GBBopen 1.5 Reference -- run-external-program

run-external-program

run-external-program

program args &key input output wait => bidirectional-stream, os-process

[Function]

Purpose
Run an external program.

Package :gbbopen-tools

Module :os-interface

Arguments and values

program		A string specifying the name of the program to be run
args		A list of strings passed to `program` as arguments
input		A stream specification (default is `:stream`, see below)
output		A stream specification (default is `:stream`, see below)
wait		A generalized boolean (default is `nil`)
bidirectional-stream		A stream or `nil`
os-process		An implementation-dependent process representation or `nil`

Returns
Two values:

an input, output, or bi-directional stream or nil
an operating-system process representation, if available, or nil

Errors
Use of a true value for wait and a :stream value for input or output is problematic or an error in most Common Lisp implementations.

Description
The values of input and output can be:

:stream (the default) which creates a stream that is returned as the first result value; if both input and output are specified as :stream, a bi-directional stream is created and returned
a string specifying a file to be used as input or output

LispWorks (non-Windows platforms) and SBCL do not use a search path for locating program, the full path must be specified in the program string.

Example

  > (let ((stream (run-external-program "date" nil)))
       (print (read-line stream))
       (close-external-program-stream stream))
  "Mon Jul  4 14:06:04 EDT 2005" 
  >

The GBBopen Project

run-external-program