posix_fallocate

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.

VERSIONS
       posix_fallocate() is available since glibc 2.1.94.

ATTRIBUTES
       For an explanation of the terms used in this section, see attributes(7).

       ┌──────────────────┬───────────────┬─────────┐
       │Interface         Attribute     Value   │
       ├──────────────────┼───────────────┼─────────┤
       │posix_fallocate() │ Thread safety │ MT-Safe │
       └──────────────────┴───────────────┴─────────┘
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(1), fallocate(2), lseek(2), posix_fadvise(2)

COLOPHON
       This page is part of release 3.53 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                                2013-02-12                 POSIX_FALLOCATE(3)