ft_select

ft_select is an interactive terminal program developed in C as part of the 42 School curriculum. This project involves building a custom user interface in a raw terminal environment, allowing users to navigate and select items passed via the command line. It explores low-level terminal handling using the termcap library and system calls that give fine-grained control over terminal behavior.

Project Overview

• Language: C
• Executable: ft_select
• Objective: Create a responsive text-based interface that processes real-time input and adapts to terminal constraints.
• Core Topics:
  • Terminal configuration using termios
  • Terminal display control via termcap
  • Input capture in non-canonical mode (e.g., arrows, esc, fn keys)
  • Signal handling and cleanup
  • Low-level I/O and memory safety
• Original task
• Original task (fr)

Goals

This project introduces the concepts of terminal control beyond basic input/output. You will learn:

• How terminals buffer and manage input under normal circumstances
• How to disable canonical mode and echo to handle raw input directly
• How to capture complex keys like arrow keys and escape sequences
• How to write an application that redraws its UI responsively and exits cleanly
• How to handle UNIX signals (e.g., SIGWINCH, SIGTSTP, SIGCONT)
• Why terminal programming is powerful but non-trivial

Features

• Interactive Item Selection: Navigate a list of arguments and select them using the keyboard
• Keyboard Support: Arrow keys, space, tab, enter, esc
• Responsive UI: Automatically adjusts to window resizing
• Signal Support: Suspend/resume behavior with correct redraw
• Memory-Safe: No leaks, stable exit, proper cleanup

Usage

$ make
$ ./ft_select item1 item2 item3 ...

Controls

Key	Action
Up / Down Arrow	Move selection cursor
Space / Tab	Toggle item selection
Enter	Confirm and print selection
Esc / Ctrl-C	Exit without selection

Compilation

make

Makefile Targets

Target	Description
all	Build the ft_select binary
clean	Remove object files
fclean	Remove object files and binary
re	Rebuild the project from scratch

Constraints

• Must use termcap (ncurse is forbidden)
• Only specified libc/system functions allowed (e.g., tcgetattr, tputs, ioctl, read)
• No global variables (except for signal handling)
• No crashes or memory leaks
• Must restore terminal to original state upon exit

License

This project is developed for educational purposes as part of the 42 School program.