Improve return value of OS.execute in blocking/non-blocking variants

Initialized the PID to -2, which will be the value returns in blocking-
mode where the PID is not available. (-1 was already taken to signify an
execution failure).

OS::execute will now properly return a non-OK error code when it fails
to execute the target file.

The documentation was rewritten to be very clear about the differences
between blocking and non-blocking mode.

Fixes #19056.
This commit is contained in:
Rémi Verschelde 2018-05-30 12:18:01 +02:00
parent 3d9dffdef7
commit f392650be2
3 changed files with 18 additions and 16 deletions

View file

@ -399,7 +399,7 @@ Error _OS::shell_open(String p_uri) {
int _OS::execute(const String &p_path, const Vector<String> &p_arguments, bool p_blocking, Array p_output) {
OS::ProcessID pid;
OS::ProcessID pid = -2;
List<String> args;
for (int i = 0; i < p_arguments.size(); i++)
args.push_back(p_arguments[i]);
@ -412,6 +412,7 @@ int _OS::execute(const String &p_path, const Vector<String> &p_arguments, bool p
else
return pid;
}
Error _OS::kill(int p_pid) {
return OS::get_singleton()->kill(p_pid);

View file

@ -94,17 +94,24 @@
<argument index="3" name="output" type="Array" default="[ ]">
</argument>
<description>
Execute the file at the given path, optionally blocking until it returns.
Platform path resolution will take place. The resolved file must exist and be executable.
Returns a process id.
For example:
Execute the file at the given path with the arguments passed as an array of strings. Platform path resolution will take place. The resolved file must exist and be executable.
The arguments are used in the given order and separated by a space, so [code]OS.execute('ping', ['-c', '3', 'godotengine.org'])[/code] will resolve to [code]ping -c 3 godotengine.org[/code] in the system's shell.
This method has slightly different behaviour based on whether the [code]blocking[/code] mode is enabled.
When [code]blocking[/code] is enabled, the Godot thread will pause its execution while waiting for the process to terminate. The shell output of the process will be written to the [code]output[/code] array as a single string. When the process terminates, the Godot thread will resume execution.
When [code]blocking[/code] is disabled, the Godot thread will continue while the new process runs. It is not possible to retrieve the shell output in non-blocking mode, so [code]output[/code] will be empty.
The return value also depends on the blocking mode. When blocking, the method will return -2 (no process ID information is available in blocking mode). When non-blocking, the method returns a process ID, which you can use to monitor the process (and potentially terminate it with [method kill]). If the process forking (non-blocking) or opening (blocking) fails, the method will return -1.
Example of blocking mode and retrieving the shell output:
[codeblock]
var output = []
var pid = OS.execute('ls', [], true, output)
OS.execute('ls', ['-l', '/tmp'], true, output)
[/codeblock]
If you wish to access a shell built-in or perform a composite command, a platform specific shell can be invoked. For example:
Example of non-blocking mode, running another instance of the project and storing its process ID:
[codeblock]
var pid = OS.execute('CMD.exe', ['/C', 'cd %TEMP% &amp;&amp; dir'], true, output)
var pid = OS.execute(OS.get_executable_path(), [], false)
[/codeblock]
If you wish to access a shell built-in or perform a composite command, a platform-specific shell can be invoked. For example:
[codeblock]
OS.execute('CMD.exe', ['/C', 'cd %TEMP% &amp;&amp; dir'], true, output)
[/codeblock]
</description>
</method>
@ -527,7 +534,8 @@
<argument index="0" name="pid" type="int">
</argument>
<description>
Kill a process ID (this method can be used to kill processes that were not spawned by the game).
Kill (terminate) the process identified by the given process ID ([code]pid[/code]), e.g. the one returned by [method execute] in non-blocking mode.
Note that this method can also be used to kill processes that were not spawned by the game.
</description>
</method>
<method name="native_video_is_playing">

View file

@ -2209,10 +2209,6 @@ Error OS_Windows::execute(const String &p_path, const List<String> &p_arguments,
argss += String(" \"") + E->get() + "\"";
}
//print_line("ARGS: "+argss);
//argss+"\"";
//argss+=" 2>nul";
FILE *f = _wpopen(argss.c_str(), L"r");
ERR_FAIL_COND_V(!f, ERR_CANT_OPEN);
@ -2239,15 +2235,12 @@ Error OS_Windows::execute(const String &p_path, const List<String> &p_arguments,
I = I->next();
};
//cmdline+="\"";
ProcessInfo pi;
ZeroMemory(&pi.si, sizeof(pi.si));
pi.si.cb = sizeof(pi.si);
ZeroMemory(&pi.pi, sizeof(pi.pi));
LPSTARTUPINFOW si_w = (LPSTARTUPINFOW)&pi.si;
print_line("running cmdline: " + cmdline);
Vector<CharType> modstr; //windows wants to change this no idea why
modstr.resize(cmdline.size());
for (int i = 0; i < cmdline.size(); i++)