148 lines
5.6 KiB
Groff
148 lines
5.6 KiB
Groff
.\" Copyright (c) 1990, 1991, 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" 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.
|
|
.\"
|
|
.\" 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.
|
|
.\"
|
|
.\" @(#)ar.5.5 8.1 (Berkeley) 6/9/93
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd June 9, 1993
|
|
.Dt AR 5
|
|
.Os
|
|
.Sh NAME
|
|
.Nm ar
|
|
.Nd archive (library) file format
|
|
.Sh SYNOPSIS
|
|
.Fd #include <ar.h>
|
|
.Sh DESCRIPTION
|
|
The archive command
|
|
.Nm
|
|
combines several files into one.
|
|
Archives are mainly used as libraries of object files intended to be
|
|
loaded using the link-editor
|
|
.Xr ld 1 .
|
|
.Pp
|
|
A file created with
|
|
.Nm
|
|
begins with the ``magic'' string "!<arch>\en".
|
|
The rest of the archive is made up of objects, each of which is composed
|
|
of a header for a file, a possible file name, and the file contents.
|
|
The header is portable between machine architectures, and, if the file
|
|
contents are printable, the archive is itself printable.
|
|
.Pp
|
|
The header is made up of six variable length
|
|
.Tn ASCII
|
|
fields, followed by a
|
|
two character trailer.
|
|
The fields are the object name (16 characters), the file last modification
|
|
time (12 characters), the user and group id's (each 6 characters), the file
|
|
mode (8 characters) and the file size (10 characters).
|
|
All numeric fields are in decimal, except for the file mode which is in
|
|
octal.
|
|
.Pp
|
|
The modification time is the file
|
|
.Fa st_mtime
|
|
field, i.e.,
|
|
.Dv CUT
|
|
seconds since
|
|
the epoch.
|
|
The user and group id's are the file
|
|
.Fa st_uid
|
|
and
|
|
.Fa st_gid
|
|
fields.
|
|
The file mode is the file
|
|
.Fa st_mode
|
|
field.
|
|
The file size is the file
|
|
.Fa st_size
|
|
field.
|
|
The two-byte trailer is the string "\`\en".
|
|
.Pp
|
|
Only the name field has any provision for overflow.
|
|
If any file name is more than 16 characters in length or contains an
|
|
embedded space, the string "#1/" followed by the
|
|
.Tn ASCII
|
|
length of the
|
|
name is written in the name field.
|
|
The file size (stored in the archive header) is incremented by the length
|
|
of the name.
|
|
The name is then written immediately following the archive header.
|
|
.Pp
|
|
Any unused characters in any of these fields are written as space
|
|
characters.
|
|
If any fields are their particular maximum number of characters in
|
|
length, there will be no separation between the fields.
|
|
.Pp
|
|
Objects in the archive are always an even number of bytes long; files
|
|
which are an odd number of bytes long are padded with a newline (``\en'')
|
|
character, although the size in the header does not reflect this.
|
|
.Sh SEE ALSO
|
|
.Xr ar 1 ,
|
|
.Xr stat 2
|
|
.Sh HISTORY
|
|
There have been at least four
|
|
.Nm
|
|
formats.
|
|
The first was denoted by the leading ``magic'' number 0177555 (stored as
|
|
type int).
|
|
These archives were almost certainly created on a 16-bit machine, and
|
|
contain headers made up of five fields.
|
|
The fields are the object name (8 characters), the file last modification
|
|
time (type long), the user id (type char), the file mode (type char) and
|
|
the file size (type unsigned int).
|
|
Files were padded to an even number of bytes.
|
|
.Pp
|
|
The second was denoted by the leading ``magic'' number 0177545 (stored as
|
|
type int).
|
|
These archives may have been created on either 16 or 32-bit machines, and
|
|
contain headers made up of six fields.
|
|
The fields are the object name (14 characters), the file last modification
|
|
time (type long), the user and group id's (each type char), the file mode
|
|
(type int) and the file size (type long).
|
|
Files were padded to an even number of bytes.
|
|
.\" For more information on converting from this format see
|
|
.\" .Xr arcv 8 .
|
|
.Pp
|
|
The current archive format (without support for long character names and
|
|
names with embedded spaces) was introduced in
|
|
.Bx 4.0 .
|
|
The headers were the same as the current format, with the exception that
|
|
names longer than 16 characters were truncated, and names with embedded
|
|
spaces (and often trailing spaces) were not supported.
|
|
It has been extended for these reasons,
|
|
as described above.
|
|
This format first appeared in
|
|
.Bx 4.4 .
|
|
.Sh COMPATIBILITY
|
|
No archive format is currently specified by any standard.
|
|
.At V
|
|
has historically distributed archives in a different format from
|
|
all of the above.
|