The what command is used to find identifying information in any UNIX system file whose name is given as an argument. No keyletters are accepted. The what command searches the given file(s) for all occurrences of the string @(#), which is the replacement for the %Z% ID keyword (see the get(1) page). It prints on the standard output whatever follows the string until the first double quote (``"''), greater than symbol (>), backslash (\), new-line, null, or nonprinting character.
For example, if an SCCS file called s.prog.c (a C language source file) contains the following line
char id= "%W%";and the command
$ get -r3.4 s.prog.cis used, the resulting g-file is compiled to produce prog.o and a.out. Then, the command
$ what prog.c prog.o a.outproduces
prog.c: prog.c: 3.4 prog.o: prog.c: 3.4 a.out: prog.c: 3.4
The string searched for by what need not be inserted with an ID keyword of get; it may be inserted in any convenient manner.