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authorEdward Thomson <ethomson@edwardthomson.com>2021-11-28 10:32:03 -0500
committerEdward Thomson <ethomson@edwardthomson.com>2022-02-26 14:43:48 -0500
commitb877122750aa0435bab701825378754783d09485 (patch)
tree765d8c6511bdf2018c091840c8e6cb8cb5a1e85e
parentf8e7d8fdde563df6c9351296b6330bb8cc859066 (diff)
downloadlibgit2-b877122750aa0435bab701825378754783d09485.tar.gz
cli: add `cat-file` command
Introduce a simple command that emulates `git cat-file`.
-rw-r--r--src/cli/cmd.h1
-rw-r--r--src/cli/cmd_cat_file.c204
-rw-r--r--src/cli/main.c3
3 files changed, 207 insertions, 1 deletions
diff --git a/src/cli/cmd.h b/src/cli/cmd.h
index 816614efc..cc1743ed2 100644
--- a/src/cli/cmd.h
+++ b/src/cli/cmd.h
@@ -25,6 +25,7 @@ extern const cli_cmd_spec cli_cmds[];
extern const cli_cmd_spec *cli_cmd_spec_byname(const char *name);
/* Commands */
+extern int cmd_cat_file(int argc, char **argv);
extern int cmd_help(int argc, char **argv);
#endif /* CLI_cmd_h__ */
diff --git a/src/cli/cmd_cat_file.c b/src/cli/cmd_cat_file.c
new file mode 100644
index 000000000..fb53a722b
--- /dev/null
+++ b/src/cli/cmd_cat_file.c
@@ -0,0 +1,204 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include <git2.h>
+#include "cli.h"
+#include "cmd.h"
+
+#define COMMAND_NAME "cat-file"
+
+typedef enum {
+ DISPLAY_CONTENT = 0,
+ DISPLAY_EXISTS,
+ DISPLAY_PRETTY,
+ DISPLAY_SIZE,
+ DISPLAY_TYPE
+} display_t;
+
+static int show_help;
+static int display = DISPLAY_CONTENT;
+static char *type_name, *object_spec;
+
+static const cli_opt_spec opts[] = {
+ { CLI_OPT_TYPE_SWITCH, "help", 0, &show_help, 1,
+ CLI_OPT_USAGE_HIDDEN | CLI_OPT_USAGE_STOP_PARSING, NULL,
+ "display help about the " COMMAND_NAME " command" },
+
+ { CLI_OPT_TYPE_SWITCH, NULL, 't', &display, DISPLAY_TYPE,
+ CLI_OPT_USAGE_REQUIRED, NULL, "display the type of the object" },
+ { CLI_OPT_TYPE_SWITCH, NULL, 's', &display, DISPLAY_SIZE,
+ CLI_OPT_USAGE_CHOICE, NULL, "display the size of the object" },
+ { CLI_OPT_TYPE_SWITCH, NULL, 'e', &display, DISPLAY_EXISTS,
+ CLI_OPT_USAGE_CHOICE, NULL, "displays nothing unless the object is corrupt" },
+ { CLI_OPT_TYPE_SWITCH, NULL, 'p', &display, DISPLAY_PRETTY,
+ CLI_OPT_USAGE_CHOICE, NULL, "pretty-print the object" },
+ { CLI_OPT_TYPE_ARG, "type", 0, &type_name, 0,
+ CLI_OPT_USAGE_CHOICE, "type", "the type of object to display" },
+ { CLI_OPT_TYPE_ARG, "object", 0, &object_spec, 0,
+ CLI_OPT_USAGE_REQUIRED, "object", "the object to display" },
+ { 0 },
+};
+
+static void print_help(void)
+{
+ cli_opt_usage_fprint(stdout, PROGRAM_NAME, COMMAND_NAME, opts);
+ printf("\n");
+
+ printf("Display the content for the given object in the repository.\n");
+ printf("\n");
+
+ printf("Options:\n");
+
+ cli_opt_help_fprint(stdout, opts);
+}
+
+static int print_odb(git_object *object, display_t display)
+{
+ git_odb *odb = NULL;
+ git_odb_object *odb_object = NULL;
+ const unsigned char *content;
+ git_object_size_t size;
+ int ret = 0;
+
+ /*
+ * Our parsed blobs retain the raw content; all other objects are
+ * parsed into a working representation. To get the raw content,
+ * we need to do an ODB lookup. (Thankfully, this should be cached
+ * in-memory from our last call.)
