1 files changed, 159 insertions, 0 deletions
diff --git a/builtin-cat-file.c b/builtin-cat-file.c
new file mode 100644
index 0000000000..f132d583d3
--- /dev/null
+++ b/builtin-cat-file.c
@@ -0,0 +1,159 @@
+/*
+ * GIT - The information manager from hell
+ *
+ * Copyright (C) Linus Torvalds, 2005
+ */
+#include "cache.h"
+#include "exec_cmd.h"
+#include "tag.h"
+#include "tree.h"
+#include "builtin.h"
+
+static void pprint_tag(const unsigned char *sha1, const char *buf, unsigned long size)
+{
+	/* the parser in tag.c is useless here. */
+	const char *endp = buf + size;
+	const char *cp = buf;
+
+	while (cp < endp) {
+		char c = *cp++;
+		if (c != '\n')
+			continue;
+		if (7 <= endp - cp && !memcmp("tagger ", cp, 7)) {
+			const char *tagger = cp;
+
+			/* Found the tagger line.  Copy out the contents
+			 * of the buffer so far.
+			 */
+			write_or_die(1, buf, cp - buf);
+
+			/*
+			 * Do something intelligent, like pretty-printing
+			 * the date.
+			 */
+			while (cp < endp) {
+				if (*cp++ == '\n') {
+					/* tagger to cp is a line
+					 * that has ident and time.
+					 */
+					const char *sp = tagger;
+					char *ep;
+					unsigned long date;
+					long tz;
+					while (sp < cp && *sp != '>')
+						sp++;
+					if (sp == cp) {
+						/* give up */
+						write_or_die(1, tagger,
+							     cp - tagger);
+						break;
+					}
+					while (sp < cp &&
+					       !('0' <= *sp && *sp <= '9'))
+						sp++;
+					write_or_die(1, tagger, sp - tagger);
+					date = strtoul(sp, &ep, 10);
+					tz = strtol(ep, NULL, 10);
+					sp = show_date(date, tz, 0);
+					write_or_die(1, sp, strlen(sp));
+					xwrite(1, "\n", 1);
+					break;
+				}
+			}
+			break;
+		}
+		if (cp < endp && *cp == '\n')
+			/* end of header */
+			break;
+	}
+	/* At this point, we have copied out the header up to the end of
+	 * the tagger line and cp points at one past \n.  It could be the
+	 * next header line after the tagger line, or it could be another
+	 * \n that marks the end of the headers.  We need to copy out the
+	 * remainder as is.
+	 */
+	if (cp < endp)
+		write_or_die(1, cp, endp - cp);
+}
+
+int cmd_cat_file(int argc, const char **argv, const char *prefix)
+{
+	unsigned char sha1[20];
+	enum object_type type;
+	void *buf;
+	unsigned long size;
+	int opt;
+	const char *exp_type, *obj_name;
+
+	git_config(git_default_config);
+	if (argc != 3)
+		usage("git-cat-file [-t|-s|-e|-p|<type>] <sha1>");
+	exp_type = argv[1];
+	obj_name = argv[2];
+
+	if (get_sha1(obj_name, sha1))
+		die("Not a valid object name %s", obj_name);
+
+	opt = 0;
+	if ( exp_type[0] == '-' ) {
+		opt = exp_type[1];
+		if ( !opt || exp_type[2] )
+			opt = -1; /* Not a single character option */
+	}
+
+	buf = NULL;
+	switch (opt) {
+	case 't':
+		type = sha1_object_info(sha1, NULL);
+		if (type > 0) {
+			printf("%s\n", typename(type));
+			return 0;
+		}
+		break;
+
+	case 's':
+		type = sha1_object_info(sha1, &size);
+		if (type > 0) {
+			printf("%lu\n", size);
+			return 0;
+		}
+		break;
+
+	case 'e':
+		return !has_sha1_file(sha1);
+
+	case 'p':
+		type = sha1_object_info(sha1, NULL);
+		if (type < 0)
+			die("Not a valid object name %s", obj_name);
+
+		/* custom pretty-print here */
+		if (type == OBJ_TREE) {
+			const char *ls_args[3] = {"ls-tree", obj_name, NULL};
+			return cmd_ls_tree(2, ls_args, NULL);
+		}
+
+		buf = read_sha1_file(sha1, &type, &size);
+		if (!buf)
+			die("Cannot read object %s", obj_name);
+		if (type == OBJ_TAG) {
+			pprint_tag(sha1, buf, size);
+			return 0;
+		}
+
+		/* otherwise just spit out the data */
+		break;
+	case 0:
+		buf = read_object_with_reference(sha1, exp_type, &size, NULL);
+		break;
+
+	default:
+		die("git-cat-file: unknown option: %s\n", exp_type);
+	}
+
+	if (!buf)
+		die("git-cat-file %s: bad file", obj_name);
+
+	write_or_die(1, buf, size);
+	return 0;
+}