/* shkeys.c */

/* compile me: cc -o shkeys shkeys.c */

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>

int main (void)
{
    struct termios oldtio, newtio;
    int rc, rdlen, c, i, leave;
    char buf [12];
    char prbuff [128], *p;

    rc= tcgetattr (0, &oldtio);
    if (rc) {
        perror ("tcgetattr (0, &oldtio)");
	return 4;
    }
    memcpy (&newtio, &oldtio, sizeof (newtio));
    newtio.c_lflag &= ~(ISIG | ICANON | ECHO);
    newtio.c_iflag &= ~(INLCR | ICRNL | IXON | IXOFF);
    newtio.c_cflag &= ~(PARENB);
    newtio.c_cflag = (newtio.c_cflag & ~CSIZE) | CS8;
    newtio.c_cc[VMIN] = 1;
    rc= tcsetattr (0, TCSAFLUSH, &newtio);
    if (rc) {
	perror ("tcsetattr (0, TCSAFLUSH, &newtio)");
	return 12;
    } 

    printf ("Press any key to see codes, ctrl-D to terminate\n\n");

    for (leave= 0; ! leave; ) {
        rdlen= read (0, buf, sizeof (buf));
	if (rdlen<0) {
	    perror ("read(0)");
	    leave= 1; /* error */
	} else if (rdlen==0) {
	    leave= 1; /* EOF */
	} else {
	    p= prbuff;
	    for (i=0; i<rdlen; ++i) {
	        c= (unsigned char)buf[i];
	        if (c < ' ') {
		    p += sprintf (p, "^%c",  c+64);
		} else if (c==0x7f) {
		    p += sprintf (p, "^?");
		} else {
		    p += sprintf (p, "%c", c);
		}
	    }
	    for (i=0; i<rdlen; ++i) {
	        c= (unsigned char)buf[i];
	        printf ("%-16s %3d 0x%02x 0%03o\n", prbuff, c, c, c);
		prbuff[0] = '\0';
	    }
	    if (buf[0]==4) leave= 1; /* ctrl-D */
	}
    }

    rc= tcsetattr (0, TCSAFLUSH, &oldtio);
    if (rc) {
	perror ("tcsetattr (0, TCSAFLUSH, &oldtio)");
	return 12;
    }
    return 0;
}