C Tutorial

C Tutorial C Language Environment Setup Execution flow of C program C Data type C Token Variable in C Operators in C Comments in C

C Functions

User Defined Functions in C Built-in functions in C Types of Function in C Inbuilt Functions in C Static() Function in C pow() function in C Assert() Function fgets() function Ftell() Function getc() function getch() function gets() function Pi() Function Write() function abs() function in C Ferror() in c fopen() function in C Beep() function in C Cbrt() function in C Hook() function in C Isalnum() function in C Simple hash() function in C strcat() Function in C C printf() and Scanf() Use of free() function in C Floor() Function in C Free() Function in C Unformatted input() and output() function in C tolower() Function in C fprintf() and fscanf() in C Sprintf() in C fork() in C isupper() in C Perror() in C Strcmp() Function in C String Functions in C Strrev() function in C exit() and return in C execlp() function in C realloc() in C strftime() function in C Strsep() function in C strstr() function in C Ceil() function in C Malloc() function in C Realloc() function in C Fseek() Function in C Pure Virtual Function in C Ceil() and Floor() in C putchar() in C kbhit() function in C bzero() Function in C atan2() Function in C atof() Function in C getopt() Function in C seof() Function in C getw() and putw() Function in C strdup() Function in C Usleep() function in C getpid() and getppid() function in C strcasecmp() function in C gotoxy() function in C strupr() function in C Free Function in C Language frewind() Function in C

C Programs

infix To Postfix Program in C Armstrong program in C using function Factorial Program in C using For Loop Factorial Program in C Using While Loop Prime Number Program in C using for Loop C program to find factorial of a number using Recursion Fibonacci series program in C using Recursion C Program to find the Roots of a Quadratic Equation C Program Swap Numbers in cyclic order Using Call by Reference C Program to Find Largest Number Using Dynamic Memory Allocation C Program to Find the Largest Number using Ternary Operator C/C++ Program to Find the Size of int, float, double and char Multiplication table program in C using For loop C Program for Mean and Median of an Unsorted Array C program that does not Suspend when Ctrl+Z is Pressed Write a program that produces different results in C and C++ SJF Scheduling Program in C Union Program in C GCD program in C Bit Stuffing Program in C Arithmetic Progression Program in C Binomial Coefficient Program in C C Program to find the size of a File GCD program of two numbers in C C Program for Extended Euclidean algorithms C Program of Fencing the Ground Compound interest Program in C Distance Vector Routing Protocol Program in c DSA Program in C Simple Programs in C Language Assignment Operator Program in C Caesar Cipher Program in C CRC Program in C Deadlock Detection Program in C C Program to find ASCII value of a character 1 2 3 4 Series Program in C C Program for Polynomial Addition C Program to Count the Number of Vowels in a String Complex C Programs Addition Program in C Calculator Program in C C Program to Read and Print an Employee's Detail Using Structure C Program to Find Area and Perimeter of Circle C Program to Check Whether a Given Number is Even or Odd C Program to Make a Simple Calculator Using Switch Case Insertion Sort Program in C Leap Year Program in C Simple interest Program in C Patterm Program in C C Program to Print Table from 1 to 10 Power of 2 Program in C Program to Swap two numbers using Pointers in C Stack program in C C Program For String Concatenation C Program to Calculate Electricity Bill C Program to Convert Decimal to Binary without using Array C Program to Convert Decimal to Hexadecimal C Program to Draw a Circle C Program for Customer Billing System C Program to Reverse a Linked List C Program to Store Inventory System using Structures C Program to Swap Two Numbers Using Call by Reference C Program Using Segmentation Fault C Program Using Structures Employee Details C Program For Matrix Multiplication C Program to Print a Matrix C Program Using Recursion C Program For Sine Series C Program to Find the Square Root Of a Number C Program For Union Of Sets C Program to Access The Array Elements Using Pointers C Program to Add Two integers C Program to Find Gcd Of Two Numbers C Program to Swap 2 Numbers Marksheet Program in C First and Follow Programs in C Checksum Program in C Alphabet Pattern Programs in C Bellman Ford Algorithm Program in C Fcfs Program in C C Program to Calculate Compound Interest C Program to Calculate Percentage C Program to Find Sum Of Array Elements C Program to Find The Rank Of a Matrix C Program to Optimal Page Replacement Algorithm C Program to Swap Two Numbers Without Using a Third Variable Binary Tree Program in C Client Server Program in C Program to Check Balanced Parenthesis in C ATM Program in C C Program to Check Student is Pass or Fail C Program to Delete An Element in An Array C Program to Find Factors of a Number C Program to Generate the Fibonacci Triangle Program For Average of 5 Numbers in C Program to Convert Decimal to Hexadecimal in C Binomial Heap Program in C C Program to Find the Largest Element in An Array C Program to Search An Element in An Array C Program to Sort An Array in Descending Order Strssen Matrix Multiplication Program in C Vigenere Cipher Program in C

