POSIX_FALLOCATE(3)					     Linux Programmer's Manual						POSIX_FALLOCATE(3)

NAME

       posix_fallocate - allocate file space

SYNOPSIS

       #include <fcntl.h>

       int posix_fallocate(int fd, off_t offset, off_t len);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       posix_fallocate():
	   _XOPEN_SOURCE >= 600 || _POSIX_C_SOURCE >= 200112L

DESCRIPTION

       The  function  posix_fallocate()  ensures  that	disk space is allocated for the file referred to by the descriptor fd for the bytes in the
       range starting at offset and continuing for len bytes.  After a successful call to posix_fallocate(), subsequent writes	to  bytes  in  the
       specified range are guaranteed not to fail because of lack of disk space.

       If the size of the file is less than offset+len, then the file is increased to this size; otherwise the file size is left unchanged.

RETURN VALUE

       posix_fallocate() returns zero on success, or an error number on failure.  Note that errno is not set.

ERRORS

       EBADF  fd is not a valid file descriptor, or is not opened for writing.

       EFBIG  offset+len exceeds the maximum file size.

       EINVAL offset was less than 0, or len was less than or equal to 0.

       ENODEV fd does not refer to a regular file.

       ENOSPC There is not enough space left on the device containing the file referred to by fd.

       ESPIPE fd refers to a pipe of file descriptor.

VERSIONS

       posix_fallocate() is available since glibc 2.1.94.

CONFORMING TO

       POSIX.1-2001.

       POSIX.1-2008  says  that  an implementation shall give the EINVAL error if len was 0, or offset was less than 0.  POSIX.1-2001 says that an
       implementation shall give the EINVAL error if len is less than 0, or offset was less than 0, and may give the error if len equals zero.

SEE ALSO

       fallocate(2), lseek(2), posix_fadvise(2), feature_test_macros(7)

COLOPHON

       This page is part of release 3.27 of the Linux man-pages project.  A description of the project, and information about reporting bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.

GNU
								    2010-09-20							POSIX_FALLOCATE(3)