A string, a list of strings, a simple-vector of strings, or
nil
.
:input
,
:output
or
:io
.
A type specifier.
A boolean. Not implemented on Microsoft Windows.
A shell type.
A boolean.
On Unix/Linux/Mac OS X/FreeBSD the behavior of
open-pipe
is analogous to that of
popen
in the UNIX library. It creates a pipe to/from a subprocess and returns a stream. The stream can be read from or written to as appropriate.
On Microsoft Windows
open-pipe
calls
CreateProcess
and
CreatePipe
and returns a bidirectional stream.
command is interpreted as by call-system-showing-output.
direction
is a keyword for the stream direction. The default value is
:input
. Bidirectional (I/O) pipes may be created by pasing
:io
. See the example below. This argument is ignored on Microsoft Windows.
element-type
specifies the type of the stream as with open. The default value is
base-char
. This argument is ignored on Microsoft Windows.
interrupt-off
, if
t
, ensures that
Ctrl+C
(SIGINT) to the LispWorks image is ignored by the subprocess. This argument is not implemented on Microsoft Windows.
shell-type
specifies the type of shell to run. On Unix-like systems the default value is
"/bin/sh"
. On Microsoft Windows the default value is
"cmd"
. Note that on Windows ME/98/95 you will need to pass
"command"
.
use-pty is useful on Unix-like systems if the sub-process behaves differently when running interactively and non-interactively. When use-pty is non-nil, the input and output of the sub-process are opened using PTY (Pseudo-pty). That means that the sub-process sees its input and output as if they come from an interactive terminal. The PTY also processes special characters such as Ctrl-C the same way that an ordinary TTY does.
use-pty
is probably not useful on Microsoft Windows as there is no concept corresponding to the Unix behavior. If
use-pty
is non-nil then it uses the
CREATE_NEW_PROCESS_GROUP
flag when creating the child, but it is not obvious when this might be useful.
stream supports mixed character and binary I/O in the same way as file streams constructed by open.
CL-USER 1 > (setf *ls* (sys:open-pipe "ls"))
Warning: Setting unbound variable *LS*
#<SYSTEM::PIPE-STREAM "ls">
CL-USER 2 > (loop while
(print (read-line *ls* nil nil)))
"hello"
"othello"
NIL
NIL
CL-USER 3 > (close *ls*)
T
The following example shows you how to use bidirectional pipes.
CL-USER 1 > (with-open-stream
(s (sys:open-pipe "/bin/csh"
:direction :io))
(write-line "whereis ls" s)
(force-output s)
(read-line s))
"ls: /sbin/ls /usr/bin/ls /usr/share/man/man1.Z/ls.1"
NIL
CL-USER 40 > (setf *ls* (sys:open-pipe "dir"))
#<WIN32::TWO-WAY-PIPE-STREAM 205F03F4>
CL-USER 41 > (loop while
(print (read-line *ls* nil nil)))
" Volume in drive Z is lispsrc"
" Volume Serial Number is 82E3-1342"
""
" Directory of Z:\\v42\\delivery-tests"
""
"20/02/02 11:57a <DIR> ."
"20/02/02 11:57a <DIR> .."
"14/02/02 07:04p 6,815,772 othello.exe"
"14/02/02 07:07p 6,553,628 hello.exe"
" 4 File(s) 13,369,400 bytes"
" 3,974,103,040 bytes free"
NIL
NIL
CL-USER 42 > (close *ls*)
T
LispWorks User Guide and Reference Manual - 21 Dec 2011