NAME
prealloc — preallocate disk storage
DESCRIPTION
prealloc
preallocates at least
size
bytes of disk space for an ordinary file
name,
creating the file if
name
does not already exist.
The space is allocated in an implementation-dependent fashion
for fast sequential reads and writes of the file.
prealloc
fails and no disk space is allocated if
name
already exists and is not an ordinary file of zero length,
if insufficient space is left on disk, or if
size
exceeds the maximum file size or the file size limit of the process (see
ulimit(2)).
The file is zero-filled.
DIAGNOSTICS
prealloc
returns one of the following values upon completion:
- 0
Successful completion.
- 1
name
already exists and is not an ordinary file of zero length.
- 2
There is insufficient room on the disk.
- 3
size
exceeds file size limits.
EXAMPLES
The following example preallocates 50000 bytes for the file
myfile:
WARNINGS
Allocation of file space is highly dependent on current disk usage.
A successful return does not indicate how fragmented
the file actually might be if the disk is approaching its capacity.
AUTHOR
prealloc
was developed by HP.
