RE: [Jython-users] How to call external commands

[Joseph S. B. I. <jo...@ba...>]

Brian Zimmer a =E9crit:
> Here's an extremely simple example (by no means production, but could=

> get you on your way):

Here's what I've been using.
For outwriter and errwriter, one can pass either PrintStreams,
OutputStreamWriters, or (if you don't care about the output) None.


execvbuf =3D zeros(8192, "c")

def execv(name, outwriter, errwriter):

    # I don't know why we need to check for PrintStream,
    # given that instanceof(PrintStream, OutputStream)...
    # or maybe I need a mix of isinstance() and issubclass()...
    #
    if isinstance(outwriter, OutputStream) or isinstance(outwriter, Pri=
ntStream):
        outwriter =3D OutputStreamWriter(outwriter)
    if isinstance(errwriter, OutputStream) or isinstance(errwriter, Pri=
ntStream):
        errwriter =3D OutputStreamWriter(errwriter)

    process =3D getRuntime().exec(name)
    stdout =3D InputStreamReader(process.getInputStream())
    stderr =3D InputStreamReader(process.getErrorStream())

    while 1:
        if stdout <> None:
            if stdout.ready():
                n =3D stdout.read(execvbuf)
                if n =3D=3D -1:
                    stdout =3D None
                    print "stdout now None"
                    continue
                if outwriter <> None:
                    outwriter.write(execvbuf, 0, n)
                    continue
        if stderr <> None:
            if stderr.ready():
                n =3D stderr.read(execvbuf)
                if n =3D=3D -1:
                    stderr =3D None
                    print "stderr now None"
                    continue
                if errwriter <> None:
                    errwriter.write(execvbuf, 0, n)
                    continue
        try:
            status =3D process.exitValue()
            if status <> 0:
                print "%s returned status %d" % (name, status)
            return status
        except:
            sleep(200)