From: "pei lin" <telent998@gmail.com>
To: linux-console@vger.kernel.org
Cc: linux-assembly@vger.kernel.org
Subject: questions about linux termios
Date: Mon, 14 Jul 2008 23:08:11 +0800 [thread overview]
Message-ID: <d6b7c4190807140808p718c7ea9je4269e2f64304d04@mail.gmail.com> (raw)
Hi,buddy
I am puzzled by the linux termios.
First Question about /dev/tty0 and /dev/tty,this two devices is
the same one?
When i am in X terminal,as /dev/pts/0 , i do "echo hello >
/dev/pts/0 and echo hello > /dev/tty ", they return the same like that
"hello" on the screen .This means /dev/tty ->/dev/pts/0? But "echo
hello > /dev/tty0",there is nothing on the screen.And when i go to
Init 3 mode ,like /dev/tty1,when i do "echo hello > /dev/tty1 and echo
hello > .dev/tty and echo hello > /dev/tty0" ,They return the same all
print hello on the screen.Do they all point to the /dev/tty1?
The second Question is that i write a small program to get
keyboard input like below.When i run it in X terminal ,when i press
keyboard it can return but can not get the press and release event.And
in the console,like tty1,it doesn't work .i don't know why.
file : get_keyboard.c
#include <stdio.h>
#include <linux/keyboard.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <linux/kd.h>
#include <termios.h>
#include <unistd.h>
int main()
{
int fd,len,i;
struct kbentry entry;
unsigned char buf[64];
struct termios ts,old_ts;
char * path;
path = ttyname(0);
printf("%s!\n",path);
fd = open(path, O_RDONLY|O_NOCTTY);
if(fd < 0){
printf("open the device error!\n");
}
printf("fd --- %d!\n",fd);
if (ioctl( fd, KDSKBMODE, K_RAW ) < 0) {
printf("set mode wrong!\n");
}
tcgetattr( fd, &old_ts );
ts = old_ts;
ts.c_cc[VTIME] = 0;
ts.c_cc[VMIN] = 1;
ts.c_lflag &= ~(ICANON|ECHO|ISIG);
ts.c_iflag = 0;
tcsetattr( fd, TCSAFLUSH, &ts );
tcsetpgrp( fd, getpgrp() );
entry.kb_table = K_NORMTAB;
entry.kb_value = 0;
while(1){
len=read(fd,buf,64);
printf("len ========= %d!\n",len);
for(i =0; i < len;i++){
entry.kb_index = buf[i];
if(ioctl(fd,KDGKBENT,&entry)){
printf("struct entry :%d %d
%d\n",entry.kb_table,entry.kb_index,entry.kb_value);
if('2' == entry.kb_index){
tcsetattr( fd, TCSAFLUSH, &old_ts );
exit(0);
}
}
}
}
}
next reply other threads:[~2008-07-14 15:08 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-07-14 15:08 pei lin [this message]
2008-07-14 18:38 ` questions about linux termios Frederic Marmond
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