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)
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