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/* 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 2, 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; see the file COPYING. If not, write to the Free Software
Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA. */
#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
#ifndef SEEK_CUR
# define SEEK_CUR 1
#endif
/* Read LEN bytes from FD into BUF. Retry the read on EINTR. Any other
error causes the loop to break. */
ssize_t
zread (fd, buf, len)
int fd;
char *buf;
size_t len;
{
ssize_t r;
while ((r = read (fd, buf, len)) < 0 && errno == EINTR)
;
return r;
}
/* Read LEN bytes from FD into BUF. Retry the read on EINTR, up to three
interrupts. Any other error causes the loop to break. */
#ifdef NUM_INTR
# undef NUM_INTR
#endif
#define NUM_INTR 3
ssize_t
zreadintr (fd, buf, len)
int fd;
char *buf;
size_t len;
{
ssize_t r;
int nintr;
for (nintr = 0; ; )
{
r = read (fd, buf, len);
if (r >= 0)
return r;
if (r == -1 && errno == EINTR)
{
if (++nintr > NUM_INTR)
return -1;
continue;
}
return r;
}
}
/* Read one character from FD and return it in CP. Return values are as
in read(2). This does some local buffering to avoid many one-character
calls to read(2), like those the `read' builtin performs. */
static char lbuf[128];
static size_t lind, lused;
ssize_t
zreadc (fd, cp)
int fd;
char *cp;
{
ssize_t nr;
if (lind == lused || lused == 0)
{
nr = zread (fd, lbuf, sizeof (lbuf));
lind = 0;
if (nr <= 0)
{
lused = 0;
return nr;
}
lused = nr;
}
if (cp)
*cp = lbuf[lind++];
return 1;
}
void
zreset ()
{
lind = lused = 0;
}
/* Sync the seek pointer for FD so that the kernel's idea of the last char
read is the last char returned by zreadc. */
void
zsyncfd (fd)
int fd;
{
off_t off;
int r;
off = lused - lind;
r = 0;
if (off > 0)
r = lseek (fd, -off, SEEK_CUR);
if (r >= 0)
lused = lind = 0;
}
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