+#include "exec_cmd.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;
+}