Function set_input_file

src/csplit.c:605–611

/* Open NAME as standard input.  */

static void
set_input_file (char const *name)
{
  if (! streq (name, "-") && fd_reopen (STDIN_FILENO, name, O_RDONLY, 0) < 0)
    error (EXIT_FAILURE, errno, _("cannot open %s for reading"),
           quoteaf (name));
}

/* Write all lines from the beginning of the buffer up to, but
   not including, line LAST_LINE, to the current output file.