C Standard Built-in Library Functions

C standard built-in library functions; In this tutorial, you’ll learn standard built-in library functions in C.

C Standard Built-in Library Functions

• What is built-in Library Functions in C
• List of all c standard built-in library functions
• Advantages of Standard built-in Library Functions in C
• Example 1 – Find the length of the string using strlen Function in C

What is built-in Library Functions in C

Standard library functions are functions that have already been created and kept in a file called a library. And can use this library functions to perform certain tasks in C programming languages, such as string handling, mathematical calculations, input/output processing, memory management, and many other operating system services.

For example, You must have used the printf() function in C, whenever you have created the program in c language. This function is under stdio.io library. As follow:

#include <stdio.h>
int main()
{
   printf("Catch me if you can."); 
}

Note that:- The printf() function, is a function of the standard library. which is used to print in C program

List of all c standard built-in library functions

List of Standard Library Functions in c; as follows:

C Header Files	Description
<assert.h>	Program assertion functions
<ctype.h>	Character type functions
<locale.h>	Localization functions
<math.h>	Mathematics functions
<setjmp.h>	Jump functions
<signal.h>	Signal handling functions
<stdarg.h>	Variable arguments handling functions
<stdio.h>	Standard Input/Output functions
<stdlib.h>	Standard Utility functions
<string.h>	String handling functions
<time.h>	Date time functions

Advantages of Standard built-in Library Functions in C

• C library functions is very simple.
• The functions are optimized for performance
• It saves considerable development time
• The functions are portable

Example 1 – Find the length of the string using strlen Function in C

Using the c string standard library function strlen() function find the length of the string in C program; as follows:

#include <stdio.h>
#include <string.h>
int main()
{
   char name[100];
   printf("Enter a string: ");
   scanf("%s",name); 

   // find the length of string and print it
   printf("Length of string a = %zu \n",strlen(name));

   return 0;
}

Output of the above c program; as follows:

Enter a string: tutsmake
Length of string a = 8