1 files changed, 239 insertions, 0 deletions
diff --git a/examples/cat-file.c b/examples/cat-file.c
new file mode 100644
index 0000000..741edb4
--- /dev/null
+++ b/examples/cat-file.c
@@ -0,0 +1,239 @@
+/*
+ * libgit2 "cat-file" example - shows how to print data from the ODB
+ *
+ * Written by the libgit2 contributors
+ *
+ * To the extent possible under law, the author(s) have dedicated all copyright
+ * and related and neighboring rights to this software to the public domain
+ * worldwide. This software is distributed without any warranty.
+ *
+ * You should have received a copy of the CC0 Public Domain Dedication along
+ * with this software. If not, see
+ * <http://creativecommons.org/publicdomain/zero/1.0/>.
+ */
+
+#include "common.h"
+
+static void print_signature(const char *header, const git_signature *sig)
+{
+	char sign;
+	int offset, hours, minutes;
+
+	if (!sig)
+		return;
+
+	offset = sig->when.offset;
+	if (offset < 0) {
+		sign = '-';
+		offset = -offset;
+	} else {
+		sign = '+';
+	}
+
+	hours   = offset / 60;
+	minutes = offset % 60;
+
+	printf("%s %s <%s> %ld %c%02d%02d\n",
+		   header, sig->name, sig->email, (long)sig->when.time,
+		   sign, hours, minutes);
+}
+
+/** Printing out a blob is simple, get the contents and print */
+static void show_blob(const git_blob *blob)
+{
+	/* ? Does this need crlf filtering? */
+	fwrite(git_blob_rawcontent(blob), (size_t)git_blob_rawsize(blob), 1, stdout);
+}
+
+/** Show each entry with its type, id and attributes */
+static void show_tree(const git_tree *tree)
+{
+	size_t i, max_i = (int)git_tree_entrycount(tree);
+	char oidstr[GIT_OID_SHA1_HEXSIZE + 1];
+	const git_tree_entry *te;
+
+	for (i = 0; i < max_i; ++i) {
+		te = git_tree_entry_byindex(tree, i);
+
+		git_oid_tostr(oidstr, sizeof(oidstr), git_tree_entry_id(te));
+
+		printf("%06o %s %s\t%s\n",
+			git_tree_entry_filemode(te),
+			git_object_type2string(git_tree_entry_type(te)),
+			oidstr, git_tree_entry_name(te));
+	}
+}
+
+/**
+ * Commits and tags have a few interesting fields in their header.
+ */
+static void show_commit(const git_commit *commit)
+{
+	unsigned int i, max_i;
+	char oidstr[GIT_OID_SHA1_HEXSIZE + 1];
+
+	git_oid_tostr(oidstr, sizeof(oidstr), git_commit_tree_id(commit));
+	printf("tree %s\n", oidstr);
+
+	max_i = (unsigned int)git_commit_parentcount(commit);
+	for (i = 0; i < max_i; ++i) {
+		git_oid_tostr(oidstr, sizeof(oidstr), git_commit_parent_id(commit, i));
+		printf("parent %s\n", oidstr);
+	}
+
+	print_signature("author", git_commit_author(commit));
+	print_signature("committer", git_commit_committer(commit));
+
+	if (git_commit_message(commit))
+		printf("\n%s\n", git_commit_message(commit));
+}
+
+static void show_tag(const git_tag *tag)
+{
+	char oidstr[GIT_OID_SHA1_HEXSIZE + 1];
+
+	git_oid_tostr(oidstr, sizeof(oidstr), git_tag_target_id(tag));;
+	printf("object %s\n", oidstr);
+	printf("type %s\n", git_object_type2string(git_tag_target_type(tag)));
+	printf("tag %s\n", git_tag_name(tag));
+	print_signature("tagger", git_tag_tagger(tag));
+
+	if (git_tag_message(tag))
+		printf("\n%s\n", git_tag_message(tag));
+}
+
+typedef enum {
+	SHOW_TYPE = 1,
+	SHOW_SIZE = 2,
