+/*
+ * Tool for decoding compact index values for testing.
+ * Copyright © 2012 Nick Bowler
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <getopt.h>
+
+#include <upkg.h>
+
+#define PROGNAME "decodeindex"
+static const char *progname = PROGNAME;
+static const unsigned char sopts[] = "VH";
+static const struct option lopts[] = {
+ { "version", 0, NULL, 'V' },
+ { "help", 0, NULL, 'H' },
+ { 0 }
+};
+
+/*
+ * Decode a hexadecimal string into a sequence of bytes. If there are an
+ * odd number of nibbles, treat the first character as the least significant
+ * nibble of the first byte. The result is written to the buffer specified by
+ * buf. At most n bytes are written to the buffer.
+ *
+ * Returns the number of bytes that would be written provided that n was large
+ * enough, or (size_t)-1 if the input is not valid.
+ */
+static size_t decode_hex(const char *hex, unsigned char *buf, size_t n)
+{
+ size_t len, count = 0;
+ char tmp[] = "00";
+
+ for (len = 0; hex[len]; len++) {
+ if (!isxdigit(hex[len]))
+ return -1;
+ }
+
+ if (!len)
+ return 0;
+
+ switch (len % 2) {
+ while (len > 0) {
+ case 0: tmp[0] = *hex++; len--;
+ case 1: tmp[1] = *hex++; len--;
+
+ if (count < n)
+ buf[count] = strtoul(tmp, NULL, 16);
+ count++;
+ }
+ }
+
+ return count;
+}
+
+static void print_usage(FILE *f)
+{
+ fprintf(f, "Usage: %s [options] index [index ...]\n", progname);
+}
+
+static void print_version(void)
+{
+ printf("%s (%s) %s\n", PROGNAME, PACKAGE_NAME, PACKAGE_VERSION);
+ puts("Copyright (C) 2012 Nick Bowler.");
+ puts("License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.");
+ puts("This is free software: you are free to change and redistribute it.");
+ puts("There is NO WARRANTY, to the extent permitted by law.");
+}
+
+static void print_bytes(FILE *f, int indent, void *buf, size_t n)
+{
+ fprintf(f, "%*s", indent, "");
+ for (size_t i = 0; i < n; i++)
+ fprintf(f, "%*s%.2hhx", i != 0, "", ((unsigned char *)buf)[i]);
+ putc('\n', f);
+}
+
+static int print_index(const char *hex)
+{
+ unsigned char buf[32];
+ long index = 0;
+ size_t n, rc;
+ int ret = -1;
+
+ n = decode_hex(hex, buf, sizeof buf);
+ if (n == -1) {
+ fprintf(stderr, "%s: invalid hex sequence: %s\n",
+ progname, hex);
+ goto out;
+ } else if (n == 0) {
+ fprintf(stderr, "%s: empty argument\n", progname);
+ goto out;
+ } else if (n > sizeof buf) {
+ fprintf(stderr, "%s: hex sequence too long: %s\n",
+ progname, hex);
+ goto out;
+ }
+
+ rc = upkg_decode_index(&index, buf, n);
+ if (rc == 0) {
+ fprintf(stderr, "%s: invalid index encoding:\n", progname);
+ print_bytes(stderr, 4, buf, n);
+ goto out;
+ } else if (rc < n) {
+ fprintf(stderr, "%s: trailing bytes in argument:\n", progname);
+ print_bytes(stderr, 4, buf+rc, n-rc);
+ /* Non-fatal */
+ }
+
+ ret = 0;
+out:
+ printf("%ld\n", index);
+ return ret;
+}
+
+int main(int argc, char **argv)
+{
+ int opt, ret = EXIT_SUCCESS;
+
+ if (argc > 0)
+ progname = argv[0];
+
+ while ((opt = getopt_long(argc, argv, sopts, lopts, NULL)) != -1) {
+ switch (opt) {
+ case 'V':
+ print_version();
+ return EXIT_SUCCESS;
+ case 'H':
+ print_usage(stdout);
+ return EXIT_SUCCESS;
+ default:
+ print_usage(stderr);
+ return EXIT_FAILURE;
+ }
+ }
+
+ if (!argv[optind]) {
+ print_usage(stderr);
+ return EXIT_FAILURE;
+ }
+
+ for (int i = optind; i < argc; i++) {
+ if (print_index(argv[i]) != 0) {
+ ret = EXIT_FAILURE;
+ }
+ }
+
+ return ret;
+}