- if (len >= sizeof(buf))
- die("unreasonnable trace length");
-
- /* Get the argv string. */
- argv_str = sq_quote_argv(argv, count);
- argv_len = strlen(argv_str);
-
- write_or_whine_pipe(fd, buf, len, err_msg);
- write_or_whine_pipe(fd, argv_str, argv_len, err_msg);
- write_or_whine_pipe(fd, "\n", 1, err_msg);
+ if (len >= strbuf_avail(&buf)) {
+ strbuf_grow(&buf, len - strbuf_avail(&buf) + 128);
+ va_start(ap, fmt);
+ len = vsnprintf(buf.buf, strbuf_avail(&buf), fmt, ap);
+ va_end(ap);
+ if (len >= strbuf_avail(&buf))
+ die("broken vsnprintf");
+ }
+ strbuf_setlen(&buf, len);