examples: create common lg2 executable

Inside of our networking example code, we have a git2 executable
that acts as an entry point to all the different network
examples. As such, it is kind of the same like the normal git(1)
executable in that it simply arbitrates to the respective
subcommands.

Let's extend this approach and merge all examples into a single
standalone lg2 executable. Instead of building an executable
for all the existing examples we have, we now bundle them all
inside of the lg2 one and let them be callable via subcommands.

In the process, we can get rid of duplicated library
initialization, deinitialization and repository discovery code.
Instead of having each subcommand handle these on its own, we
simply do it inside of the single main function now.

1 files changed, 66 insertions, 0 deletions

diff --git a/examples/show-index.c b/examples/show-index.c
new file mode 100644
index 000000000..6acadbeb6
--- /dev/null
+++ b/examples/show-index.c
@@ -0,0 +1,66 @@
+/*
+ * libgit2 "showindex" example - shows how to extract data from the index
+ *
+ * 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"
+
+int lg2_show_index(git_repository *repo, int argc, char** argv)
+{
+	git_index *index;
+	unsigned int i, ecount;
+	char *dir = ".";
+	size_t dirlen;
+	char out[GIT_OID_HEXSZ+1];
+	out[GIT_OID_HEXSZ] = '\0';
+
+	if (argc > 2)
+		fatal("usage: showindex [<repo-dir>]", NULL);
+	if (argc > 1)
+		dir = argv[1];
+
+	dirlen = strlen(dir);
+	if (dirlen > 5 && strcmp(dir + dirlen - 5, "index") == 0) {
+		check_lg2(git_index_open(&index, dir), "could not open index", dir);
+	} else {
+		check_lg2(git_repository_open_ext(&repo, dir, 0, NULL), "could not open repository", dir);
+		check_lg2(git_repository_index(&index, repo), "could not open repository index", NULL);
+		git_repository_free(repo);
+	}
+
+	git_index_read(index, 0);
+
+	ecount = git_index_entrycount(index);
+	if (!ecount)
+		printf("Empty index\n");
+
+	for (i = 0; i < ecount; ++i) {
+		const git_index_entry *e = git_index_get_byindex(index, i);
+
+		git_oid_fmt(out, &e->id);
+
+		printf("File Path: %s\n", e->path);
+		printf("    Stage: %d\n", git_index_entry_stage(e));
+		printf(" Blob SHA: %s\n", out);
+		printf("File Mode: %07o\n", e->mode);
+		printf("File Size: %d bytes\n", (int)e->file_size);
+		printf("Dev/Inode: %d/%d\n", (int)e->dev, (int)e->ino);
+		printf("  UID/GID: %d/%d\n", (int)e->uid, (int)e->gid);
+		printf("    ctime: %d\n", (int)e->ctime.seconds);
+		printf("    mtime: %d\n", (int)e->mtime.seconds);
+		printf("\n");
+	}
+
+	git_index_free(index);
+
+	return 0;
+}