Builtin git-cat-file

Signed-off-by: Timo Hirvonen <tihirvon@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 167 insertions, 0 deletions

diff --git a/builtin-cat-file.c b/builtin-cat-file.c
new file mode 100644
index 0000000000..8ab136e981
--- /dev/null
+++ b/builtin-cat-file.c
@@ -0,0 +1,167 @@
+/*
+ * 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 flush_buffer(const char *buf, unsigned long size)
+{
+	while (size > 0) {
+		long ret = xwrite(1, buf, size);
+		if (ret < 0) {
+			/* Ignore epipe */
+			if (errno == EPIPE)
+				break;
+			die("git-cat-file: %s", strerror(errno));
+		} else if (!ret) {
+			die("git-cat-file: disk full?");
+		}
+		size -= ret;
+		buf += ret;
+	}
+}
+
+static int 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.
+			 */
+			flush_buffer(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 */
+						flush_buffer(tagger,
+							     cp - tagger);
+						break;
+					}
+					while (sp < cp &&
+					       !('0' <= *sp && *sp <= '9'))
+						sp++;
+					flush_buffer(tagger, sp - tagger);
+					date = strtoul(sp, &ep, 10);
+					tz = strtol(ep, NULL, 10);
+					sp = show_date(date, tz);
+					flush_buffer(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)
+		flush_buffer(cp, endp - cp);
+	return 0;
+}
+
+int cmd_cat_file(int argc, const char **argv, char **envp)
+{
+	unsigned char sha1[20];
+	char type[20];
+	void *buf;
+	unsigned long size;
+	int opt;
+
+	setup_git_directory();
+	git_config(git_default_config);
+	if (argc != 3)
+		usage("git-cat-file [-t|-s|-e|-p|<type>] <sha1>");
+	if (get_sha1(argv[2], sha1))
+		die("Not a valid object name %s", argv[2]);
+
+	opt = 0;
+	if ( argv[1][0] == '-' ) {
+		opt = argv[1][1];
+		if ( !opt || argv[1][2] )
+			opt = -1; /* Not a single character option */
+	}
+
+	buf = NULL;
+	switch (opt) {
+	case 't':
+		if (!sha1_object_info(sha1, type, NULL)) {
+			printf("%s\n", type);
+			return 0;
+		}
+		break;
+
+	case 's':
+		if (!sha1_object_info(sha1, type, &size)) {
+			printf("%lu\n", size);
+			return 0;
+		}
+		break;
+
+	case 'e':
+		return !has_sha1_file(sha1);
+
+	case 'p':
+		if (sha1_object_info(sha1, type, NULL))
+			die("Not a valid object name %s", argv[2]);
+
+		/* custom pretty-print here */
+		if (!strcmp(type, tree_type))
+			return execl_git_cmd("ls-tree", argv[2], NULL);
+
+		buf = read_sha1_file(sha1, type, &size);
+		if (!buf)
+			die("Cannot read object %s", argv[2]);
+		if (!strcmp(type, tag_type))
+			return pprint_tag(sha1, buf, size);
+
+		/* otherwise just spit out the data */
+		break;
+	case 0:
+		buf = read_object_with_reference(sha1, argv[1], &size, NULL);
+		break;
+
+	default:
+		die("git-cat-file: unknown option: %s\n", argv[1]);
+	}
+
+	if (!buf)
+		die("git-cat-file %s: bad file", argv[2]);
+
+	flush_buffer(buf, size);
+	return 0;
+}