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         int F;
  35 };
  36 static void parse_opts(struct opts *o, int argc, char *argv[]);
  37
  38 int main(int argc, char *argv[])
  39 {
  40         int i, line, break_on_null_hunk;
  41         char spec[1024] = {0};
  42         struct opts o = {0};
  43         const char *rawdata;
  44         git_repository *repo = NULL;
  45         git_revspec revspec = {0};
  46         git_blame_options blameopts = GIT_BLAME_OPTIONS_INIT;
  47         git_blame *blame = NULL;
  48         git_blob *blob;
  49         git_object *obj;
  50
  51         git_threads_init();
  52
  53         parse_opts(&o, argc, argv);
  54         if (o.M) blameopts.flags |= GIT_BLAME_TRACK_COPIES_SAME_COMMIT_MOVES;
  55         if (o.C) blameopts.flags |= GIT_BLAME_TRACK_COPIES_SAME_COMMIT_COPIES;
  56         if (o.F) blameopts.flags |= GIT_BLAME_FIRST_PARENT;
  57
  58         /** Open the repository. */
  59         check_lg2(git_repository_open_ext(&repo, ".", 0, NULL), "Couldn't open repository", NULL);
  60
  61         /**
  62          * The commit range comes in "commitish" form. Use the rev-parse API to
  63          * nail down the end points.
  64          */
  65         if (o.commitspec) {
  66                 check_lg2(git_revparse(&revspec, repo, o.commitspec), "Couldn't parse commit spec", NULL);
  67                 if (revspec.flags & GIT_REVPARSE_SINGLE) {
  68                         git_oid_cpy(&blameopts.newest_commit, git_object_id(revspec.from));
  69                         git_object_free(revspec.from);
  70                 } else {
  71                         git_oid_cpy(&blameopts.oldest_commit, git_object_id(revspec.from));
  72                         git_oid_cpy(&blameopts.newest_commit, git_object_id(revspec.to));
  73                         git_object_free(revspec.from);
  74                         git_object_free(revspec.to);
  75                 }
  76         }
  77
  78         /** Run the blame. */
  79         check_lg2(git_blame_file(&blame, repo, o.path, &blameopts), "Blame error", NULL);
  80
  81         /**
  82          * Get the raw data inside the blob for output. We use the
  83          * `commitish:path/to/file.txt` format to find it.
  84          */
  85         if (git_oid_iszero(&blameopts.newest_commit))
  86                 strcpy(spec, "HEAD");
  87         else
  88                 git_oid_tostr(spec, sizeof(spec), &blameopts.newest_commit);
  89         strcat(spec, ":");
  90         strcat(spec, o.path);
  91
  92         check_lg2(git_revparse_single(&obj, repo, spec), "Object lookup error", NULL);
  93         check_lg2(git_blob_lookup(&blob, repo, git_object_id(obj)), "Blob lookup error", NULL);
  94         git_object_free(obj);
  95
  96         rawdata = git_blob_rawcontent(blob);
  97
  98         /** Produce the output. */
  99         line = 1;
 100         i = 0;
 101         break_on_null_hunk = 0;
 102         while (i < git_blob_rawsize(blob)) {
 103                 const char *eol = strchr(rawdata+i, '\n');
 104                 char oid[10] = {0};
 105                 const git_blame_hunk *hunk = git_blame_get_hunk_byline(blame, line);
 106
 107                 if (break_on_null_hunk && !hunk) break;
 108
 109                 if (hunk) {
 110                         char sig[128] = {0};
 111                         break_on_null_hunk = 1;
 112
 113
 114                         git_oid_tostr(oid, 10, &hunk->final_commit_id);
 115                         snprintf(sig, 30, "%s <%s>", hunk->final_signature->name, hunk->final_signature->email);
 116
 117                         printf("%s ( %-30s %3d) %.*s\n",
 118                                         oid,
 119                                         sig,
 120                                         line,
 121                                         (int)(eol-rawdata-i),
 122                                         rawdata+i);
 123                 }
 124
 125                 i = (int)(eol - rawdata + 1);
 126                 line++;
 127         }
 128
 129         /** Cleanup. */
 130         git_blob_free(blob);
 131         git_blame_free(blame);
 132         git_repository_free(repo);
 133
 134         git_threads_shutdown();
 135
 136         return 0;
 137 }
 138
 139 /** Tell the user how to make this thing work. */
 140 static void usage(const char *msg, const char *arg)
 141 {
 142         if (msg && arg)
 143                 fprintf(stderr, "%s: %s\n", msg, arg);
 144         else if (msg)
 145                 fprintf(stderr, "%s\n", msg);
 146         fprintf(stderr, "usage: blame [options] [<commit range>] <path>\n");
 147         fprintf(stderr, "\n");
 148         fprintf(stderr, "   <commit range>      example: `HEAD~10..HEAD`, or `1234abcd`\n");
 149         fprintf(stderr, "   -L <n,m>            process only line range n-m, counting from 1\n");
 150         fprintf(stderr, "   -M                  find line moves within and across files\n");
 151         fprintf(stderr, "   -C                  find line copies within and across files\n");
 152         fprintf(stderr, "   -F                  follow only the first parent commits\n");
 153         fprintf(stderr, "\n");
 154         exit(1);
 155 }
 156
 157 /** Parse the arguments. */
 158 static void parse_opts(struct opts *o, int argc, char *argv[])
 159 {
 160         int i;
 161         char *bare_args[3] = {0};
 162
 163         if (argc < 2) usage(NULL, NULL);
 164
 165         for (i=1; i<argc; i++) {
 166                 char *a = argv[i];
 167
 168                 if (a[0] != '-') {
 169                         int i=0;
 170                         while (bare_args[i] && i < 3) ++i;
 171                         if (i >= 3)
 172                                 usage("Invalid argument set", NULL);
 173                         bare_args[i] = a;
 174                 }
 175                 else if (!strcmp(a, "--"))
 176                         continue;
 177                 else if (!strcasecmp(a, "-M"))
 178                         o->M = 1;
 179                 else if (!strcasecmp(a, "-C"))
 180                         o->C = 1;
 181                 else if (!strcasecmp(a, "-F"))
 182                         o->F = 1;
 183                 else if (!strcasecmp(a, "-L")) {
 184                         i++; a = argv[i];
 185                         if (i >= argc) fatal("Not enough arguments to -L", NULL);
 186                         check_lg2(sscanf(a, "%d,%d", &o->start_line, &o->end_line)-2, "-L format error", NULL);
 187                 }
 188                 else {
 189                         /* commit range */
 190                         if (o->commitspec) fatal("Only one commit spec allowed", NULL);
 191                         o->commitspec = a;
 192                 }
 193         }
 194
 195         /* Handle the bare arguments */
 196         if (!bare_args[0]) usage("Please specify a path", NULL);
 197         o->path = bare_args[0];
 198         if (bare_args[1]) {
 199                 /* <commitspec> <path> */
 200                 o->path = bare_args[1];
 201                 o->commitspec = bare_args[0];
 202         }
 203         if (bare_args[2]) {
 204                 /* <oldcommit> <newcommit> <path> */
 205                 char spec[128] = {0};
 206                 o->path = bare_args[2];
 207                 sprintf(spec, "%s..%s", bare_args[0], bare_args[1]);
 208                 o->commitspec = spec;
 209         }
 210 }