc; i++) { } else {
if((fd = open(argv[i], O_RDONLY)) == -1) for(; argc > 0; argc--, argv++) {
eprintf("open %s:", argv[i]); if (!(fp = fopen(argv[0], "r"))) {
cksum(fd, argv[i]); fprintf(stderr, "fopen %s: %s\n", argv[0],
close(fd); strerror(errno));
continue;
}
cksum(fp, argv[0]);
fclose(fp);
}
} }
return EXIT_SUCCESS; return EXIT_SUCCESS;
} }
void void
cksum(int fd, const char *s) cksum(FILE *fp, const char *s)
{ {
unsigned char buf[BUFSIZ]; unsigned char buf[BUFSIZ];
unsigned int ck = 0; unsigned int ck = 0;
size_t len; size_t len = 0;
int i, n; size_t i, n;
for(len = 0; (n = read(fd, buf, sizeof buf)) > 0; len += n) while ((n = fread(buf, 1, sizeof(buf), fp)) > 0) {
for(i = 0; i < n; i++) for(i = 0; i < n; i++)
ck = (ck << 8) ^ crctab[(ck >> 24) ^ buf[i]]; ck = (ck << 8) ^ crctab[(ck >> 24) ^ buf[i]];
if(n < 0) len += n;
}
if (ferror(fp))
eprintf("%s: read error:", s ? s : "<stdin>"); eprintf("%s: read error:", s ? s : "<stdin>");
for(i = len; i > 0; i >>= 8) for(i = len; i > 0; i >>= 8)