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 #ifdef _MSC_VER
  18 #define snprintf sprintf_s
  19 #define strcasecmp strcmpi
  20 #endif
  21
  22 /**
  23  * This example demonstrates how to invoke the libgit2 blame API to roughly
  24  * simulate the output of `git blame` and a few of its command line arguments.
  25  */
  26
  27 struct opts {
  28         char *path;
  29         char *commitspec;
  30         int C;
  31         int M;
  32         int start_line;
  33         int end_line;
  34 };
  35 static void parse_opts(struct opts *o, int argc, char *argv[]);
  36
  37 int main(int argc, char *argv[])
  38 {
  39         int i, line, break_on_null_hunk;
  40         char spec[1024] = {0};
  41         struct opts o = {0};
  42         const char *rawdata;
  43         git_repository *repo = NULL;
  44         git_revspec revspec = {0};
  45         git_blame_options blameopts = GIT_BLAME_OPTIONS_INIT;
  46         git_blame *blame = NULL;
  47         git_blob *blob;
  48         git_object *obj;
  49
  50         git_threads_init();
  51
  52         parse_opts(&o, argc, argv);
  53         if (o.M) blameopts.flags |= GIT_BLAME_TRACK_COPIES_SAME_COMMIT_MOVES;
  54         if (o.C) blameopts.flags |= GIT_BLAME_TRACK_COPIES_SAME_COMMIT_COPIES;
  55
  56         /** Open the repository. */
  57         check_lg2(git_repository_open_ext(&repo, ".", 0, NULL), "Couldn't open repository", NULL);
  58
  59         /**
  60          * The commit range comes in "commitish" form. Use the rev-parse API to
  61          * nail down the end points.
  62          */
  63         if (o.commitspec) {
  64                 check_lg2(git_revparse(&revspec, repo, o.commitspec), "Couldn't parse commit spec", NULL);
  65                 if (revspec.flags & GIT_REVPARSE_SINGLE) {
  66                         git_oid_cpy(&blameopts.newest_commit, git_object_id(revspec.from));
  67                         git_object_free(revspec.from);
  68                 } else {
  69                         git_oid_cpy(&blameopts.oldest_commit, git_object_id(revspec.from));
  70                         git_oid_cpy(&blameopts.newest_commit, git_object_id(revspec.to));
  71                         git_object_free(revspec.from);
  72                         git_object_free(revspec.to);
  73                 }
  74         }
  75
  76         /** Run the blame. */
  77         check_lg2(git_blame_file(&blame, repo, o.path, &blameopts), "Blame error", NULL);
  78
  79         /**
  80          * Get the raw data inside the blob for output. We use the
  81          * `commitish:path/to/file.txt` format to find it.
  82          */
  83         if (git_oid_iszero(&blameopts.newest_commit))
  84                 strcpy(spec, "HEAD");
  85         else
  86                 git_oid_tostr(spec, sizeof(spec), &blameopts.newest_commit);
  87         strcat(spec, ":");
  88         strcat(spec, o.path);
  89
  90         check_lg2(git_revparse_single(&obj, repo, spec), "Object lookup error", NULL);
  91         check_lg2(git_blob_lookup(&blob, repo, git_object_id(obj)), "Blob lookup error", NULL);
  92         git_object_free(obj);
  93
  94         rawdata = git_blob_rawcontent(blob);
  95
  96         /** Produce the output. */
  97         line = 1;
  98         i = 0;
  99         break_on_null_hunk = 0;
 100         while (i < git_blob_rawsize(blob)) {
 101                 const char *eol = strchr(rawdata+i, '\n');
 102                 char oid[10] = {0};
 103                 const git_blame_hunk *hunk = git_blame_get_hunk_byline(blame, line);
 104
 105                 if (break_on_null_hunk && !hunk) break;
 106
 107                 if (hunk) {
 108                         break_on_null_hunk = 1;
 109                         char sig[128] = {0};
 110
 111                         git_oid_tostr(oid, 10, &hunk->final_commit_id);
 112                         snprintf(sig, 30, "%s <%s>", hunk->final_signature->name, hunk->final_signature->email);
 113
 114                         printf("%s ( %-30s %3d) %.*s\n",
 115                                         oid,
 116                                         sig,
 117                                         line,
 118                                         (int)(eol-rawdata-i),
 119                                         rawdata+i);
 120                 }
 121
 122                 i = (int)(eol - rawdata + 1);
 123                 line++;
 124         }
 125
 126         /** Cleanup. */
 127         git_blob_free(blob);
 128         git_blame_free(blame);
 129         git_repository_free(repo);
 130
 131         git_threads_shutdown();
 132
 133         return 0;
 134 }
 135
 136 /** Tell the user how to make this thing work. */
 137 static void usage(const char *msg, const char *arg)
 138 {
 139         if (msg && arg)
 140                 fprintf(stderr, "%s: %s\n", msg, arg);
 141         else if (msg)
 142                 fprintf(stderr, "%s\n", msg);
 143         fprintf(stderr, "usage: blame [options] [<commit range>] <path>\n");
 144         fprintf(stderr, "\n");
 145         fprintf(stderr, "   <commit range>      example: `HEAD~10..HEAD`, or `1234abcd`\n");
 146         fprintf(stderr, "   -L <n,m>            process only line range n-m, counting from 1\n");
 147         fprintf(stderr, "   -M                  find line moves within and across files\n");
 148         fprintf(stderr, "   -C                  find line copies within and across files\n");
 149         fprintf(stderr, "\n");
 150         exit(1);
 151 }
 152
 153 /** Parse the arguments. */
 154 static void parse_opts(struct opts *o, int argc, char *argv[])
 155 {
 156         int i;
 157         char *bare_args[3] = {0};
 158
 159         if (argc < 2) usage(NULL, NULL);
 160
 161         for (i=1; i<argc; i++) {
 162                 char *a = argv[i];
 163
 164                 if (a[0] != '-') {
 165                         int i=0;
 166                         while (bare_args[i] && i < 3) ++i;
 167                         if (i >= 3)
 168                                 usage("Invalid argument set", NULL);
 169                         bare_args[i] = a;
 170                 }
 171                 else if (!strcmp(a, "--"))
 172                         continue;
 173                 else if (!strcasecmp(a, "-M"))
 174                         o->M = 1;
 175                 else if (!strcasecmp(a, "-C"))
 176                         o->C = 1;
 177                 else if (!strcasecmp(a, "-L")) {
 178                         i++; a = argv[i];
 179                         if (i >= argc) fatal("Not enough arguments to -L", NULL);
 180                         check_lg2(sscanf(a, "%d,%d", &o->start_line, &o->end_line)-2, "-L format error", NULL);
 181                 }
 182                 else {
 183                         /* commit range */
 184                         if (o->commitspec) fatal("Only one commit spec allowed", NULL);
 185                         o->commitspec = a;
 186                 }
 187         }
 188
 189         /* Handle the bare arguments */
 190         if (!bare_args[0]) usage("Please specify a path", NULL);
 191         o->path = bare_args[0];
 192         if (bare_args[1]) {
 193                 /* <commitspec> <path> */
 194                 o->path = bare_args[1];
 195                 o->commitspec = bare_args[0];
 196         }
 197         if (bare_args[2]) {
 198                 /* <oldcommit> <newcommit> <path> */
 199                 char spec[128] = {0};
 200                 o->path = bare_args[2];
 201                 sprintf(spec, "%s..%s", bare_args[0], bare_args[1]);
 202                 o->commitspec = spec;
 203         }
 204 }