Why my GTK+ program can't run by double click when I used the PLplot in my program?

[LI Chang-Sheng]

Hi all,
In my the operating system ubuntu14.04, a classical GTK+ program can be run by double click. When the PLplot was used in the program, it could not be run by double click and should run in a terminal. The follow example was given by PLplot. https://sourceforge.net/p/plplot/plplot/ci/master/tree/examples/c/extXdrawable_demo.c
If we cut out the follow Plplot code segment in extXdrawable_demo.c

/*
    plsdev( "xcairo" );
    plsetopt( "drvopt", "external_drawable" );
    plinit();
  #if TO_PIXMAP == 1
    // Here we set up to draw to a pixmap
    xinfo.display  = GDK_PIXMAP_XDISPLAY( a->plotwindow_pixmap );
    xinfo.drawable = GDK_PIXMAP_XID( a->plotwindow_pixmap );
  #else
    // Alternatively, we can do direct to a visible X Window
    xinfo.display  = GDK_WINDOW_XDISPLAY( a->plotwindow->window );
    xinfo.drawable = GDK_WINDOW_XID( a->plotwindow->window );
  #endif
    pl_cmd( PLESC_DEVINIT, &xinfo );
    plenv( 0, 5, 0, 5, 0, 0 );
    plline( 3, x, y );
    plend();
*/

and compiled the code by

gcc extXdrawable_demo.c -o extXdrawable_demo `pkg-config --cflags --libs plplot gtk+-2.0`

A executable file named extXdrawable_demo would be generated. It can be run by double click and a window would show.

If I didn't cut out the above-mentioned Plplot code segment and compiled the code by

gcc extXdrawable_demo.c -o extXdrawable_demo `pkg-config --cflags --libs plplot gtk+-2.0`

The executable file extXdrawable_demo would still be generated. But It cannot be run by double click.
You must run it in a terminal by

./extXdrawable_demo

I don't konw what on earth do PLplot do for the program? Can some one answer my question and give a method to make the extXdrawable_demo run by double click as a classical GTK+ program.

---

Best regards,
LI Chang-Sheng
School of Earth Sciences and Engineering
Nanjing University
163 XIANLIN Road, Nanjing
Jiangsu Province 210023
P.R. of China
E-mail: sheng0619@163.com;

[LI Chang-Sheng]

Hi all,
I find the reason.
In the past , I always set the LD_LIBRARY_PATH in ~/.bashrc.
export LD_LIBRARY_PATH=~/desktop/support_lib/plplot-5.11.0-install/lib
This file just runs together with a new terminal. So If I don't run the terminal, the program would not find the PLplot lib.
Now I set LD_LIBRARY_PATH in /etc/environment. I need not open a terminal for the program, and example1 can be opened from the file browser by double-click.

Best regards,
LI Chang-Sheng
School of Earth Sciences and Engineering
Nanjing University
163 XIANLIN Road, Nanjing
Jiangsu Province 210023
P.R. of China
E-mail: sheng0619@163.com;