TRUNCATE(2)TRUNCATE(2)NAMEtruncate - truncate a file to a specified length
SYNOPSIS
truncate(path, length)
char *path;
off_t length;
ftruncate(fd, length)
int fd;
off_t length;
DESCRIPTION
Truncate causes the file named by path or referenced by fd to be
truncated to at most length bytes in size. If the file previously was
larger than this size, the extra data is lost. With ftruncate, the
file must be open for writing.
RETURN VALUES
A value of 0 is returned if the call succeeds. If the call fails a -1
is returned, and the global variable errno specifies the error.
ERRORS
Truncate succeeds unless:
[ENOTDIR] A component of the path prefix is not a directory.
[EINVAL] The pathname contains a character with the high-order
bit set.
[ENAMETOOLONG] A component of a pathname exceeded 255 characters, or an
entire path name exceeded 1023 characters.
[ENOENT] The named file does not exist.
[EACCES] Search permission is denied for a component of the path
prefix.
[EACCES] The named file is not writable by the user.
[ELOOP] Too many symbolic links were encountered in translating
the pathname.
[EISDIR] The named file is a directory.
[EROFS] The named file resides on a read-only file system.
[ETXTBSY] The file is a pure procedure (shared text) file that is
being executed.
[EIO] An I/O error occurred updating the inode.
[EFAULT] Path points outside the process's allocated address
space.
Ftruncate succeeds unless:
[EBADF] The fd is not a valid descriptor.
[EINVAL] The fd references a socket, not a file.
[EINVAL] The fd is not open for writing.
SEE ALSOopen(2)BUGS
These calls should be generalized to allow ranges of bytes in a file to
be discarded.
4.2 Berkeley Distribution March 29, 1986 TRUNCATE(2)