glibc/sysdeps/unix/sysv/sysv4/ftruncate.c

38 lines
1.2 KiB
C

/* ftruncate for SVR4 using the fcntl F_FREESP command.
Copyright (C) 1995, 1997 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
/* Truncate the file FD refers to to LENGTH bytes. */
int
ftruncate (fd, length)
int fd;
off_t length;
{
struct flock fl;
memset (&fl, 0, sizeof fl);
fl.l_type = F_WRLCK;
fl.l_start = length;
return fcntl (fd, F_FREESP, &fl);
}