C Loops

Loop Statement in C Do-While Loop in C For Loop in C While-Loop in C Entry Control Loop in C Exit control loop in C infinite loop in C Nested loop in C For loop in C Programming

C Examples

Do WHILE LOOP in C Programming Examples For Loop in C Programming Examples While Loop in C programming examples Nested Loops in C Programming Examples Types of Tokens in C with Examples Merge and Merge sort with example in C Example of Iteration in C FIFO Example in the C Language Explain Recursion with example in C

Questions

What are linker and loader in C What is Linked List in C What is a buffer in C What is required in each C Program What is the main in C Why C is a Middle Level Language Why does sizeof(x++) not increment x in C What is String Comparison in C What is a Size of Pointer in C What is increment and Decrement Operator in C What are the differences between C and Embedded C What is Constant in C What is Stack in C What is Data Structure in C Can We Learn Python Without C Can We Learn Java Without Learning C What is Flag in C What is Lvalue in C Which Loop is Faster in C Language What is the Producer Consumer Problem in C What is The Garbage Value in C What is The Function Prototype in C What is FEOF in C

How To

How to Avoid Structure Padding in C How to use atoi() function in C How to use floor() function in C How to use sine() function in C How to use Typedef Struct in C How to delete a file in C How to move a text in C How to create a binary file in C How to convert a number to words in C How to convert a string to hexadecimal in C How to Calculate Time Complexity in C How to include graphics.h in C How to measure time taken by a function in C How to return a Pointer from a Function in C How to Find Square Free Numbers in C How to Declare Boolean in C How to Declare Character in C How to Round up a number in C How to use strlen() in C How to find string length in C using strlen() function How to take input in string in C How to Use Threads in C How to Place Horizontal Tab Character in C How to Reverse a Number in C How to Print Double Quotes in C How to Create Your Own Header Files in C How to Store an Integer in a Char Array in C How can we Initialize an Array in C

Difference

Difference between while and do-while loop in C Difference between rand() and srand() function in C Difference between while and for loop in C Difference between Array and List in C Difference between If and Switch Statement in C Difference between If Else and Nested If Else in C Difference between Pre-increment and Post-increment in C Difference between Scope and Lifetime in C Difference between Argument and Parameter in C Difference between char s[] and char *s in C Difference between Static and Dynamic Memory Allocation in C Difference between parameter and arguments in C Runtime Vs Compile Time in C Const Vs Volatile in C C Vs Java C vs Java Strings Difference Between Float and Double in C Difference Between Malloc and Calloc in C Fseek vs Rewind Function in C Difference between Structure And Union in C With Example

