ar – archive (library) file format|
The archive command ar(1) is used to combine several files into
one. Archives are used mainly as libraries to be searched by the
loaders 2l(1) et al. |
A file produced by ar has a magic string at the start, followed
by the constituent files, each preceded by a file header. The
magic number and header layout as described in the include file
Each file begins on an even (0 mod 2) boundary; a newline is inserted between files if necessary. Nevertheless size reflects the actual size of the file exclusive of padding.
When all members of an archive are object files of the same architecture, ar automatically adds an extra file, named __.SYMDEF, as the first member of the archive. This file contains an index used by the loaders to locate all externally defined text and data symbols in the archive.
There is no provision for empty areas in an archive file.
ar(1), 2l(1), nm(1), stat(2)|
The uid and gid fields are unused in Plan 9. They provide compatibility
with Unix ar format.|