start method
- @override
Starts a process by running the specified command
.
The first element in command
will be treated as the executable to run,
with subsequent elements being passed as arguments to the executable. It
is left to implementations to decide what element types they support in
the command
list.
Returns a Future<Process>
that completes with a Process instance when
the process has been successfully started. That Process object can be
used to interact with the process. If the process cannot be started, the
returned Future completes with an exception.
Use workingDirectory
to set the working directory for the process. Note
that the change of directory occurs before executing the process on some
platforms, which may have impact when using relative paths for the
executable and the arguments.
Use environment
to set the environment variables for the process. If not
set, the environment of the parent process is inherited. Currently, only
US-ASCII environment variables are supported and errors are likely to occur
if an environment variable with code-points outside the US-ASCII range is
passed in.
If includeParentEnvironment
is true
, the process's environment will
include the parent process's environment, with environment
taking
precedence. Default is true
.
If runInShell
is true
, the process will be spawned through a system
shell. On Linux and OS X, /bin/sh
is used, while
%WINDIR%\system32\cmd.exe
is used on Windows.
Users must read all data coming on the stdout
and stderr
streams of processes started with start. If the user
does not read all data on the streams the underlying system
resources will not be released since there is still pending data.
The following code uses start
to grep for main
in the
file test.dart
on Linux.
ProcessManager mgr = new LocalProcessManager();
mgr.start('grep', ['-i', 'main', 'test.dart']).then((process) {
stdout.addStream(process.stdout);
stderr.addStream(process.stderr);
});
If mode
is ProcessStartMode.normal (the default) a child
process will be started with stdin
, stdout
and stderr
connected.
If mode
is ProcessStartMode.detached a detached process will
be created. A detached process has no connection to its parent,
and can keep running on its own when the parent dies. The only
information available from a detached process is its pid
. There
is no connection to its stdin
, stdout
or stderr
, nor will
the process' exit code become available when it terminates.
If mode
is ProcessStartMode.detachedWithStdio a detached
process will be created where the stdin
, stdout
and stderr
are connected. The creator can communicate with the child through
these. The detached process will keep running even if these
communication channels are closed. The process' exit code will
not become available when it terminated.
The default value for mode
is ProcessStartMode.NORMAL
.
Implementation
@override
Future<Process> start(
covariant List<Object> command, {
String workingDirectory,
Map<String, String> environment,
bool includeParentEnvironment: true,
bool runInShell: false,
ProcessStartMode mode: ProcessStartMode.normal,
}) {
return Process.start(
_getExecutable(command, workingDirectory, runInShell),
_getArguments(command),
workingDirectory: workingDirectory,
environment: environment,
includeParentEnvironment: includeParentEnvironment,
runInShell: runInShell,
mode: mode,
);
}