open-output-pipe

[procedure] open-input-pipe cmdline [mode]

[procedure] open-output-pipe cmdline [mode]

Chicken: see also call-with-input-pipe, call-with-output-pipe, with-input-from-pipe, with-output-to-pipe.

Some implementations allow to use "| cmdline" or "cmdline |" as the filename in open-input-file and open-output-file to achieve the same effects as these.

Gauche has open-input-process-port? and open-output-process-port? which do the same thing.