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TRUNCATE(2)		  FreeBSD System Calls Manual		   TRUNCATE(2)

NAME
     truncate, ftruncate -- truncate or	extend a file to a specified length

LIBRARY
     Standard C	Library	(libc, -lc)

SYNOPSIS
     #include <unistd.h>

     int
     truncate(const char *path,	off_t length);

     int
     ftruncate(int fd, off_t length);

DESCRIPTION
     Truncate()	causes the file	named by path or referenced by fd to be	trun-
     cated or extended to length bytes in size.	 If the	file was larger	than
     this size,	the extra data is lost.	 If the	file was smaller than this
     size, it will be extended as if by	writing	bytes with the value zero.
     With ftruncate(), the file	must be	open for writing.

RETURN VALUES
     Upon successful completion, the value 0 is	returned; otherwise the
     value -1 is returned and the global variable errno	is set to indicate the
     error.

ERRORS
     Truncate()	succeeds unless:

     [ENOTDIR]		A component of the path	prefix is not a	directory.

     [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 translat-
			ing 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 ALSO
     open(2)

BUGS
     These calls should	be generalized to allow	ranges of bytes	in a file to
     be	discarded.

     Use of truncate() to extend a file	is not portable.

HISTORY
     The truncate() function call appeared in 4.2BSD.

FreeBSD	9.3			 June 4, 1993			   FreeBSD 9.3

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUES | ERRORS | SEE ALSO | BUGS | HISTORY

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