C Interview Questions

Interview Questions on Pointers in C

Misc

Escape Sequence in C C – Storage Classes C Decision control statement Break, continue and goto statement in C Type Casting in C Function in C Recursion in C String in C C Array Pointer in C Dynamic memory allocation C –Structure Nested Structure in C Union in C File Handling in C C pre-processor Sizeof in C Selection Sort in C Scope Of Variables in C Random Access Lseek in C Queue Implementation in C Pseudo Code in C Prototype in C Pointer To Pointer in C Pointer Arithmetic in C Passing Array To Function in C Null Character in C Merge Sort in C Macros in C Library Functions in C Memory Leak in C int in C Goto And Labels in C Fibonacci Series in C Fflush in C Derived Data Types in C Data Types in C Character Set in C Character Class Tests in C Calloc in C C Pointers Arrays in C include in C Clrscr in C String Literals in C Types Of Pointers in C Variables in C Volatile in C LCM of two numbers in C Quick sort in C Static in C function pointer as argument in C Top Array Keywords in C Add two numbers using the function in C Array, Declaring Arrays and Array initialization Limitations of inline Function in C Array Of Structures in C Data Structures And Algorithms in C Types Of Structures in C Use of Structure in C String Handling functions in C Prime Number code in C Fibonacci Series in C Using For Loop Fibonacci series in C using while loop Call Back Function in Embedded C Else If Ladder Heap Sort Nested if-else statement Positioning of file Attributes in C Formatted input and output function in C Snake Game in C C Switch Statements Doubly Linked list in C integer Promotions in C Find the Largest Three Distinct Elements in an Array using C/C++ Loop Questions in C Modulus on Negative Numbers in C Results of Comparison Operations in C and C++ Reverse a Stack using Recursion in C Sum of N numbers in C using For loop C Function Argument and Return Values Keywords in C Bank management system in C Calendar application in C Remove an element from an array in C Socket Programming in C Structure in C Tower of Hanoi in C Variable Declaration in C While Loop Syntax in C Branching Statements in C Comma Operator in C Control statement in C Double Specifier in C Long int in C Palindrome Number in C Run Time Polymorphism in C Types of Array in C Associativity of Operators in C Actual and Formal Parameters Addition of two Numbers in C Advantages of function in C Diffie-Hellman Algorithm in C C and C++ Binary Files Different ways to Declare the Variable as Constant in C Range of int in C GPA Calculator in C Addition of Matrix in C Booleans in C Displaying Array in C Dos.h Header File in C Language Explain the two-way selection in C Fee Management System in C File Operations in C Multiplication Table in C Type Conversion in the C Advantages of Dynamic Memory Allocation in C Armstrong Number in C Banker’s Algorithm in C Binary Search in C with Best and Worst Time Complexity Call by Value and Call by Reference in C Conditional Operator in C Decimal to Binary in C Evaluation of Arithmetic Expression in C Explain the increment and Decrement Operators in C Length of an Array Function in C OpenGL in C Projects on C language in 2023 Purpose of a Function Prototype in C Stdio.h in C Two-Dimensional array in C C Compilers for Windows Functions and Recursion in C Pointer Declaration in C Algorithm for String Palindrome in C Constant Pointer in C Implicit and Explicit in C indirect Recursion in C input and Output functions in C Jump Statement in C Lifetime of a Variable in C Linker Error in C Language Numeric Constant in C Size of Pointer in C Square Root in C Language Static and Dynamic Memory allocation String Declaration in C Strong Number in C Symmetric Matrix in C Types of C Tokens Advantages and Disadvantages of C Language C Programming Errors and Solutions Compilation Errors in C Evaluation of Postfix Expression Using Stack in C Find Leftmost and Rightmost Set Bit of a Number introduction to Dynamic Array in C Print Address in C Ternary Operators in C Array Definition in C Array of Pointers in C Arrow Operator in C Average of Two Numbers in C Binary to Decimal in C Binary to Octal in C BREAK STATEMENT in C C Programming Operators Questions C Programs Asked in interview Bubble Sort Algorithm in C C in Roman Numerals GCC Conflicting Types in C Function Definition in C Format Specifier for Hexadecimal in C Flowchart in C Float in C Fizzbuzz Implementation in C Conditional Statement in C Conio.h functions list in C Constants in C Dynamic Array in C Decision Making Statements in C Continue Statement in C Creation of Thread in C DFS Algorithm in C Dijkstra's Algorithm in C Jump Statements in C Modulus Operator in C Memory Allocation in C Reverse Array in C Recursive Function in C Queue in C Printing Pascal’s Triangle in C Preprocessor Directives in C Perfect Number in C Programming Language Parameter Passing Techniques in C