The SYS statement provides access to the system shell (in Windows sometimes called the DOS prompt). Gekko will wait until the SYS statement finishes before it continues.

Syntax

sys <MUTE> statements WORKING = foldername;

MUTE	(Optional). With this option set, the system shell runs silently in Gekko. Alternatively, the system shell output (and error messages) is shown in the Gekko main window.
WORKING	(Optional). If set, the Windows system will use this folder as "starting directory" for the system process. For example, SYS 'dir' working = c:\tools; will show the contents of the c:\tools folder. If WORKING is not indicated, the Gekko working folder is used.
statements	A string with windows system shell commands. You may use SYS without arguments. In that case, the system shell opens up as a separate window.

Example

In general, the SYS statement returns the output of the system shell, for instance:

sys 'dir'; //shows the list of files in the working folder

You can use the SYS statement for file managing:

sys 'copy file1.txt file2.txt';

or for more complex tasks or jobs

sys 'start /wait gnuplot p1.prg';

If you need to insert scalar values, just use {}-parentheses. For instance:

%name1 = 'file1';
%name2 = 'file2';
sys 'copy {%name}.txt {%name2}.txt';

To open up the system shell in a separate window for interactive use, call SYS without arguments.

sys;

Note

Note the use of single quotes when using SYS.

•To call R via SYS, use for instance sys '""C:\Program Files\R\R-3.6.2\bin\rscript.exe" --no-save "C:\Gekko\Files\test.r""';

•To call Python vis SYS, use for instance sys '""c:\Program Files\Python36_64\python.exe" -u "C:\Gekko\Files\test.py""';

The use of "-quotes makes it possible to use blanks etc. in the file paths. When called like this, both R and Python will return screen output to Gekko while the R/Python program runs.