Add support for some basic options in plocate-build; specifically, block size.

This also means it will stop segfaulting if no options are given.

diff --git a/plocate-build.cpp b/plocate-build.cpp
index 023aedb53339da12b0e5487f662d5193fca6943f..a077ac1944358ecee7e622e9846982d7ba39c064 100644 (file)
--- a/plocate-build.cpp
+++ b/plocate-build.cpp
@@ -5,6 +5,7 @@
 #include <assert.h>
 #include <chrono>
 #include <iosfwd>
+#include <getopt.h>
 #include <math.h>
 #include <memory>
 #include <stdint.h>
@@ -494,8 +495,66 @@ void do_build(const char *infile, const char *outfile, int block_size)
        dprintf("\n");
 }
 
+void usage()
+{
+       printf(
+               "Usage: plocate-build MLOCATE_DB PLOCATE_DB\n"
+               "\n"
+               "Generate plocate index from mlocate.db, typically /var/lib/mlocate/mlocate.db.\n"
+               "Normally, the destination should be /var/lib/mlocate/plocate.db.\n"
+               "\n"
+               "  -b, --block-size SIZE  number of filenames to store in each block (default 32)\n"
+               "      --help             print this help\n"
+               "      --version          print version information\n");
+}
+
+void version()
+{
+       printf("plocate-build %s\n", PLOCATE_VERSION);
+       printf("Copyright 2020 Steinar H. Gunderson\n");
+       printf("License GPLv2+: GNU GPL version 2 or later <https://gnu.org/licenses/gpl.html>.\n");
+       printf("This is free software: you are free to change and redistribute it.\n");
+       printf("There is NO WARRANTY, to the extent permitted by law.\n");
+}
+
 int main(int argc, char **argv)
 {
-       do_build(argv[1], argv[2], 32);
+       static const struct option long_options[] = {
+               { "block-size", required_argument, 0, 'b' },
+               { "help", no_argument, 0, 'h' },
+               { "version", no_argument, 0, 'V' },
+               { 0, 0, 0, 0 }
+       };
+
+       int block_size = 32;
+
+       setlocale(LC_ALL, "");
+       for (;;) {
+               int option_index = 0;
+               int c = getopt_long(argc, argv, "b:hV", long_options, &option_index);
+               if (c == -1) {
+                       break;
+               }
+               switch (c) {
+               case 'b':
+                       block_size = atoi(optarg);
+                       break;
+               case 'h':
+                       usage();
+                       exit(0);
+               case 'v':
+                       version();
+                       exit(0);
+               default:
+                       exit(1);
+               }
+       }
+
+       if (argc - optind != 2) {
+               usage();
+               exit(1);
+       }
+
+       do_build(argv[optind], argv[optind + 1], block_size);
        exit(EXIT_SUCCESS);
 }