posix_fallocate — allocate file space
#define _XOPEN_SOURCE 600 #include <stdlib.h>
int
posix_fallocate( |
int | fd, |
off_t | offset, | |
off_t | len) ; |
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.
posix_fallocate
() returns
zero on success, or an error number on failure. Note that
errno
is not set.
fd
is not a
valid file descriptor, or is not opened for
writing.
offset+len
exceeds the maximum file size.
offset
or
len
was less
than 0.
fd
does not
refer to a regular file.
There is not enough space left on the device
containing the file referred to by fd.
fd
refers to
a pipe of file descriptor.
lseek(2), posix_fadvise(2), feature_test_macros(7)
|