52 lines
1.5 KiB
Scheme
52 lines
1.5 KiB
Scheme
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; Copyright (c) 1993-1999 by Richard Kelsey and Jonathan Rees. See file COPYING.
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; Scheme analogues of Posix popen() and pclose() library calls.
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(define (call-with-mumble-pipe input?)
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(lambda (command proc)
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(call-with-values pipe
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(lambda (pipe-for-read pipe-for-write)
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(let ((winner (if input? pipe-for-read pipe-for-write))
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(loser (if input? pipe-for-write pipe-for-read))
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(pid (fork)))
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(if (= pid 0)
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(dynamic-wind
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(lambda () #f)
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(lambda ()
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(close winner)
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(let ((foo (if input? 1 0)))
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(close foo)
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(if (not (= (dup loser) foo))
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(error "dup lost" loser foo)))
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(execv "/bin/sh"
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(vector "sh" "-c" command)))
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(lambda () (exit 1))))
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;; (write `(pid = ,pid)) (newline)
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(close loser)
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(let* ((channel (open-channel winner
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(if input?
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(enum open-channel-option
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raw-input-channel)
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(enum open-channel-option
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raw-output-channel))))
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(port (if input?
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(input-channel->port channel 1024)
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(output-channel->port channel 1024))))
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(call-with-values (lambda () (proc port))
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(lambda vals
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(if input?
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(close-input-port port)
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(close-output-port port))
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;; (display "Waiting.") (newline)
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(call-with-values (lambda () (waitpid pid 0))
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(lambda (pid status)
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;; (write `(status = ,status)) (newline)
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(apply values vals)))))))))))
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(define call-with-input-pipe
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(call-with-mumble-pipe #t))
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(define call-with-output-pipe
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(call-with-mumble-pipe #f))
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