Compiling C Program in Linux Part 1

Most of Linux are written in C. To compile C program we need a minimum of the follow packages:

• Gcc – the compiler for C program
• Glibc – contains standard C libraries
• Glibc-devel – contain standard headers file
• Binutils – contains various utilities such as assembler and linker

Writing C Program

You can use many tools in write C code. The most popular tool is vim and gedit. Listed below is a list of tools.

GUI (Graphic User Interface) Editing Tools

• gedit
• geany
• Eclipse

Command Line Editing Tools

• vim
• vi
• Emacs

A Simple C Program
Listed below is a simple C program called sick.c

#include <stdio.h>
int main()
{
     printf ("Sick of printing hello world!\n");
     return 0;
}

To compile the program

$gcc -Wall sick.c -o verysick

The option -Wall display all possible warning (-W is for warning and all is to display all possible warnings) and -o indicate to the compiler that user want the output to be name after the -o option.

To run the program indicate the complete path or

$./verysick

Below is a more complex C program called tvm.c

#include <stdio.h>
#include <math.h>

double tvm (double rate, int terms, double principal);

int main ( )
{
 double myrate;
 int myterm;
 double myprincipal;
 double myreturn;

 printf ("Please enter the following:\n");
 printf ("Rate of return: ");
 scanf ("%lf", &myrate);
 printf ("\n");

 printf ("Number of terms:(No decimals): ");
 scanf ("%d", &myterm);
 printf ("\n");

 printf ("The principal amount: ");
 scanf ("%lf", &myprincipal);
 printf ("\n");

 myreturn = tvm (myrate, myterm, myprincipal);
 printf ("Your return after %d term is $%.2lf.\n", myterm, myreturn);

 return 0;
}

double tvm (double rate, int terms, double principal)
{
 double dn;
 double pp;
 dn = terms;

 pp = pow (1+rate, dn);
 return principal * pp;
} 

To compile the program

$gcc -Wall tvm.c -lm -o tvm

The additional option -lm is required so that the compiler will search for the math library in reference to including math.h. -l is the option for library. The math library is libm.a. You can omit the prefix lib and .a.

To run the program indicate the complete path or

$./tvm 

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