Pascal Triangle in C Swapping of two numbers in C Switch Case Questions in C Transpose of Matrix in C Special Operators in C Static Variable in C Understanding Operator Precedence in C Typedef in C User Defined Datatypes in C Variable initialization in C Void Pointer in C Wild Pointer in C 2D Array in C Priority Queue in C atoi in C Break Statement in C CALL by Reference in C Call by Value in C Circular Buffer in C Digital Clock Code in C Programming Do While Loop Questions in C Flag in C Language Functions in C Function in C Function Declaration in C isDigit in C Macro Expansion in C Modifiers in C Number Crunching in C Number System in C PRAGMA in C Precedence in C Prims Algorithm in C Print Hexadecimal Values in C Return 0 in C Reverse Array in C Stack using array in C Star Pattern in C String input in C Structure and Union in C Transpose of Matrix in C Void in C Math.h in C Prim’s Algorithm in C printf Syntax in C Priority Scheduling Program in C Singly Linked List in C Size of Structure in C Argument in C Bitwise Operator in C Circular Queue in C Compiler in C Convert Char to Int in C ctype.h in C Dangling else Program in C Graphics Programming in C File Handling Functions in C Clock Program in C File in the C Programming Language Identifiers in C Language Area of Triangle Program in C Ascii Table in C Bitwise Operator in C C Programming Errors and Corrections Calling and Called Function in C Characters in C Circular Linked List in C Concatenate String in C Declaration in C Fabs in C Fifo Page Replacement Algorithm in C Getchar Method in C Global Variables in C Memory Management in C Modulus Operator in C Operator Precedence and associativity in C Pointers in C Programming Size Of Data Types in C Size T in C U in the C Programming Language Xor Operator in C Converting Dollars into Rupees in C Form Feed in C Gauss Seidel Method in C Unsigned Char in C Absolute Value in C Function Call in C Dereference Operator in C Different Storage Class Specifiers in C Formal Parameters in C Graph in C Not Equal to in C Print Double in C While Statement in C Deadlock Avoidance Program in C Declaration and Initialisation of Variables in C Declaration of Two Dimensional Array in C Typedef Function Pointer in C ARGC and ARGV in C File Pointer in C Exit 0 in C Increment Operator in C Emirp Number in C Flowchart Symbols in C Lexicographical Order in C Longest Common Subsequence in C Newton Raphson Method in C Sum of Natural Numbers Using Recursion in C Binary Search in Data Structures Using C Binary Tree in Data Structures in C Define Keywords in C Checksum Code in C Distance Vector Routing Program in C Double Type in C Euler Method in C Hollow Triangle Pattern in C Indirection Operator in C Insert Array in C Lagrange Interpolation in C Multiplication Table in C Scansets in C Semaphores in C Spy Number in C BFS Algorithm in C Bisection Method in C Byte Stuffing Program in C Call by Value Function in C Conio in C Constants in C Evaluation Of Prefix Expression Using Stack in C Exception Handling in C Features Of Array in C Find The Power Of Number in C Graphics.h in C Ifndef in C Storage Classes in C Free Function in C Language Callback Function in C Variadic Functions in C Bin Packing Algorithm in C Balanced Parathesis in C Fractional Knapsack Problem in C Double Ended Queue in C Two Level Dictionary Program in C Implementing Data Structures Like Linked Lists or Binary Search Trees in C Exec System Call in C Return Statement in C Bit Manipulation in C Amicable Numbers in C Multiline Macros in C Declare A Character in C Implicit Type Conversion in C C Expressions Printing Double Quotes in C Unary Operators in C Types of Files in C Endianness in C Associativity in C Default Return Type of Function in C Fibonacci Recursion in C Define File in C Structure Within the Structure in C Define Identifier in C Expression Evaluation in C Floating Point Exceptions in C Find Duplicate Elements in Array in C Sum of Diagonal Elements of A Matrix in C File Functions in C Float in C Programming Find Length of Array in C Documentation Section in C Comment Line in C Define Data Structure in C File Modes in C File Opening Modes in C FMOD in C Hallow Diamond Pattern in C Hill Cipher Program in C INT MAX in C Integer Size in C Most Frequently asked C Programming Language Questions for Freshers Passing Pointers to Function in C Passing Strings to Function in C Permutation of String in C Syntax Error in C Top Down Approach in C Types of Strings in C Unconditional Statements in C Auto Keyword in C Characteristics of Algorithm in C Circular Doubly Linked List in C Hamming Code in C Duplicate Array in C Flowchart For While Loop in C Format Specifiers in C Generic Pointer in C Happy Number in C Memory Mapping in C Recursion in C Relational Operators in C Strmcp Return Value in C Non Primitive Data Types in C Octal to Decimal in C Parameter Passing Technique in C Print Magic Square in C Quadratic Equation in C

