What does the 'co' command do in an IRIX shell

Question

I'm trying to get some legacy fortran code compiled on an SGI workstation. In the Makefile, the lines

.f:
        co $@

do appear. Make exits with the error

sh: co: not found

I tried googling for that program, but to no avail. Does anyone know what this could be, and where to obtain it - given the short name, I hope that it is some kind of standard tool, rather than something specific to this very Makefile.

Answer 1

co is part of the RCS version control suite. It "checks out" the version of the file in question from it's "repository" (which is usually same file name with a ,v suffix sometimes stored in an RCS/ subdirectory).