lib/full-write.c

   1 /* full-write.c -- an interface to write that retries after interrupts
   2    Copyright (C) 1993, 1994 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 2, or (at your option)
   7    any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software
  16    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17
  18    Copied largely from GNU C's cccp.c.
  19    */
  20
  21 #ifdef HAVE_CONFIG_H
  22 #include <config.h>
  23 #endif
  24
  25 #include <sys/types.h>
  26
  27 #ifdef HAVE_UNISTD_H
  28 #include <unistd.h>
  29 #endif
  30
  31 #include <errno.h>
  32 #ifndef errno
  33 extern int errno;
  34 #endif
  35
  36 /* Write LEN bytes at PTR to descriptor DESC, retrying if interrupted.
  37    Return LEN upon success, write's (negative) error code otherwise.  */
  38
  39 int
  40 full_write (desc, ptr, len)
  41      int desc;
  42      char *ptr;
  43      size_t len;
  44 {
  45   int total_written;
  46
  47   total_written = 0;
  48   while (len > 0)
  49     {
  50       int written = write (desc, ptr, len);
  51       if (written < 0)
  52         {
  53 #ifdef EINTR
  54           if (errno == EINTR)
  55             continue;
  56 #endif
  57           return written;
  58         }
  59       total_written += written;
  60       ptr += written;
  61       len -= written;
  62     }
  63   return total_written;
  64 }