-.\" Copyright (c) 1983 The Regents of the University of California.
-.\" All rights reserved.
+.\" Copyright (c) 1983, 1991, 1993
+.\" The Regents of the University of California. All rights reserved.
.\"
-.\" Redistribution and use in source and binary forms are permitted provided
-.\" that: (1) source distributions retain this entire copyright notice and
-.\" comment, and (2) distributions including binaries display the following
-.\" acknowledgement: ``This product includes software developed by the
-.\" University of California, Berkeley and its contributors'' in the
-.\" documentation or other materials provided with the distribution and in
-.\" all advertising materials mentioning features or use of this software.
-.\" Neither the name of the University nor the names of its contributors may
-.\" be used to endorse or promote products derived from this software without
-.\" specific prior written permission.
-.\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
-.\" WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
-.\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\" notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\" notice, this list of conditions and the following disclaimer in the
+.\" documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\" must display the following acknowledgement:
+.\" This product includes software developed by the University of
+.\" California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\" may be used to endorse or promote products derived from this software
+.\" without specific prior written permission.
.\"
-.\" @(#)truncate.2 6.8 (Berkeley) 6/23/90
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
.\"
-.TH TRUNCATE 2 "June 23, 1990"
-.UC 5
-.SH NAME
-truncate \- truncate a file to a specified length
-.SH SYNOPSIS
-.nf
-.ft B
-truncate(path, length)
-char *path;
-off_t length;
-.PP
-.ft B
-ftruncate(fd, length)
-int fd;
-off_t length;
-.fi
-.SH DESCRIPTION
-.I Truncate
+.\" @(#)truncate.2 8.1 (Berkeley) 6/4/93
+.\"
+.Dd June 4, 1993
+.Dt TRUNCATE 2
+.Os BSD 4.2
+.Sh NAME
+.Nm truncate ,
+.Nm ftruncate
+.Nd truncate a file to a specified length
+.Sh SYNOPSIS
+.Fd #include <unistd.h>
+.Ft int
+.Fn truncate "const char *path" "off_t length"
+.Ft int
+.Fn ftruncate "int fd" "off_t length"
+.Sh DESCRIPTION
+.Fn Truncate
causes the file named by
-.I path
+.Fa path
or referenced by
-.I fd
+.Fa fd
to be truncated to at most
-.I length
+.Fa length
bytes in size. If the file previously
was larger than this size, the extra data
is lost.
With
-.IR ftruncate ,
+.Fn ftruncate ,
the file must be open for writing.
-.SH "RETURN VALUES
+.Sh RETURN VALUES
A value of 0 is returned if the call succeeds. If the call
-fails a \-1 is returned, and the global variable \fIerrno\fP
+fails a -1 is returned, and the global variable
+.Va errno
specifies the error.
-.SH "ERRORS
-.I Truncate
+.Sh ERRORS
+.Fn Truncate
succeeds unless:
-.TP 15
-[ENOTDIR]
+.Bl -tag -width [ENOTDIR]
+.It Bq Er ENOTDIR
A component of the path prefix is not a directory.
-.TP 15
-[EINVAL]
+.It Bq Er EINVAL
The pathname contains a character with the high-order bit set.
-.TP 15
-[ENAMETOOLONG]
+.It Bq Er ENAMETOOLONG
A component of a pathname exceeded 255 characters,
or an entire path name exceeded 1023 characters.
-.TP 15
-[ENOENT]
+.It Bq Er ENOENT
The named file does not exist.
-.TP 15
-[EACCES]
+.It Bq Er EACCES
Search permission is denied for a component of the path prefix.
-.TP 15
-[EACCES]
+.It Bq Er EACCES
The named file is not writable by the user.
-.TP 15
-[ELOOP]
+.It Bq Er ELOOP
Too many symbolic links were encountered in translating the pathname.
-.TP 15
-[EISDIR]
+.It Bq Er EISDIR
The named file is a directory.
-.TP 15
-[EROFS]
+.It Bq Er EROFS
The named file resides on a read-only file system.
-.TP 15
-[ETXTBSY]
+.It Bq Er ETXTBSY
The file is a pure procedure (shared text) file that is being executed.
-.TP 15
-[EIO]
+.It Bq Er EIO
An I/O error occurred updating the inode.
-.TP 15
-[EFAULT]
-.I Path
+.It Bq Er EFAULT
+.Fa Path
points outside the process's allocated address space.
-.PP
-.I Ftruncate
+.El
+.Pp
+.Fn Ftruncate
succeeds unless:
-.TP 15
-[EBADF]
+.Bl -tag -width [ENOTDIR]
+.It Bq Er EBADF
The
-.I fd
+.Fa fd
is not a valid descriptor.
-.TP 15
-[EINVAL]
+.It Bq Er EINVAL
The
-.I fd
+.Fa fd
references a socket, not a file.
-.TP 15
-[EINVAL]
+.It Bq Er EINVAL
The
-.I fd
+.Fa fd
is not open for writing.
-.SH "SEE ALSO"
-open(2)
-.SH BUGS
+.El
+.Sh SEE ALSO
+.Xr open 2
+.Sh BUGS
These calls should be generalized to allow ranges
of bytes in a file to be discarded.
+.Sh HISTORY
+The
+.Nm
+function call appeared in
+.Bx 4.2 .
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