[PATCH 4/5] mcookie: use control structure, and fix usage()

Sami Kerola
2014-03-08T21:43:38Z

misc-utils/mcookie.c | 95 +++++++++++++++++++++++++++-------------------------
1 file changed, 49 insertions(+), 46 deletions(-)

diff --git a/misc-utils/mcookie.c b/misc-utils/mcookie.c
index 9167440..31f33e4 100644
--- a/misc-utils/mcookie.c
+++ b/misc-utils/mcookie.c
@@ -38,78 +38,82 @@ enum {
RAND_BYTES = 128
};

+struct mcookie_control {
+ struct MD5Context ctx;
+ char **files;
+ int nfiles;
+ int fd;
+ unsigned int
+ verbose:1;
+};
+
/* The basic function to hash a file */
-static size_t hash_file(struct MD5Context *ctx, int fd)
+static size_t hash_file(struct mcookie_control *ctl)
{
size_t count = 0;
ssize_t r;
unsigned char buf[BUFFERSIZE];

- while ((r = read(fd, buf, sizeof(buf))) > 0) {
- MD5Update(ctx, buf, r);
+ while ((r = read(ctl->fd, buf, sizeof(buf))) > 0) {
+ MD5Update(&(ctl->ctx), buf, r);
count += r;
}
/* Separate files with a null byte */
buf[0] = '\0';
- MD5Update(ctx, buf, 1);
+ MD5Update(&(ctl->ctx), buf, 1);
return count;
}

static void __attribute__((__noreturn__)) usage(FILE * out)
{
- fputs(_("\nUsage:\n"), out);
- fprintf(out,
- _(" %s [options]\n"), program_invocation_short_name);
-
- fputs(_("\nOptions:\n"), out);
- fputs(_(" -f, --file <file> use file as a cookie seed\n"
- " -v, --verbose explain what is being done\n"
- " -V, --version output version information and exit\n"
- " -h, --help display this help and exit\n\n"), out);
-
+ fputs(USAGE_HEADER, out);
+ fprintf(out, _(" %s [options]\n"), program_invocation_short_name);
+ fputs(USAGE_OPTIONS, out);
+ fputs(_(" -f, --file <file> use file as a cookie seed\n"), out);
+ fputs(_(" -v, --verbose explain what is being done\n"), out);
+ fputs(USAGE_SEPARATOR, out);
+ fputs(USAGE_HELP, out);
+ fputs(USAGE_VERSION, out);
+ fprintf(out, USAGE_MAN_TAIL("mcookie(1)"));
exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
}

-static void randomness_from_files(char **files, int nfiles,
- struct MD5Context *ctx, int verbose)
+static void randomness_from_files(struct mcookie_control *ctl)
{
- int fd, i;
+ int i;
size_t count = 0;

- for (i = 0; i < nfiles; i++) {
- if (files[i][0] == '-' && !files[i][1])
- fd = STDIN_FILENO;
+ for (i = 0; i < ctl->nfiles; i++) {
+ if (ctl->files[i][0] == '-' && !ctl->files[i][1])
+ ctl->fd = STDIN_FILENO;
else
- fd = open(files[i], O_RDONLY);
+ ctl->fd = open(ctl->files[i], O_RDONLY);

- if (fd < 0) {
- warn(_("cannot open %s"), files[i]);
+ if (ctl->fd < 0) {
+ warn(_("cannot open %s"), ctl->files[i]);
} else {
- count = hash_file(ctx, fd);
- if (verbose)
+ count = hash_file(ctl);
+ if (ctl->verbose)
fprintf(stderr,
P_("Got %zu byte from %s\n",
"Got %zu bytes from %s\n", count),
- count, files[i]);
+ count, ctl->files[i]);

- if (fd != STDIN_FILENO)
- if (close(fd))
+ if (ctl->fd != STDIN_FILENO)
+ if (close(ctl->fd))
err(EXIT_FAILURE,
- _("closing %s failed"), files[i]);
+ _("closing %s failed"), ctl->files[i]);
}
}
}

int main(int argc, char **argv)
{
+ struct mcookie_control ctl;
size_t i;
- struct MD5Context ctx;
unsigned char digest[MD5LENGTH];
unsigned char buf[RAND_BYTES];
- char **files = NULL;
- int nfiles;
int c;
- int verbose = 0;

static const struct option longopts[] = {
{"file", required_argument, NULL, 'f'},
@@ -124,22 +128,21 @@ int main(int argc, char **argv)
textdomain(PACKAGE);
atexit(close_stdout);

- MD5Init(&ctx);
+ memset(&ctl, 0, sizeof(ctl));
+ MD5Init(&(ctl.ctx));

- if (2 < argc) {
- files = xmalloc(sizeof(char *) * argc);
- nfiles = 0;
- }
+ if (2 < argc)
+ ctl.files = xmalloc(sizeof(char *) * argc);

while ((c =
getopt_long(argc, argv, "f:vVh", longopts, NULL)) != -1)
switch (c) {
case 'v':
- verbose = 1;
+ ctl.verbose = 1;
break;
case 'f':
- files[nfiles] = optarg;
- nfiles++;
+ ctl.files[ctl.nfiles] = optarg;
+ ctl.nfiles++;
break;
case 'V':
printf(UTIL_LINUX_VERSION);
@@ -150,16 +153,16 @@ int main(int argc, char **argv)
usage(stderr);
}

- randomness_from_files(files, nfiles, &ctx, verbose);
- free(files);
+ randomness_from_files(&ctl);
+ free(ctl.files);

random_get_bytes(&buf, RAND_BYTES);
- MD5Update(&ctx, buf, RAND_BYTES);
- if (verbose)
+ MD5Update(&(ctl.ctx), buf, RAND_BYTES);
+ if (ctl.verbose)
fprintf(stderr,
_("Got %d bytes from %s\n"), RAND_BYTES, random_tell_source());

- MD5Final(digest, &ctx);
+ MD5Final(digest, &(ctl.ctx));
for (i = 0; i < MD5LENGTH; i++)
printf("%02x", digest[i]);
putchar('\n');
--
1.9.0