coreutils/lib/safe-read.c
1995-01-08 19:33:34 +00:00

61 lines
1.4 KiB
C

/* safe-read.c -- an interface to read that retries after interrupts
Copyright (C) 1993, 1994 Free Software Foundation, Inc.
This program 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 2, or (at your option)
any later version.
This program 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 this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <sys/types.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <errno.h>
#ifndef errno
extern int errno;
#endif
/* Read LEN bytes at PTR from descriptor DESC, retrying if interrupted.
Return the actual number of bytes read, zero for EOF, or negative
for an error. */
int
safe_read (desc, ptr, len)
int desc;
char *ptr;
int len;
{
int n_chars;
if (len <= 0)
return len;
#ifdef EINTR
do
{
n_chars = read (desc, ptr, len);
}
while (n_chars < 0 && errno == EINTR);
#else
n_chars = read (desc, ptr, len);
#endif
return n_chars;
}