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digitalmars.D.learn - executeShell doesn't work but system does

reply "Smoke" Adams <SA2432 gmail.com> writes:
system("cls") works but executeShell doesn't. system is 
depreciated.

What's going on? The docs say that it creates a new process. I 
simply want to clear the console!
Jun 26 2016
next sibling parent reply ag0aep6g <anonymous example.com> writes:
On 06/26/2016 05:37 PM, Smoke Adams wrote:

 system("cls") works but executeShell doesn't. system is depreciated.


Unsolicited spelling correction: no 'i' in "deprecated".


 What's going on? The docs say that it creates a new process. I simply
 want to clear the console!


`system` directly prints its output, `executeShell` returns it in a 
tuple with the status code. Maybe cls works by printing some specific 
clear code. If so, you have to print the output of the command.

This works with `clear` on Linux which seems to behave similarly to 
Windows' cls:

----
void main()
{
     import std.stdio: write, writeln;
     import std.process: executeShell;
     import std.exception: enforce;
     writeln("A");
     auto r = executeShell("clear");
     enforce(r.status == 0);
     write(r.output);
     writeln("B");
}
----

`wait(spawnShell(...))` is the other suggestion from `system`'s 
deprecation message. It works for `clear`, too:

----
void main()
{
     import std.stdio: writeln;
     import std.process: spawnShell, wait;
     writeln("A");
     wait(spawnShell("clear"));
     writeln("B");
}
----
Jun 26 2016
next sibling parent Steven Schveighoffer <schveiguy yahoo.com> writes:
On 6/26/16 12:02 PM, ag0aep6g wrote:

 On 06/26/2016 05:37 PM, Smoke Adams wrote:

 system("cls") works but executeShell doesn't. system is depreciated.




Use spawn-related function, and avoid capturing output instead. Not sure 
if you need to call spawnShell (which creates a new system shell to 
execute the command), it depends on whether cls is a shell builtin or an 
executable.


 Unsolicited spelling correction: no 'i' in "deprecated".


 What's going on? The docs say that it creates a new process. I simply
 want to clear the console!


 `system` directly prints its output, `executeShell` returns it in a
 tuple with the status code. Maybe cls works by printing some specific
 clear code. If so, you have to print the output of the command.


Perhaps not exactly correct, but close enough. When you call 
"executeShell", the subprocess is started with stdout/err sent to a 
pipe, and no console is passed to the subprocess. Probably cls sees it's 
not talking to a console and exits.

-Steve
Jun 27 2016
prev sibling parent "Smoke" Adams <SA2432 gmail.com> writes:
On Sunday, 26 June 2016 at 16:02:18 UTC, ag0aep6g wrote:

 On 06/26/2016 05:37 PM, Smoke Adams wrote:

 [...]


 Unsolicited spelling correction: no 'i' in "deprecated".


 [...]


 `system` directly prints its output, `executeShell` returns it 
 in a tuple with the status code. Maybe cls works by printing 
 some specific clear code. If so, you have to print the output 
 of the command.

 [...]


neither work but

wait(spawnShell("cls"));
Jun 27 2016
prev sibling parent reply Satoshi <satoshi rikarin.org> writes:
On Sunday, 26 June 2016 at 15:37:03 UTC, "Smoke" Adams wrote:

 system("cls") works but executeShell doesn't. system is 
 depreciated.

 What's going on? The docs say that it creates a new process. I 
 simply want to clear the console!



I have problem with executeShell on windows 10 (LDC 1.0.0) too.
When I rewrote it into http://prntscr.com/blc9j8 it works.
Jun 26 2016
parent reply cym13 <cpicard openmailbox.org> writes:
On Sunday, 26 June 2016 at 17:56:08 UTC, Satoshi wrote:

 On Sunday, 26 June 2016 at 15:37:03 UTC, "Smoke" Adams wrote:

 system("cls") works but executeShell doesn't. system is 
 depreciated.

 What's going on? The docs say that it creates a new process. I 
 simply want to clear the console!



 I have problem with executeShell on windows 10 (LDC 1.0.0) too.
 When I rewrote it into http://prntscr.com/blc9j8 it works.


OT but please, refrain from using screenshots. I know it's very 
customary on windows but I can't copy paste code from a 
screenshot to play with it and manually copying is error-prone. 
We manipulate text, let's stay with it.
Jun 26 2016
parent Satoshi <satoshi gshost.eu> writes:
On Sunday, 26 June 2016 at 19:01:07 UTC, cym13 wrote:

 On Sunday, 26 June 2016 at 17:56:08 UTC, Satoshi wrote:

 On Sunday, 26 June 2016 at 15:37:03 UTC, "Smoke" Adams wrote:

 system("cls") works but executeShell doesn't. system is 
 depreciated.

 What's going on? The docs say that it creates a new process. 
 I simply want to clear the console!



 I have problem with executeShell on windows 10 (LDC 1.0.0) too.
 When I rewrote it into http://prntscr.com/blc9j8 it works.


 OT but please, refrain from using screenshots. I know it's very 
 customary on windows but I can't copy paste code from a 
 screenshot to play with it and manually copying is error-prone. 
 We manipulate text, let's stay with it.


Sorry... It's same function as executeImpl just with changed 
byChunk to 1. It corrupt stack when I called the original 
function.

https://github.com/ldc-developers/phobos/blob/aa133b5927bbc5f9669374d5bb0f206f6f68cfe4/std/process.d#L2130
Jun 27 2016