source: trunk/minix/commands/i386/mtools-3.9.7/tty.c@ 10

#include "sysincludes.h"
#include "mtools.h"

static FILE *tty=NULL;
static int notty=0;     
static int ttyfd=-1;
#ifdef USE_RAWTERM
int     mtools_raw_tty = 1;
#else
int     mtools_raw_tty = 0;
#endif

#ifdef USE_RAWTERM
# if defined TCSANOW && defined HAVE_TCSETATTR
/* we have tcsetattr & tcgetattr. Good */
typedef struct termios Terminal;
#  define stty(a,b)        (void)tcsetattr(a,TCSANOW,b)
#  define gtty(a,b)        (void)tcgetattr(a,b)
#  define USE_TCIFLUSH

# elif defined TCSETS && defined TCGETS
typedef struct termios Terminal;
#  define stty(a,b) (void)ioctl(a,TCSETS,(char *)b)
#  define gtty(a,b) (void)ioctl(a,TCGETS,(char *)b)
#  define USE_TCIFLUSH

# elif defined TCSETA && defined TCGETA
typedef struct termio Terminal;
#  define stty(a,b) (void)ioctl(a,TCSETA,(char *)b)
#  define gtty(a,b) (void)ioctl(a,TCGETA,(char *)b)
#  define USE_TCIFLUSH

# elif defined(HAVE_SGTTY_H) && defined(TIOCSETP) && defined(TIOCGETP)
typedef struct sgttyb Terminal;
#  define stty(a,b) (void)ioctl(a,TIOCSETP,(char *)b)
#  define gtty(a,b) (void)ioctl(a,TIOCGETP,(char *)b)
#  define USE_SGTTY
#  define discard_input(a) /**/

# else
/* no way to use raw terminal */
/*
#  warning Cannot use raw terminal code (disabled)
*/
#  undef USE_RAWTERM
# endif

#endif

#ifdef USE_TCIFLUSH
# if defined TCIFLUSH && defined HAVE_TCFLUSH
#  define discard_input(a) tcflush(a,TCIFLUSH)
# else
#  define discard_input(a) /**/
# endif
#endif

#ifdef USE_RAWTERM

static int tty_mode = -1; /* 1 for raw, 0 for cooked, -1 for initial */
static int need_tty_reset = 0;
static int handlerIsSet = 0;

#define restore_tty(a) stty(STDIN,a)


#define STDIN ttyfd
#define FAIL (-1)
#define DONE 0
static Terminal in_orig;

/*--------------- Signal Handler routines -------------*/

static void tty_time_out(void)
{
        int exit_code;
        signal(SIGALRM, SIG_IGN);
        if(tty && need_tty_reset)
                restore_tty (&in_orig); 
#if future
        if (fail_on_timeout)
                exit_code=SHFAIL;
        else {
                if (default_choice && mode_defined) {
                        if (yes_no) {
                                if ('Y' == default_choice)
                                        exit_code=0;
                                else
                                        exit_code=1;
                        } else
                                exit_code=default_choice-minc+1;
                } else
                        exit_code=DONE;
        }
#else
        exit_code = DONE;
#endif
        exit(exit_code);
}

static void cleanup_tty(void)
{ 
        if(tty && need_tty_reset) {
                restore_tty (&in_orig);
                setup_signal();
        }
}

static void set_raw_tty(int mode)
{
        Terminal in_raw;

        if(mode != tty_mode && mode != -1) {
                if(!handlerIsSet) {
                        /* Determine existing TTY settings */
                        gtty (STDIN, &in_orig);
                        need_tty_reset = 1;

                        /* Restore original TTY settings on exit */
                        atexit(cleanup_tty);
                        handlerIsSet = 1;
                }


                setup_signal();
                signal (SIGALRM, (SIG_CAST) tty_time_out);
        
                /* Change STDIN settings to raw */

                gtty (STDIN, &in_raw);
                if(mode) {
#ifdef USE_SGTTY
                        in_raw.sg_flags |= CBREAK;
#else
                        in_raw.c_lflag &= ~ICANON;
                        in_raw.c_cc[VMIN]=1;
                        in_raw.c_cc[VTIME]=0;                   
#endif
                        stty (STDIN, &in_raw);
                } else {
#ifdef USE_SGTTY
                        in_raw.sg_flags &= ~CBREAK;
#else
                        in_raw.c_lflag |= ICANON;
#endif
                        stty (STDIN, &in_raw);
                }
                tty_mode = mode;
                discard_input(STDIN);
        }
}
#endif

FILE *opentty(int mode)
{
        if(notty)
                return NULL;
        if (tty == NULL) {
                ttyfd = open("/dev/tty", O_RDONLY);
                if(ttyfd >= 0) {
                        tty = fdopen(ttyfd, "r");
                }
        }
        if  (tty == NULL){
                if ( !isatty(0) ){
                        notty = 1;
                        return NULL;
                }
                ttyfd = 0;
                tty = stdin;
        }
#ifdef USE_RAWTERM
        if(mtools_raw_tty)
                set_raw_tty(mode);
#endif
        return tty;
}

int ask_confirmation(const char *format, const char *p1, const char *p2)
{
        char ans[10];

        if(!opentty(-1))
                return 0;

        while (1) {
                fprintf(stderr, format, p1, p2);
                fflush(stderr);
                fflush(opentty(-1));
                if (mtools_raw_tty) {
                        ans[0] = fgetc(opentty(1));
                        fputs("\n", stderr);
                } else {
                        fgets(ans,9, opentty(0));
                }
                if (ans[0] == 'y' || ans[0] == 'Y')
                        return 0;
                if (ans[0] == 'n' || ans[0] == 'N')
                        return -1;
        }
}