ft_script - Educational Implementation of Unix script Command

The script command makes a typescript of everything displayed on your terminal. This implementation demonstrates:

Command-Line Options

Usage: ft_script [options] [file]

Options:
  -a              Append to output file instead of overwriting
  -c <command>    Execute command instead of interactive shell
  -q              Quiet mode (suppress start/done messages)
  -e              Return exit status of child process
  -f              Flush output after each write (BONUS)
  -h              Display help and exit

Implementation Details

1. Fork: Creates child process
2. Setsid: Child creates new session (becomes session leader)
3. Open slave: PTY slave becomes controlling terminal
4. Redirect I/O: stdin/stdout/stderr → PTY slave
5. Exec shell: Replace process image with shell

I/O Multiplexing

Uses select() to monitor multiple file descriptors:

• stdin → Read user input → Write to PTY master
• PTY master → Read child output → Write to stdout and file

References

• man 1 script - Script command manual
• man 2 syscalls - Linux system calls
• man 3 posix_openpt - PTY creation
• man 2 select - I/O multiplexing
• man 3 termios - Terminal attributes