what is exec() system call in operating system



The exec() family of functions replaces the current process image with a new process image. It loads the program into the current process space and runs it from the entry point.
The exec() family consists of following functions, I have implemented execv() in following C program, you can try rest as an exercise
int execl(const char *path, const char *arg, ...);
int execlp(const char *file, const char *arg, ...);
int execle(const char *path, const char *arg, ...,
                               char * const envp[]);
int execv(const char *path, char *const argv[]);
int execvp(const char *file, char *const argv[]);
int execvpe(const char *file, char *const argv[],
                             char *const envp[]);

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