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.
SEE ALSO
Dpkg, Dpkg::ErrorHandling
1.21.22 2023-05-11 Dpkg::IPC(3perl)
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