/* zwrite - write contents of buffer to file descriptor, retrying on error *//* Copyright (C) 1999-2002 Free Software Foundation, Inc.   This file is part of GNU Bash, the Bourne Again SHell.   Bash is free software: you can redistribute it and/or modify   it under the terms of the GNU General Public License as published by   the Free Software Foundation, either version 3 of the License, or   (at your option) any later version.   Bash is distributed in the hope that it will be useful,   but WITHOUT ANY WARRANTY; without even the implied warranty of   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the   GNU General Public License for more details.   You should have received a copy of the GNU General Public License   along with Bash.  If not, see <http://www.gnu.org/licenses/>.*/#include <config.h>#include <sys/types.h>#if defined (HAVE_UNISTD_H)#  include <unistd.h>#endif#include <errno.h>#if !defined (errno)extern int errno;#endif/* Write NB bytes from BUF to file descriptor FD, retrying the write if   it is interrupted.  We retry three times if we get a zero-length   write.  Any other signal causes this function to return prematurely. */intzwrite (fd, buf, nb)     int fd;     char *buf;     size_t nb;{  int n, i, nt;  for (n = nb, nt = 0;;)    {      i = write (fd, buf, n);      if (i > 0)	{	  n -= i;	  if (n <= 0)	    return nb;	  buf += i;	}      else if (i == 0)	{	  if (++nt > 3)	    return (nb - n);	}      else if (errno != EINTR)	return -1;    }}