Linker and the Loader

When you are coding in a programming language, there are two primary functions that your code needs to perform – linking and loading. The linker is responsible for taking all of the separate object files and combining them into a single executable file. The loader is responsible for loading that executable file into memory and running it. In this blog post, we will discuss the difference between the linker and the loader, and how they work together to create a functioning program.

What is Linker?

A linker is a computer program that joins one or more object files generated by a compiler into a single executable, library, or object file. A linker can take objects from a library as input, relink an executable, etc.

The linker resolves references to symbols in the object files. If an object file refers to a symbol that is not defined in that object file, the linker will attempt to find the definition of the symbol in other object files that were combined with the first. If the symbol is not found, the linker will generate an error.

Types of Linker:

There are two types of linkers:

– Static Linker: A static linker links object files into a single executable file. The resulting executable file is self-contained and does not require any additional object files to run.

– Dynamic Linker: A dynamic linker links object files into a shared library. The resulting shared library can be used by any number of executable files that link to it.

What is a loader?

Loader is system software that handles the loading of programs and libraries. It takes care of allocating memory to the program, linking it with libraries, and loading it into memory. Loader is usually the first program that starts when you turn on your computer.

Types of Loader:

There are two types of Loader. We have discussed both of them in the following sections.

1.Static Loader: The static loader loads the program into memory and resolves all symbol references. It is simple and does not require much memory.

2.Dynamic Loader: The dynamic loader resolves symbol references when the program is loaded into memory. This allows programs to be loaded on demand, which reduces the memory footprint of the system.

What is the difference between linker and loader?

The difference between loader and linker can be divided on a different basis of the definition, base, input, function, type and uses.

Definition:

A linker is a computer program that joins one or more object files generated by a compiler into a single executable, library, or other object files.

A loader is a computer program that loads an executable file into memory, prepares it for execution, and starts its execution.

Base:

The difference between the loader and the linker is that a loader loads an executable file into memory, while a linker combines object files.

Input:

A loader usually takes an input of an executable file, while a linker usually takes in one or more object files.

Function:

The difference between the loader and the linker is that a loader loads an executable file into memory, while a linker combines object files. This means that a loader is responsible for loading a program into memory and making it ready to be executed, while a linker is responsible for taking the object files generated by the compiler and combining them into an executable file.

Type:

A linker is a computer program, while a loader is usually a system program.

Uses:

A loader is used to load an executable file into memory, while a linker is used to combine object files.

The difference between the loader and the linker can be summarized as:

– A loader loads an executable file into memory, while a linker combines object files

– A loader usually takes an input of an executable file, while a linker usually takes in one or more object files

– The difference between the loader and linker is that a loader loads an executable file into memory, while a linker combines object files

– A linker is a computer program, while a loader is usually a system program

Conclusion

So, what is the difference between the linker and loader? The loader is responsible for loading an executable program into memory and starting it. The linker takes object files created by a compiler and combines them into an executable program. It also adds information to the executable file so that the runtime system knows where to find libraries and other related files. When you run a program, your computer first looks for an executable file with the correct name and extension. If it finds it, it loads and runs the program. If not, it displays an error message telling you how to fix the problem.