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.

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

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       project,    and    information    about    reporting    bugs,    can    be    found     at
       http://www.kernel.org/doc/man-pages/.