Input and Output

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Input and Output

ncurses has many functions for sending output to and receiving input from screens and windows.
It is important to understand that C's standard input and output routines do not work with ncurses' windows. Fortunately, ncurses' I/O routines behave very similarly to the standard I/O () routines, so the learning curve is tolerably shallow.
Output Routines,
- character routines,
- string routines,
- miscellaneous routines.
The http://siber.cankaya.edu.tr/SystemsProgramming/cfiles/curschar.c program in Fig. 12.6 illustrates ncurses' character output functions. Compile with
```
$ gcc -c utilfcns.c
$ gcc -o curschar curschar.c -lcurses utilfcns.o
```
Figure 12.6: Illustrates ncurses' character output functions.
$\begin{figure}\begin{center} \small \begin{verbatim}...$
The http://siber.cankaya.edu.tr/SystemsProgramming/cfiles/cursstr.c program in Fig. 12.7 demonstrates using the string output functions.

Figure 12.7: Demonstrates using the string output functions.
$\begin{figure}\begin{center} \small \begin{verbatim}...$
The http://siber.cankaya.edu.tr/SystemsProgramming/cfiles/cursbox.c program in Fig. 12.8 illustrates using line graphics characters and also the box() and wborder() calls.

Figure 12.8: Illustrates using line graphics characters.
$\begin{figure}\begin{center} \small \begin{verbatim}...$
The http://siber.cankaya.edu.tr/SystemsProgramming/cfiles/cursinch.c program and also other http://siber.cankaya.edu.tr/SystemsProgramming/cfiles/cursgstr.c program in Fig. 12.9 illustrates the usage of the input routines getch, getstr, and scanw.

Figure 12.9: Illustrates the usage of the input routines.
$\begin{figure}\begin{center} \scriptsize \begin{verbatim}...$
Color Routines;
- we have already seen that ncurses supports various highlighting modes. Interestingly, it also supports color in the same fashion.
- before you use ncurses' color capabilities, you have to make sure that the current terminal supports color. The has_colors() call returns TRUE or FALSE depending on whether or not the current terminal has color capabilities.
- The http://siber.cankaya.edu.tr/SystemsProgramming/cfiles/color.c program in Fig. 12.10 illustrates basic color usage. It must be run on a terminal emulator that supports color, such as a color xterm.
  
  Figure 12.10: Illustrates basic color usage.
  $\begin{figure}\begin{center} \scriptsize \begin{verbatim}...$
- The http://siber.cankaya.edu.tr/SystemsProgramming/cfiles/cursutil.c program in Fig. 12.11 illustrates using some of the utility functions.
  
  Figure 12.11: Illustrates the usage of the some utility functions.
  $\begin{figure}\begin{center} \scriptsize \begin{verbatim}...$
ncurses is both an easier and more powerful interface for manipulating the display than termios. ncurses is a ubiquitous library, used in popular programs such as the mutt mail client, the Midnight Commander file manager, lynx, ncftp, and nvi.

**Figure 12.6:** Illustrates ncurses' character output functions.
$\begin{figure}\begin{center} \small \begin{verbatim}...$

**Figure 12.7:** Demonstrates using the string output functions.
$\begin{figure}\begin{center} \small \begin{verbatim}...$

**Figure 12.8:** Illustrates using line graphics characters.
$\begin{figure}\begin{center} \small \begin{verbatim}...$

**Figure 12.9:** Illustrates the usage of the input routines.
$\begin{figure}\begin{center} \scriptsize \begin{verbatim}...$

**Figure 12.10:** Illustrates basic color usage.
$\begin{figure}\begin{center} \scriptsize \begin{verbatim}...$

**Figure 12.11:** Illustrates the usage of the some utility functions.
$\begin{figure}\begin{center} \scriptsize \begin{verbatim}...$

Next: X Window Programming Up: Screen Manipulation with ncurses Previous: Illustrating ncurses Initialization and Contents

Cem Ozdogan 2007-05-16