Two-way Pipes

Two-way pipes combine the functions of input and output pipes. To use a two-way pipe, the filename must consist of the pipe symbol (|) followed by the name of the command. The file should be opened for input-output i-o.

For example:

 select i-o-file
     assign to "| cmd /c sort"
     organization is line sequential.
 fd i-o-file.
 01 i-o-file-record pic x(20).
 procedure division.
     open i-o i-o-file
     write i-o-file-record from "Hello world"
     write i-o-file-record from all "A"
     write i-o-file-record from all "Z"
     write i-o-file-record from x"1a"
     perform until exit
         read i-o-file
          at end
             exit perform
         display i-o-file-record
     close i-o-file

In this example, the program launches the sort process and passes it three lines of text, followed by an end-of-file marker. The program then reads all three lines back from the standard output of the sort process.