Visualizza wikitesto di Individuare i tasti premuti della tastiera mediante le risorse esterne delle librerie ioctl.h e termio.h

Utilizzando alcune risorse esterne dichiarate nei file header "''/sys/ioctl.h''" e "''/usr/include/termio.h''" e contenute nella libreria dinamica condivisa di C, è possibile intercettare ed individuare i tasti della tastiera premuti.

E' necessario richiamare in Gambas la libreria condivisa: "''libc.so.6'' ".

Mostriamo un esempio pratico:
 Private Const STDINFD As Integer = 0
 
 
 Library "libc:6"
 
 Public Struct termio
   c_iflag As Short
   c_oflag As Short
   c_cflag As Short
   c_lflag As Short
   c_line As Byte
   c_cc[8] As Byte
 End Struct
 
 Private Const TCGETA As Integer = 21509
 Private Const TCSETA As Integer = 21510
 Private Const ICANON As Integer = 2
 Private Const ECHO As Integer = 16
 
 <FONT Color=gray>' ''int ioctl (int __fd, unsigned long int __request, ...)''
 ' ''Perform the I/O control operation specified by REQUEST on FD.''</font>
 Private Extern ioctl(__fd As Integer, __request As Integer, ter As Termio) As Integer
 
 
 '''Public''' Sub Main()
 
   Dim c As Byte
   Dim param_ant As New Termio
   Dim params As Termio
   Dim fl As File
  
   Print "Premere un tasto..."
   
   ioctl(STDINFD, TCGETA, param_ant)
    
   params = param_ant
   params.c_lflag = params.c_lflag And Not (ICANON Or ECHO)
    
   params.c_cc[4] = 1
    
   ioctl(STDINFD, TCSETA, params)
   
   fl = Open "/proc/self/fd/0"
   Read #fl, c
   fl.Close
   
   ioctl(STDINFD, TCSETA, param_ant)
    
   Print "\rNumero del codice ASCII del tasto premuto: "; c; "  Carattere: "; Chr(c)
   
 '''End'''



=Riferimenti=
* http://man7.org/linux/man-pages/man2/ioctl.2.html