Method invoke_date

src/include/invoke_date.cc:24–48

#include <errno.h>

int utime_t::invoke_date(const std::string& date_str, utime_t *result) {
  char buf[256];

  SubProcess bin_date("/bin/date", SubProcess::CLOSE, SubProcess::PIPE,
						      SubProcess::KEEP);
  bin_date.add_cmd_args("-d", date_str.c_str(), "+%s %N", NULL);

  int r = bin_date.spawn();
  if (r < 0) return r;

  ssize_t n = safe_read(bin_date.get_stdout(), buf, sizeof(buf));

  r = bin_date.join();
  if (r || n <= 0) return -EINVAL;

  uint64_t epoch, nsec;
  std::istringstream iss(buf);

  iss >> epoch;
  iss >> nsec;

  *result = utime_t(epoch, nsec);

  return 0;
}