mcookie: use control structure, and fix usage()

[thirdparty/util-linux.git] / misc-utils / mcookie.c

diff --git a/misc-utils/mcookie.c b/misc-utils/mcookie.c
index 3f94034053f21acc67b77e2a4e860ee45ba605ea..494c1cf89209e0276870c2aca276f1c9ac06ebad 100644 (file)
--- a/misc-utils/mcookie.c
+++ b/misc-utils/mcookie.c
@@ -38,78 +38,87 @@ enum {
        RAND_BYTES = 128
 };
 
+struct mcookie_control {
+       struct  MD5Context ctx;
+       char    **files;
+       size_t  nfiles;
+
+       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, int fd)
 {
        size_t count = 0;
        ssize_t r;
        unsigned char buf[BUFFERSIZE];
 
        while ((r = read(fd, buf, sizeof(buf))) > 0) {
-               MD5Update(ctx, buf, r);
+               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(USAGE_HEADER, 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_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;
-       size_t count = 0;
+       size_t i;
+
+       for (i = 0; i < ctl->nfiles; i++) {
+               const char *fname = ctl->files[i];
+               size_t count;
+               int fd;
 
-       for (i = 0; i < nfiles; i++) {
-               if (files[i][0] == '-' && !files[i][1])
+               if (*fname == '-' && !*(fname + 1))
                        fd = STDIN_FILENO;
                else
-                       fd = open(files[i], O_RDONLY);
+                       fd = open(fname, O_RDONLY);
 
                if (fd < 0) {
-                       warn(_("cannot open %s"), files[i]);
+                       warn(_("cannot open %s"), fname);
                } else {
-                       count = hash_file(ctx, fd);
-                       if (verbose)
+                       count = hash_file(ctl, fd);
+                       if (ctl->verbose)
                                fprintf(stderr,
                                        P_("Got %zu byte from %s\n",
                                           "Got %zu bytes from %s\n", count),
-                                       count, files[i]);
+                                       count, fname);
 
                        if (fd != STDIN_FILENO)
                                if (close(fd))
                                        err(EXIT_FAILURE,
-                                           _("closing %s failed"), files[i]);
+                                           _("closing %s failed"), fname);
                }
        }
 }
 
 int main(int argc, char **argv)
 {
+       struct mcookie_control ctl = { .verbose = 0 };
        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 +133,16 @@ int main(int argc, char **argv)
        textdomain(PACKAGE);
        atexit(close_stdout);
 
-       MD5Init(&ctx);
+       if (2 < argc)
+               ctl.files = xmalloc(sizeof(char *) * argc);
 
-       if (2 < argc) {
-               files = xmalloc(sizeof(char *) * argc);
-               nfiles = 0;
-       }
-
-       while ((c =
-               getopt_long(argc, argv, "f:vVh", longopts, NULL)) != -1)
+       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;
                        break;
                case 'V':
                        printf(UTIL_LINUX_VERSION);
@@ -149,17 +152,18 @@ int main(int argc, char **argv)
                default:
                        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)
-               fprintf(stderr,
-                       _("Got %d bytes from %s\n"), RAND_BYTES, random_tell_source());
+       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');