TRUNCATE(2)TRUNCATE(2)NAME
truncate, ftruncate - truncate a file to a specified length (may
extend)
SYNOPSIS
#include <unistd.h>
int truncate(char *filename, off_t length);
int ftruncate(int fd, off_t length);
DESCRIPTION
Truncate causes the file filename to be set to the length length caus‐
ing data after that size to be lost. If the file is set to a length
larger than the current file size, the new region can be written to but
reads as zeroes. There will be no disk blocks reserved for it. This is
a hole.
Ftruncate does the same thing as truncate but operates on a file
descriptor instead of a filename.
SEE ALSOfcntl(2)4th Berkeley Distribution Feb 13, 2006 TRUNCATE(2)