Linux programming learning notes (11) curses Cui Interface

Cui character Interface
Gui: graphical interface

Use a set of encapsulated library libcruses. So
Old Version libcurses. So
New Version libncruses. So
-Lcurses or-lncurses are required during compilation.
If the header file curses. h does not exist, use ncurses. h.

Printf/scanf standard Io
Most standard Io redirection to/dev/tty/det/pts/1

Curses is the terminal output.

To prevent the UI from being redirected to the terminal by printf, do not use printf output.

1 Programming Model

Initialize the terminal window * initscr ();
Returns an initialized form.
Operation terminal (input/output/location/refresh)
Release terminal int endwin ()
2 display

2.1 Graphic Output

Border prints a border
Int border (chtype ls, chtype RS, chtype ts, chtype BS,
Chtype TL, chtype TR, chtype BL, chtype BR );
The eight parameters are the characters in the upper left, lower left, upper right, lower left, and lower right.
You can use 8 zeros to use the default border.
Border ('A', 'B', 'C', 'E', 'F', 'G', 'h', 'G ');
Border (0, 0, 0, 0, 0, 0 );
Wborder draws a border in the specified form

Box prints a border
Int box (window * Win, chtype verch, chtype Horch );
Box requires a form. Only horizontal and vertical border characters can be set.
In addition to returning init_scr (), the standard screen can also use the global variable stdscr.
Box (stdscr,); the effect is the same as border (,);

Hline horizontal line
Hline draws a horizontal line at the cursor position of the standard form
Whline draws a horizontal line at the cursor position of the specified form
Mvhline draws a horizontal line at a specified position in the standard form
Mvwhline draws a horizontal line at the specified form pointer position

Vline vertical line (same as hline)

Attribute character: byte = attribute byte + character byte
Note:
Box requires a form
Initscr returns the initialized form: standard screen
Curses defines a global variable stdscr to represent the standard form.
Naming rules:
*** A function
W *** run a function in a form
MV *** runs a function at a specified position
Mvw ***
Run a function at the specified position in the specified form

2.2 screen Flushing

Void refresh (); // display the output immediately. Generally, refresh is returned immediately after the output.
Void wrefresh (window *);
Screen flushing from the inside out

3-character output

Int addch (const chtype ch );
Int waddch (window * Win, const chtype ch );
Int mvaddch (INT y, int X, const chtype ch );
Int mvwaddch (window * Win, int y, int X, const chtype ch );
Attribute character: ''| attribute
(Character bit budget character attribute)


Attribute (in man attron)
A_normal normal display (no highlight)
A_standout best highlighting mode of the terminal.
A_underline underlining
A_reverse Reverse Video
A_blink blinking
A_dim half bright
A_bold extra bright or bold
A_protect Protected Mode
A_invis invisible or blank Mode
A_altcharset alternate Character Set
A_chartext bit-mask to extract a character
Color_pair (n) color-Pair number n

Special characters
Man addch can also find characters that do not know how to print, such as pi
Acs_pi * Greek pi
Acs_plminus # plus/minus
Acs_plus + plus
Acs_rarrow> arrow pointing right
Acs_rtee + right tee
Acs_s1-Scan Line 1
And so on.

3-character attribute and color

Color Attribute

3.1 determine whether the terminal supports color (currently, terminals generally support color, but can not be determined)

Bool has_colors (void );

3.2 initialize color

Int start_color (void );

3.3 define color pairs

Int init_pair (short pair, short F, short B );
No. foreground color background color
Up to 8 pairs of colors 1-8 are supported
Optional colors:
Color_black
Color_red
Color_green
Color_yellow
Color_blue
Color_magenta purple
Color_cyan cyan
Color_white

If (has_colors () = true)
{
Start_color (); // initialize the color
Init_pair (1, color_red, color_yellow );
Init_pair (2, color_blue, color_white );
Init_pair (3, color_black, color_white );
Bkgd (color_pair (3 ));
}

3.4 use a color pair (macro)

Color_pair (short pair)
Set Character Color in character attributes
Mvaddch (2,10, 'A' | a_underline | color_pair (1 ));
Set background color bkgd Function
Init_pair (3, color_black, color_white );
Bkgd (color_pair (3); // sets the background color.

