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

What are linker and loader in C
2022-08-25 19:19:26

What are linker and loader in C

Linker and loader are utility programs that have a significant role in executing a program.

Linker: A linker is a program that joins the object files produced by the assembler/ compiler and other blocks of code to generate an executable file with a .exe extension. Linker has the functionality to search and add all the libraries needed for the executable file. The main aim of the linker is to produce executable files.

The linker controls the memory for the blocks of code and builds a link between different object programs. It organizes the objects in the memory space.

What does a linker do?

The compiler produces the object code of a program, and the code is passed onto the linker. The linker generates the executable code using the code obtained from the assembler/compiler. The executable code then passes to the loader.

Many large programs are split into sub-programs. These sub-programs are known as modules. When the modules are compiled, and object code is generated. The object codes from all these sub-programs are combined and form a single executable file of the main program.

There are two types of linkers

  1. Linkage Editor
  2. Dynamic

Linkage Editor: This linker helps in producing relocatable (portable) executable modules. The linking done by the linkage editor is known as static linking. The linkage by a linkage editor is made during program compilation. Static linking helps relocate code and modifies symbol references to the relocated memory location. Every symbol has a specific task.

Dynamic Linker: This linker delays the linkage of modules from an outside source(external modules) until an executable module is generated. The linking is done during run-time.

The linking by the dynamic linker is referred to as dynamic linking, performed during run time. It is based on the memory sharing concept. The linking is achieved by allocating space for the shareable libraries in the executable image.

What is a Loader?

A loader is a unit of an operating system that loads programs and libraries. It takes executable files produced from the linker as an input. The main objective of loader is to load the executable files into the main memory. It also helps in assigning addresses to the executable files. The embedded computer system executes the code through ROM.

The loader has an essential role in the execution of the program. It reads the executable file and stores the instructions which help the executable file to run.

What does a loader do?

The loader initiates the registers, and the validation of the program is done for memory permissions, etc. It loads the files with the required libraries from the disk into the memory. Executable files are executed when the loader loads them into the memory.

There are three types of loading:

  1. Absolute loading
  2. Relocatable loading
  3. Dynamic run-time loading

Absolute loading: All the executable files are assigned the same memory location in this loading. The programmer should know the assignment strategy for loading the modules.

Relocatable loading: Relative addresses are produced by the compiler instead of the main memory address.

Dynamic Run-Time loading: This loading generates the address when the executable module is run. A different main memory address is given when the executing module is interrupted, removed from the disk, and loaded again.

Differences between Linker and Loader

Description LoaderLinker
DefinitionIt takes object files from the compiler /assembler and generates executable files by joining them.It loads executable files into the main program.
InputObject code is taken as input from the compiler/assembler.Executable files are taken as input from the linker.
FunctionLinks the object and header files to get executable files.The address is assigned in the main memory for the executable modules.
TypesDynamic linker and linker editor are the types of linkers.Relocatable loading, Absolute loading, and Dynamic Run-time loading.
Roleorganizing objects in the address space.Adjusting references that are used in the program.

Representation of linker and loader

What are linker and loader in C

Conclusion

The linker is used to generate executable files by taking object modules from the compiler/assembler. The linker links the other library functions in the object module to the built-in libraries. The loader loads the executable modules into the main memory for executing the program.