phpman > perldoc > Dpkg::IPC(3perl)

NAME
    Dpkg::IPC - helper functions for IPC

DESCRIPTION
    Dpkg::IPC offers helper functions to allow you to execute other programs in an easy, yet
    flexible way, while hiding all the gory details of IPC (Inter-Process Communication) from you.

FUNCTIONS
    $pid = spawn(%opts)
        Creates a child process and executes another program in it. The arguments are interpreted as
        a hash of options, specifying how to handle the in and output of the program to execute.
        Returns the pid of the child process (unless the wait_child option was given).

        Any error will cause the function to exit with one of the Dpkg::ErrorHandling functions.

        Options:

        exec
            Can be either a scalar, i.e. the name of the program to be executed, or an array
            reference, i.e. the name of the program plus additional arguments. Note that the program
            will never be executed via the shell, so you can't specify additional arguments in the
            scalar string and you can't use any shell facilities like globbing.

            Mandatory Option.

        from_file, to_file, error_to_file
            Filename as scalar. Standard input/output/error of the child process will be redirected
            to the file specified.

        from_handle, to_handle, error_to_handle
            Filehandle. Standard input/output/error of the child process will be dup'ed from the
            handle.

        from_pipe, to_pipe, error_to_pipe
            Scalar reference or object based on IO::Handle. A pipe will be opened for each of the
            two options and either the reading ("to_pipe" and "error_to_pipe") or the writing end
            ("from_pipe") will be returned in the referenced scalar. Standard input/output/error of
            the child process will be dup'ed to the other ends of the pipes.

        from_string, to_string, error_to_string
            Scalar reference. Standard input/output/error of the child process will be redirected to
            the string given as reference. Note that it wouldn't be strictly necessary to use a
            scalar reference for "from_string", as the string is not modified in any way. This was
            chosen only for reasons of symmetry with "to_string" and "error_to_string". "to_string"
            and "error_to_string" imply the "wait_child" option.

        wait_child
            Scalar. If containing a true value, wait_child() will be called before returning. The
            return value of spawn() will be a true value, not the pid.

        nocheck
            Scalar. Option of the wait_child() call.

        timeout
            Scalar. Option of the wait_child() call.

        chdir
            Scalar. The child process will chdir in the indicated directory before calling exec.

        env Hash reference. The child process will populate %ENV with the items of the hash before
            calling exec. This allows exporting environment variables.

        delete_env
            Array reference. The child process will remove all environment variables listed in the
            array before calling exec.

        sig Hash reference. The child process will populate %SIG with the items of the hash before
            calling exec. This allows setting signal dispositions.

        delete_sig
            Array reference. The child process will reset all signals listed in the array to their
            default dispositions before calling exec.

    wait_child($pid, %opts)
        Takes as first argument the pid of the process to wait for. Remaining arguments are taken as
        a hash of options. Returns nothing. Fails if the child has been ended by a signal or if it
        exited non-zero.

        Options:

        cmdline
            String to identify the child process in error messages. Defaults to "child process".

        nocheck
            If true do not check the return status of the child (and thus do not fail it has been
            killed or if it exited with a non-zero return code).

        timeout
            Set a maximum time to wait for the process, after that kill the process and fail with an
            error message.

CHANGES
  Version 1.02 (dpkg 1.18.0)
    Change options: wait_child() now kills the process when reaching the 'timeout'.

  Version 1.01 (dpkg 1.17.11)
    New options: spawn() now accepts 'sig' and 'delete_sig'.

  Version 1.00 (dpkg 1.15.6)
    Mark the module as public.

SEE ALSO
    Dpkg, Dpkg::ErrorHandling