CLCcodingHelpDemo-3

Open 'side4linux' and click on 'Project>New Project' in the Main Menu.
Select 'Command Line 'C' Program' and click on 'NEXT' in the 'Select New Project Type' Dialog Box.
Select the 'PRODUCTS' Product Area in the Product Selection Dialog and click on 'OK',
Select 'MC-1' from the Product Area selection Combo Box and click on the 'Next' button,
In the New Project dialog enter the name of 'trydynamiclib' and click on 'Build'.
Once the Project is 'Built', close and then re-open it to let things settle into place.
'Project>Close Project'
'Project>Open Project'
Double click on the 'PRODUCTS' Product Area,
Double click on the 'MC1' Product,
In the file dialog double click the 'CLC' folder, this takes you to where command line 'C' language projects are kept.
Double click on 'Trydynamiclib', this opens the 'Trydynamiclib' project folder.
Double click on 'trydynamiclib.prf', this opens the 'Trydynamiclib' project file.
Left click the tabs on the left hand side of the 'Notebook' and notice the file tree results, this is the 'Project File Tree Explorer'

Visual ( nothing here )
Files ( main )
D-Libs ( m ) = maths 'libm.so' dynamic library added automatically by the new project process.
I-Libs ( Internal Static libraries, but nothing here, yet. )

Click on the 'TXT' Toolbutton and open 'main.c' and edit it to be the same as follows, then click on the 'Build' Toolbutton,

Filename

Contents

main.c

#define DegreeToRadian 57.295779506

#include <stdio.h>
#include <stdarg.h>
#include <math.h> // this is added so that we can link to the external maths library 'libm.so'

int main(int argc, char *argv[])
{ // calculating the trig. sine of the angle 45 degrees
double answer = 0.0, radianAngle = 0.0;

radianAngle = 45/DegreeToRadian; // need radians because this is what the sin() function expects.
answer = sin(radianAngle);
printf("\nThe Trig. Sine of 45 degrees is %4.4lf\n\n ",answer);
return(0);
}

Hint: Make sure that there is a blank line above and below your source code in case the compiler you are using complains!
( a completed copy of this project is stored in -/SIDE/PRODUCTS/MC1/CLC/Testdynamic for your reference in case of trouble )
Note: Notice that files and filenames mentioned here are 'case sensitive' !!!!!

Steps-2/3/4 Result of building and running the program,

On building the program notice in the 'Output Window' the line gcc -Wall -g -g -O2 -o trydynamic main.o -lm
It shows that we are linking to the 'libm.so' dynamic library at runtime.
On running the program we get the following or something similar,

db@wks1:~/Data/Projects/SIDE/DEMOS/SIDEdemos/CLC/Trydynamic/src$ ./trydynamic

The Trig. Sine of 45 degrees is 0.7071

db@wks1:~/Data/Projects/SIDE/DEMOS/SIDEdemos/CLC/Trydynamic/src$

Left click on the 'D-Libs' tag of the 'Project File Tree Explorer',
Left click on the 'm' library in the 'Project File Tree Explorer' to be removed,
From the main menue, click on 'Project>Libraries>Remove Library>Remove Dynamic',
Click on 'OK' in the the acceptance dialog,
Click on 'OK' in the rebuild dialog to rebuild the project file,
Click on the 'Build' Toolbutton to rebuild the program without the removed library.

Result of building the program without 'libm',

On building the program notice in the 'Output Window' the error messages,

main.o: In function `main':
/home/db/Data/Projects/SIDE/DEMOS/SIDEdemos/CLC/Trydynamic/src/main.c:33: undefined reference to `sin'
collect2: ld returned 1 exit status
make[3]: *** [trydynamic] Error 1

Let us now add back the 'libm' library to the 'Trydynamic' project,

In the side4linux IDE, click on 'Project>Libraries>Add Library>Add Dynamic'
In the dialog box that opens type in 'm' ( note leave off the 'lib' as it is presumed to already exist! ).
Click on 'OK' in the dialog and click on 'OK' in the next dialog to re-build the project.
Click on the 'Build' Toolbutton and notice that the build process completes without error!
Click on the 'D-Libs' tag in the 'Project File Tree Explorer' and see that 'm' is there.