This set of functions must be used after init_scr

# Include <curses. h>
Int main ()
{
Initscr (); // initialize the form
If (has_colors () = true)
{
Start_color (); // initialize the color
Init_pair (1, color_red, color_yellow); // defines the color pair
Init_pair (2, color_blue, color_cyan );
Init_pair (3, color_black, color_white );
Bkgd (color_pair (3); // sets the background color.
}
Box (stdscr, 0, 0); // output border
Mvaddch (2, 10, 'A' | a_underline | color_pair (1); // output character
Mvaddch (10, 20, 'B' | a_bold | color_pair (1 ));
Mvaddch (10, 21, acs_pi | color_pair (2); // output special characters

Getch ();
Endwin (); // release the form
}

3.5 output string addstr

Int addstr (const char * Str); Output string
Int addnstr (const char * STR, int N); the first n characters of the output string
Int waddstr (window * Win, const char * Str );
Int waddnstr (window * Win, const char * STR, int N );
Int mvaddstr (INT y, int X, const char * Str );
Int mvaddnstr (INT y, int X, const char * STR, int N );
Int mvwaddstr (window * Win, int y, int X, const char * Str );
Int mvwaddnstr (window * Win, int y, int X, const char * STR, int N );

Mvaddstr (, "Hello World"); // output string

3.6 Format String output printw

Int printw (const char * FMT ,...);
Int wprintw (window * Win, const char * FMT ,...);
Int mvprintw (INT y, int X, const char * FMT ,...);
Int mvwprintw (window * Win, int y, int X, const char * FMT ,...);

3.7 set attributes

Attron () Enable attributes
Attroff () Disable attributes

Attron (color_pair (1); // enable attributes
Mvaddstr (, "Hello World"); // output string
Attroff (color_pair (1); // disable attributes

Attron (color_pair (2) | a_underline); // enable two attributes
Mvaddnstr (3,10, "hahahahaha", 3); // control the first few characters of the output string. 3
Attroff (color_pair (2) | a_underline); // close two attributes

Case 1:

/* Write a time display screen initialization cycle display time and refresh and release resources */# include <curses. h> # include <time. h> // localtime # include <unistd. h> // sleepvoid Init (); void drawui (); void bussiness (); void destory (); int main () {Init (); drawui (); bussiness (); destory ();} void Init () {initscr ();} void destory () {endwin ();} void drawui () {box (stdscr, 0, 0);} void bussiness () {time_t tt; struct TM * t; while (1) {TT = time (0); t = localtime (& TT ); mvprintw (lines/2, (Cols-8)/2, "% 02d: % 02d: % 02d", T-> tm_hour, T-> tm_min, t-> tm_sec); refresh (); // be sure to refresh or not show sleep (1 );}}

Case 2:
/*
Logon page
1 Initialization
2. Drawing Interface
Header
Draw user name input area
Drawing Password Input Area
3. Waiting for Input
4. End
*/

# Include <unistd. h> # include <curses. h> # include <string. h> // # include <stdlib. h> void Init (); void drawlogin (); void destory (); int main () {Init (); drawlogin (); destory (); Return 0 ;} void Init () {initscr ();} void drawlogin () {char * Heads = "BSS bussiness support system"; char * user = "User []"; char * Pwd = "PWD []"; box (stdscr, 0, 0); attron (a_bold); mvaddstr (3, (Cols-strlen (heads)/2, heads ); attroff (a_bold); mvhline (4, (Cols-strlen (heads)/2, 0, strlen (heads); mvaddstr (8, (Cols-strlen (User )) /2, user); mvaddstr (10, (Cols-strlen (PWD)/2, PWD);} void destory () {refresh (); getch (); // press one key to launch endwin ();}

4 input

4.1 Character Input

Int getch (void); returns the input character and returns the echo at the cursor. The cursor moves forward.
Int wgetch (window * Win );
Int mvgetch (INT y, int X); returns the input character and displays it in the specified place.

