LINUX | Write C code without main смотреть онлайн

10th Video : Write C code without main ()
Playlist : #Linux #C

® Can a C program be written without main ()?

Yes, you can write a C program without main().

We are taught in almost every book that main () is the entry point of a program execution. It is not completely true. At an abstract level, it is true just from the perspective of programmer. But from systems perspective _start() is the first function that is called. _start() sets up the environment for program execution and then calls main().
You can build code without main using this command:
gcc file_name.c -nostartfiles -o file_name

© How do you came to know that _start is called first then it calls the main()?

Using this command:
• objdump -f file_name
• objdump --disassemble file_name

© Note :
For example u can write a device driver or kernel module in C that interacts with the operating system or hardware. These drivers are loaded by the operating system at boot time and don't need a main() function because they are not user-space programs.


__________________________________________________________
Check out more video!
- #C programming playlist: https://youtube.com/playlist?list=PLwny232duu-AFtSckUxSS1iEQQPJ8aGeR
- #Union in C playlist: https://youtube.com/playlist?list=PLwny232duu-BId6OBxRis3mK8cCVhzmW4
- #GDB playlist: https://youtube.com/playlist?list=PLwny232duu-BiJoPOIEG2GoyZ7d5vcB9a

#software #embeddeddeveloper
#C #C++ #programming
#embeddedsystems #linux