+ */
+ if (git_object_type(object) == GIT_OBJECT_BLOB) {
+ content = git_blob_rawcontent((git_blob *)object);
+ size = git_blob_rawsize((git_blob *)object);
+ } else {
+ if (git_repository_odb(&odb, git_object_owner(object)) < 0 ||
+ git_odb_read(&odb_object, odb, git_object_id(object)) < 0) {
+ ret = cli_error_git();
+ goto done;
+ }
+
+ content = git_odb_object_data(odb_object);
+ size = git_odb_object_size(odb_object);
+ }
+
+ switch (display) {
+ case DISPLAY_SIZE:
+ if (printf("%" PRIu64 "\n", size) < 0)
+ ret = cli_error_os();
+ break;
+ case DISPLAY_CONTENT:
+ if (p_write(fileno(stdout), content, (size_t)size) < 0)
+ ret = cli_error_os();
+ break;
+ default:
+ GIT_ASSERT(0);
+ }
+
+done:
+ git_odb_object_free(odb_object);
+ git_odb_free(odb);
+ return ret;
+}
+
+static int print_type(git_object *object)
+{
+ if (printf("%s\n", git_object_type2string(git_object_type(object))) < 0)
+ return cli_error_os();
+
+ return 0;
+}
+
+static int print_pretty(git_object *object)
+{
+ const git_tree_entry *entry;
+ size_t i, count;
+
+ /*
+ * Only trees are stored in an unreadable format and benefit from
+ * pretty-printing.
+ */
+ if (git_object_type(object) != GIT_OBJECT_TREE)
+ return print_odb(object, DISPLAY_CONTENT);
+
+ for (i = 0, count = git_tree_entrycount((git_tree *)object); i < count; i++) {
+ entry = git_tree_entry_byindex((git_tree *)object, i);
+
+ if (printf("%06o %s %s\t%s\n",
+ git_tree_entry_filemode_raw(entry),
+ git_object_type2string(git_tree_entry_type(entry)),
+ git_oid_tostr_s(git_tree_entry_id(entry)),
+ git_tree_entry_name(entry)) < 0)
+ return cli_error_os();
+ }
+
+ return 0;
+}
+
+int cmd_cat_file(int argc, char **argv)
+{
+ git_repository *repo = NULL;
+ git_object *object = NULL;
+ git_object_t type;
+ cli_opt invalid_opt;
+ int giterr, ret = 0;
+
+ if (cli_opt_parse(&invalid_opt, opts, argv + 1, argc - 1, CLI_OPT_PARSE_GNU))
+ return cli_opt_usage_error(COMMAND_NAME, opts, &invalid_opt);
+
+ if (show_help) {
+ print_help();
+ return 0;
+ }
+
+ if (git_repository_open_ext(&repo, ".", GIT_REPOSITORY_OPEN_FROM_ENV, NULL) < 0)
+ return cli_error_git();
+
+ if ((giterr = git_revparse_single(&object, repo, object_spec)) < 0) {
+ if (display == DISPLAY_EXISTS && giterr == GIT_ENOTFOUND)
+ ret = 1;
+ else
+ ret = cli_error_git();
+
+ goto done;
+ }
+
+ if (type_name) {
+ git_object *peeled;
+
+ if ((type = git_object_string2type(type_name)) == GIT_OBJECT_INVALID) {
+ ret = cli_error_usage("invalid object type '%s'", type_name);
+ goto done;
+ }
+
+ if (git_object_peel(&peeled, object, type) < 0) {
+ ret = cli_error_git();
+ goto done;
+ }
+
+ git_object_free(object);
+ object = peeled;
+ }
+
+ switch (display) {
+ case DISPLAY_EXISTS:
+ ret = 0;
+ break;
+ case DISPLAY_TYPE:
+ ret = print_type(object);
+ break;
+ case DISPLAY_PRETTY:
+ ret = print_pretty(object);
+ break;
+ default:
+ ret = print_odb(object, display);
+ break;
+ }
+
+done:
+ git_object_free(object);
+ git_repository_free(repo);
+ return ret;
+}
diff --git a/src/cli/main.c b/src/cli/main.c
index d961f659f..4b4223682 100644
--- a/src/cli/main.c
+++ b/src/cli/main.c
@@ -28,7 +28,8 @@ const cli_opt_spec cli_common_opts[] = {
};
const cli_cmd_spec cli_cmds[] = {
- { "help", cmd_help, "Display help information" },
+ { "cat-file", cmd_cat_file, "Display an object in the repository" },
+ { "help", cmd_help, "Display help information" },
{ NULL }
};