Int mvwgetch (window * Win, int y, int X );

#include <unistd.h>#include <curses.h>#include <string.h>//#include <stdlib.h>void init();void draw();void destory();int main(){init();draw();destory();return 0;}void init(){initscr();}void draw(){char ch;while(1){ch=mvgetch(LINES/2,COLS/2);mvprintw(20,10,"your input is %c(%d)",ch,ch);refresh();}}void destory(){ endwin();}

Some buttons display incorrect results in man getch.
Key_break Break Key
Key_down the four arrow keys...
Key_up
Key_left
Key_right
Key_home Home Key (upward + left arrow)
Key_backspace backspace
Key_f0 function keys; space for 64 keys
Is reserved.

4.2 control functions

Disable noecho (with ECHO by default)
Int noecho (void );

Make the function key valid (the function key is disabled by default)
Int keypad (window * Win, bool BF );


// Output a character and move the character with the direction key

# Include <curses. h> int main () {int CH, x = 5, y = 5; initscr (); noecho (); // prevent echo keypad (stdscr, true ); // make the function key valid mvaddch (Y, X,'s); While (1) {CH = getch (); mvaddch (Y, X ,''); switch (CH) {Case key_up: y --; break; Case key_down: Y ++; break; Case key_left: X --; break; Case key_right: X ++; break ;} if (x <0 | Y <0) {clear ();} mvaddch (Y, X, 'A'); refresh ();} endwin (); return 0 ;}

4.3 clear screen

Int erase (void); // Delete the entire Screen
Int werase (window * Win );
Int clear (void); // Delete the entire Screen
Int wclear (window * Win );
Int clrtobot (void); // Delete to the end of the screen
Int wclrtobot (window * Win );
Int clrtoeol (void); // delete it to the end of the row
Int wclrtoeol (window * Win)

4.4 cursor control

1. Get the cursor position (this is a macro)
Void getsyx (INT y, int X );
Set parameter location
Void setsyx (INT y, int X );
Set whether the cursor is visible
Int curs_set (INT visibility); 0 invisible

4.5 input string

Int getstr (char * Str );
Int getnstr (char * STR, int N );
Int wgetstr (window * Win, char * Str );
Int wgetnstr (window * Win, char * STR, int N );
Int mvgetstr (INT y, int X, char * Str );
Int mvwgetstr (window * Win, int y, int X, char * Str );
Int mvgetnstr (INT y, int X, char * STR, int N );

4.6 format the input string int scanw (char * FMT ,...);
Int wscanw (window * Win, char * FMT ,...);
Int mvscanw (INT y, int X, char * FMT ,...);
Int mvwscanw (window * Win, int y, int X, char * FMT ,...);

#include <unistd.h>#include <curses.h>#include <string.h>//#include <stdlib.h>void init();void draw();void dealInput();void destory();int main(){init();draw();dealInput();destory();return 0;}void init(){initscr();}void draw(){mvaddstr(2,2,"[     ]+[     ]=[      ]");}void dealInput(){int a,b,ch;while(1){mvaddstr(2,3,"     ");mvaddstr(2,11,"     ");mvaddstr(2,19,"     ");mvscanw(2,3,"%d",&a);mvscanw(2,11,"%d",&b);mvprintw(2,19,"%d",a+b);refresh();mvaddstr(3,3,"is continue? (y/n)");ch = getch();if(ch == 'n'){break;}}}void destory(){ endwin();}

5 windows

For good looks
Subwin (); // create a subform (coordinates of the subform are used)
Derwin (); // create a child form (coordinates of the parent form are used)

Window * Derwin (window * orig, int nlines, int ncols,
Int begin_y, int begin_x );

#include <curses.h>int main(){initscr();WINDOW *w;box(stdscr,0,0);w=derwin(stdscr,10,20,2,2);box(w,0,0);refresh();getch();endwin();}

1. Set encoding in VI
: Set enconding = encoding gd2312 UTF-8 ios-8859-1
2. Specify the source file encoding in the compiler-finput-charset = gb2312
3. Specify the encoding on the terminal
4. Default System Encoding