exec

The exec command is a system call and command-line utility in Unix-like operating systems that replaces the current process with a new program, effectively terminating the original process and executing the specified command in its place. It is commonly used in shell scripting and system programming to run external programs or change the execution context of a process. Unlike fork-based execution, exec does not create a new process but overlays the current one with the new program's code and data.

Also known as: exec command, exec system call, exec(), exec family, execve

Why learn exec?

Developers should learn and use exec when they need to execute external programs from within their applications or scripts without spawning child processes, which is useful for process management, system administration tasks, and building lightweight scripts. Specific use cases include replacing a shell with another program, implementing command execution in system daemons, and optimizing resource usage in embedded systems where forking might be too costly.

Learning Resources

• docs: Linux man page for exec
• tutorial: GeeksforGeeks: exec family of functions in C
• book: Advanced Linux Programming: Process Management
• video: YouTube: exec() system call explained
• docs: The Linux Programming Interface: Chapter 27 (Executing Programs)