Builtin git-cat-file
Signed-off-by: Timo Hirvonen <tihirvon@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
diff --git a/builtin-cat-file.c b/builtin-cat-file.c
new file mode 100644
index 0000000..8ab136e
--- /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;
+}
