examples/blame.c

   1 /*
   2  * libgit2 "blame" example - shows how to use the blame API
   3  *
   4  * Written by the libgit2 contributors
   5  *
   6  * To the extent possible under law, the author(s) have dedicated all copyright
   7  * and related and neighboring rights to this software to the public domain
   8  * worldwide. This software is distributed without any warranty.
   9  *
  10  * You should have received a copy of the CC0 Public Domain Dedication along
  11  * with this software. If not, see
  12  * <http://creativecommons.org/publicdomain/zero/1.0/>.
  13  */
  14
  15 #include "common.h"
  16
  17 /**
  18  * This example demonstrates how to invoke the libgit2 blame API to roughly
  19  * simulate the output of `git blame` and a few of its command line arguments.
  20  */
  21
  22 static void usage(const char *msg, const char *arg);
  23
  24 int main(int argc, char *argv[])
  25 {
  26         int i, line, break_on_null_hunk;
  27         const char *path = NULL, *a;
  28         const char *rawdata, *commitspec=NULL, *bare_args[3] = {0};
  29         char spec[1024] = {0};
  30         git_repository *repo = NULL;
  31         git_revspec revspec = {0};
  32         git_blame_options opts = GIT_BLAME_OPTIONS_INIT;
  33         git_blame *blame = NULL;
  34         git_blob *blob;
  35
  36         git_threads_init();
  37
  38         if (argc < 2) usage(NULL, NULL);
  39
  40         for (i=1; i<argc; i++) {
  41                 a = argv[i];
  42
  43                 if (a[0] != '-') {
  44                         int i=0;
  45                         while (bare_args[i] && i < 3) ++i;
  46                         if (i >= 3)
  47                                 usage("Invalid argument set", NULL);
  48                         bare_args[i] = a;
  49                 }
  50                 else if (!strcmp(a, "--"))
  51                         continue;
  52                 else if (!strcasecmp(a, "-M"))
  53                         opts.flags |= GIT_BLAME_TRACK_COPIES_SAME_COMMIT_MOVES;
  54                 else if (!strcasecmp(a, "-C"))
  55                         opts.flags |= GIT_BLAME_TRACK_COPIES_SAME_COMMIT_COPIES;
  56                 else if (!strcasecmp(a, "-L")) {
  57                         i++; a = argv[i];
  58                         if (i >= argc) fatal("Not enough arguments to -L", NULL);
  59                         check_lg2(sscanf(a, "%d,%d", &opts.min_line, &opts.max_line)-2, "-L format error", NULL);
  60                 }
  61                 else {
  62                         /* commit range */
  63                         if (commitspec) fatal("Only one commit spec allowed", NULL);
  64                         commitspec = a;
  65                 }
  66         }
  67
  68         /* Handle the bare arguments */
  69         if (!bare_args[0]) usage("Please specify a path", NULL);
  70         path = bare_args[0];
  71         if (bare_args[1]) {
  72                 /* <commitspec> <path> */
  73                 path = bare_args[1];
  74                 commitspec = bare_args[0];
  75         }
  76         if (bare_args[2]) {
  77                 /* <oldcommit> <newcommit> <path> */
  78                 path = bare_args[2];
  79                 sprintf(spec, "%s..%s", bare_args[0], bare_args[1]);
  80                 commitspec = spec;
  81         }
  82
  83         /* Open the repo */
  84         check_lg2(git_repository_open_ext(&repo, ".", 0, NULL), "Couldn't open repository", NULL);
  85
  86         /* Parse the end points */
  87         if (commitspec) {
  88                 check_lg2(git_revparse(&revspec, repo, commitspec), "Couldn't parse commit spec", NULL);
  89                 if (revspec.flags & GIT_REVPARSE_SINGLE) {
  90                         git_oid_cpy(&opts.newest_commit, git_object_id(revspec.from));
  91                         git_object_free(revspec.from);
  92                 } else {
  93                         git_oid_cpy(&opts.oldest_commit, git_object_id(revspec.from));
  94                         git_oid_cpy(&opts.newest_commit, git_object_id(revspec.to));
  95                         git_object_free(revspec.from);
  96                         git_object_free(revspec.to);
  97                 }
  98         }
  99
 100         /* Run the blame */
 101         check_lg2(git_blame_file(&blame, repo, path, &opts), "Blame error", NULL);
 102
 103         /* Get the raw data for output */
 104         if (git_oid_iszero(&opts.newest_commit))
 105                 strcpy(spec, "HEAD");
 106         else
 107                 git_oid_tostr(spec, sizeof(spec), &opts.newest_commit);
 108         strcat(spec, ":");
 109         strcat(spec, path);
 110
 111         {
 112                 git_object *obj;
 113                 check_lg2(git_revparse_single(&obj, repo, spec), "Object lookup error", NULL);
 114                 check_lg2(git_blob_lookup(&blob, repo, git_object_id(obj)), "Blob lookup error", NULL);
 115                 git_object_free(obj);
 116         }
 117         rawdata = git_blob_rawcontent(blob);
 118
 119         /* Produce the output */
 120         line = 1;
 121         i = 0;
 122         break_on_null_hunk = 0;
 123         while (i < git_blob_rawsize(blob)) {
 124                 const char *eol = strchr(rawdata+i, '\n');
 125                 char oid[10] = {0};
 126                 const git_blame_hunk *hunk = git_blame_get_hunk_byline(blame, line);
 127
 128                 if (break_on_null_hunk && !hunk) break;
 129
 130                 if (hunk) {
 131                         break_on_null_hunk = 1;
 132                         char sig[128] = {0};
 133
 134                         git_oid_tostr(oid, 10, &hunk->final_commit_id);
 135                         snprintf(sig, 30, "%s <%s>", hunk->final_signature->name, hunk->final_signature->email);
 136
 137                         printf("%s ( %-30s %3d) %.*s\n",
 138                                         oid,
 139                                         sig,
 140                                         line,
 141                                         (int)(eol-rawdata-i),
 142                                         rawdata+i);
 143                 }
 144
 145                 i = eol - rawdata + 1;
 146                 line++;
 147         }
 148
 149         /* Cleanup */
 150         git_blob_free(blob);
 151         git_blame_free(blame);
 152         git_repository_free(repo);
 153         git_threads_shutdown();
 154 }
 155
 156 static void usage(const char *msg, const char *arg)
 157 {
 158         if (msg && arg)
 159                 fprintf(stderr, "%s: %s\n", msg, arg);
 160         else if (msg)
 161                 fprintf(stderr, "%s\n", msg);
 162         fprintf(stderr, "usage: blame [options] [<commit range>] <path>\n");
 163         fprintf(stderr, "\n");
 164         fprintf(stderr, "   <commit range>      example: `HEAD~10..HEAD`, or `1234abcd`\n");
 165         fprintf(stderr, "   -L <n,m>            process only line range n-m, counting from 1\n");
 166         fprintf(stderr, "   -M                  find line moves within and across files\n");
 167         fprintf(stderr, "   -C                  find line copies within and across files\n");
 168         fprintf(stderr, "\n");
 169         exit(1);
 170 }
 171