NAME
ar - archive (library) file format
DESCRIPTION
The archive command ar is used to combine several files into
one. Archives are used mainly as libraries to be searched
by the link-editor ld.
A file produced by ar has a magic number at the start, fol-
lowed by the constituent files, each preceded by a file
header. The magic number is 177555(8) (it was chosen to be
unlikely to occur anywhere else). The header of each file
is 16 bytes long:
0-7 file name, null padded on the right
8-11 modification time of the file
12 user ID of file owner
13 file mode
14-15 file size
Each file begins on a word boundary; a null byte is inserted
between files if necessary. Nevertheless the size give
reflects the actual size of the file exclusive of padding.
Notice there is no provision for empty areas in an archive
file.
SEE ALSO
ar (I), ld (I)
BUGS
Names are only 8 characters, not 14. More important, there
isn't enough room to store the proper mode, so ar always
extracts in mode 666.
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