Chapter 6

Managing Text-Based Screens with curses

In Chapter 5, you learned how to obtain much finer control over the input of characters and how to provide character output in a terminal-independent way. The problem with using the general terminal interface (GTI, or termios) and manipulating escape sequences with tparm and its related functions is that it requires a lot of lower-level code. For many programs, a higher-level interface is more desirable. We would like to be able to simply draw on the screen and use a library of functions to take care of terminal dependencies automatically.

In this chapter, you’ll learn about just such a library, the curses library. The curses standard is important as a halfway house between simple “line-based” programs and the fully graphical (and generally harder to program) X Window System programs, such as GTK+/GNOME and Qt/KDE. Linux does have the svgalib (Super VGA Library, a low-level graphics library), but that is not a UNIX standard library, so is not generally available in other UNIX-like operating systems. The curses library is used in many full-screen applications as a reasonably easy and terminal-independent way to write full-screen, albeit character-based, programs. It’s almost always easier to write such programs with curses than to use escape sequences directly. curses can also manage the keyboard, providing an easy-to-use, nonblocking character input mode.

You may find that a few of the examples in this chapter don’t always display ...

Get Beginning Linux Programming, 4th Edition now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.