"PROC is the name of Pick operating system's procedure language. PROC is comparable to a UNIX shell script or a DOS/Windows batch file, and has similar features such as control-flow constructs, file manipulation, subroutine calls, and terminal input and output. The PROC language itself consists of terse macro commands. A PROC script contains a sequence of PROC language macros and PICK TCL (Terminal Control Language) commands."@en .