gets() function in C

gets() is a pre-define or built-in function present in the stdio.h header file. stdio stands for standard input and output. gets() function is used to read a stream and store it in a C string. gets() function read the character until a newline character is entered or enter key is entered, or the end of the file is reached.

If we give the string size 15 and the input character are greater than 20, The gets() function will read 20 characters without checking the maximum limit, but while compiling, we get buffer overflow error.

gets()  function also reads spaces. The array bound is not checked by the gets() function.

gets() function takes a string as the parameter and returns the string if there are no errors. Else, return a null value. No character given in input at the end of file.

Syntax to call gets() function:

gets(input string name);

Example: gets(string1);

Example  program on gets() function:

// program to read and print a string using gets() function.
#include <stdio.h>
int main ()  // main function
{
   char s[50]; // string declaration with size 50.
   printf("Enter a string : ");
   // Reading the string
   gets(s); // function call
   printf("  \nThe string which you have entered : %s", s);
   return(0);
}

Output:

Enter a string : Hello, Welcome to JavaTpoint tutorials and Examples
The string which you have entered : Hello, Welcome to JavaTpoint tutorials and Examples

Working of gets():

If we want to use gets() function first,  include the <stdio.h> header file. Now the program body starts first we declared a string s of size 50.

Next, we gave a printf statement. In the next step, we call the gets function, and it reads the input string till a new line character is entered.

Now the reading part is done, we are printing the input string on the console output screen.

Advantages of gets() function:

  1. gets() function reads multiple characters at a time.
  2. Gets() function accepts spaces in the string.
  3. It takes a single string as a parameter. Ex: gets(str);

Disadvantages of gets() function:

  1. The gets() function reads the input characters until the new line character key is entered.
  2. If the input string exceeds the size of the string we get the buffer overflow error.
  3. We can’t check the bounds of the input array.
  4. gets() function  is not safe.
  5. Size of the string is fixed.

Simple example program to show buffer overflow error message:

// program to show buffer overflow error message.
#include <stdio.h>
int main ()  // main function
{
   char s[10]; // string declaration with size 10
   printf("Enter a string : ");
   // Reading the string
   gets(s); // function call
   printf("  \nThe string which you have entered : %s", s);
   return(0);
}

Output:

Enter a string : Welcome to JavaTpoint
*** stack smashing detected ***: terminated

Aborted

Here the size of the given string is greaterthen the given string. The gets() function reads the input successfully, but while returning, it displays *** stack smashing detected ***: terminated Aborted.

Example program to take input string using gets() function and print the length of the string.

// program to calculate the length of the given string using iteration method.
#include <stdio.h>
#include <string.h>
#define max 100
int main ()  // main function
{
   char s[max]; // string declaration.
   int i, c=0; // initially length of the string c=0
   printf("Enter a string : ");
    // Reading the string
   gets(s); // function call
   printf("  \nThe string you have entered : %s", s);
   for(i=0;s[i]!='\0';i++)
   {
       c++; // incrementing the length of the string for each iteration
   }
   // printing the length of the string.
   printf(" \nThe length of the given string is= %d", c);
   return(0);
}

Output:

Enter a string : Hello, Welcome to JavaTpoint tutorials and examples
The string you have entered : Hello, Welcome to JavaTpoint tutorials and examples 
The length of the given string is= 51

Example program to read the string using gets() function and display the size of the string using strlen() function.

// program to calculate the length of the given string.
#include <stdio.h>
#include <string.h>
#define max 100
int main ()  // main function
{
   char s[max]; // string declaration.
   int a;
   printf("Enter a string : ");
    // Reading the string
   gets(s); // function call
   printf("  \nThe string you have entered : %s", s);
   a = strlen(s); // calculating the string length using strlen() function
   // printing the length of the string.
   printf(" \nThe length of the given string is= %d", a);
   return(0);
}

Output:   

Enter a string : Hello, Welcome to JavaTpoint tutorials and examples
The string you have entered : Hello, Welcome to JavaTpoint tutorials and examples 
The length of the given string is= 51

Conclusion:

In this article, we learned how to use the gets() function, its uses, and the advantages and disadvantages of the gets() function.

Examples of the gets() function are also attached to this article. With the help of examples, we can learn the implementation of gets() function using c, and we can identify in which case we can implement this function.