+	SHOW_NONE = 3,
+	SHOW_PRETTY = 4
+} catfile_mode;
+
+/* Forward declarations for option-parsing helper */
+struct catfile_options {
+	const char *dir;
+	const char *rev;
+	catfile_mode action;
+	int verbose;
+};
+
+static void parse_opts(struct catfile_options *o, int argc, char *argv[]);
+
+
+/** Entry point for this command */
+int lg2_cat_file(git_repository *repo, int argc, char *argv[])
+{
+	struct catfile_options o = { ".", NULL, 0, 0 };
+	git_object *obj = NULL;
+	char oidstr[GIT_OID_SHA1_HEXSIZE + 1];
+
+	parse_opts(&o, argc, argv);
+
+	check_lg2(git_revparse_single(&obj, repo, o.rev),
+			"Could not resolve", o.rev);
+
+	if (o.verbose) {
+		char oidstr[GIT_OID_SHA1_HEXSIZE + 1];
+		git_oid_tostr(oidstr, sizeof(oidstr), git_object_id(obj));
+
+		printf("%s %s\n--\n",
+			git_object_type2string(git_object_type(obj)), oidstr);
+	}
+
+	switch (o.action) {
+	case SHOW_TYPE:
+		printf("%s\n", git_object_type2string(git_object_type(obj)));
+		break;
+	case SHOW_SIZE: {
+		git_odb *odb;
+		git_odb_object *odbobj;
+
+		check_lg2(git_repository_odb(&odb, repo), "Could not open ODB", NULL);
+		check_lg2(git_odb_read(&odbobj, odb, git_object_id(obj)),
+			"Could not find obj", NULL);
+
+		printf("%ld\n", (long)git_odb_object_size(odbobj));
+
+		git_odb_object_free(odbobj);
+		git_odb_free(odb);
+		}
+		break;
+	case SHOW_NONE:
+		/* just want return result */
+		break;
+	case SHOW_PRETTY:
+
+		switch (git_object_type(obj)) {
+		case GIT_OBJECT_BLOB:
+			show_blob((const git_blob *)obj);
+			break;
+		case GIT_OBJECT_COMMIT:
+			show_commit((const git_commit *)obj);
+			break;
+		case GIT_OBJECT_TREE:
+			show_tree((const git_tree *)obj);
+			break;
+		case GIT_OBJECT_TAG:
+			show_tag((const git_tag *)obj);
+			break;
+		default:
+			printf("unknown %s\n", oidstr);
+			break;
+		}
+		break;
+	}
+
+	git_object_free(obj);
+
+	return 0;
+}
+
+/** Print out usage information */
+static void usage(const char *message, const char *arg)
+{
+	if (message && arg)
+		fprintf(stderr, "%s: %s\n", message, arg);
+	else if (message)
+		fprintf(stderr, "%s\n", message);
+	fprintf(stderr,
+			"usage: cat-file (-t | -s | -e | -p) [-v] [-q] "
+			"[-h|--help] [--git-dir=<dir>] <object>\n");
+	exit(1);
+}
+
+/** Parse the command-line options taken from git */
+static void parse_opts(struct catfile_options *o, int argc, char *argv[])
+{
+	struct args_info args = ARGS_INFO_INIT;
+
+	for (args.pos = 1; args.pos < argc; ++args.pos) {
+		char *a = argv[args.pos];
+
+		if (a[0] != '-') {
+			if (o->rev != NULL)
+				usage("Only one rev should be provided", NULL);
+			else
+				o->rev = a;
+		}
+		else if (!strcmp(a, "-t"))
+			o->action = SHOW_TYPE;
+		else if (!strcmp(a, "-s"))
+			o->action = SHOW_SIZE;
+		else if (!strcmp(a, "-e"))
+			o->action = SHOW_NONE;
+		else if (!strcmp(a, "-p"))
+			o->action = SHOW_PRETTY;
+		else if (!strcmp(a, "-q"))
+			o->verbose = 0;
+		else if (!strcmp(a, "-v"))
+			o->verbose = 1;
+		else if (!strcmp(a, "--help") || !strcmp(a, "-h"))
+			usage(NULL, NULL);
+		else if (!match_str_arg(&o->dir, &args, "--git-dir"))
+			usage("Unknown option", a);
+	}
+
+	if (!o->action || !o->rev)
+		usage(NULL, NULL);
+
+}