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



NAME
       posix_fallocate - allocate file space

SYNOPSIS
       #define _XOPEN_SOURCE 600
       #include <fcntl.h>

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

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(), subse-
       quent 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 3.25 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                                                        2009-09-30                                         POSIX_FALLOCATE(3)