An archive with such an index speeds up linking to the library, and allows routines in the library to call each other without regard to their placement in the archive. If an archive lacks the table, another form of ar called ranlib can be used to add just the table.
Most operations can also accept further files arguments, specifying particular files to operate on.
If you wish, you may begin the first command-line argument with a dash. Use this operation to move members in an archive. The ordering of members in an archive can make a difference in how programs are linked using the library, if a symbol is defined in more than one member. If you specify no files , all the files in the archive are printed. If one of the files named in files doesn't exist, ar displays an error message, and leaves undisturbed any existing members of the archive matching that name.