Dpkg::IPC - phpMan

Dpkg::IPC(3perl) libdpkg-perl 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.