newlib/libc/sys/sysvi386/tcline.c

   1 #define _NO_MACROS
   2 #include <sys/unistd.h>
   3 #include <sys/termios.h>
   4 #include <errno.h>
   5
   6 int
   7 tcsendbreak (int fd, int dur) {
   8         do {
   9                 if (_ioctl (fd, _TCSBRK, 0) == -1)
  10                         return -1;
  11         } while (dur--);
  12         return 0;
  13 }
  14
  15 int
  16 tcdrain (int fd) {
  17         return _ioctl (fd, _TCSBRK, 1);
  18 }
  19
  20 int
  21 tcflush(int fd, int what) {
  22         return _ioctl (fd, _TCFLSH, what);
  23 }
  24
  25 /*
  26  * I'm not positive about this function.  I *think* it's right,
  27  * but I could be missing something.
  28  */
  29
  30 int
  31 tcflow (int fd, int action) {
  32         struct termios t;
  33
  34         switch (action) {
  35         case TCOOFF:
  36         case TCOON:
  37                 return _ioctl (fd, _TCXONC, action);
  38 /*
  39  * Here is where I'm not terribly certain.  1003.1 says:
  40  * if action is TCIOFF, the system shall transmit a STOP
  41  * character, which is intended to cause the terminal device
  42  * to stop transmitting data to the system.  (Similarly for
  43  * TCION.)
  44  * I *assume* that means I find out what VSTOP for the
  45  * terminal device is, and then write it.  1003.1 also does
  46  * not say what happens if c_cc[VSTOP] is _POSIX_VDISABLE;
  47  * I assume it should reaturn EINVAL, so that's what I do.
  48  * Anyway, here's the code.  It might or might not be right.
  49  */
  50         case TCIOFF:
  51                 if (tcgetattr (fd, &t) == -1)
  52                         return -1;
  53                 if (tcgetattr (fd, &t) == -1)
  54                         return -1;
  55 #ifdef _POSIX_VDISABLE
  56                 if (t.c_cc[VSTOP] == _POSIX_VDISABLE) {
  57                         errno = EINVAL;
  58                         return -1;
  59                 }
  60 #endif
  61                 if (write (fd, &t.c_cc[VSTOP], 1) == 1)
  62                         return 0;
  63                 else
  64                         return -1;
  65         case TCION:
  66                 if (tcgetattr (fd, &t) == -1)
  67                         return -1;
  68                 if (tcgetattr (fd, &t) == -1)
  69                         return -1;
  70 #ifdef _POSIX_VDISABLE
  71                 if (t.c_cc[VSTART] == _POSIX_VDISABLE) {
  72                         errno = EINVAL;
  73                         return -1;
  74                 }
  75 #endif
  76                 if (write (fd, &t.c_cc[VSTART], 1) == 1)
  77                         return 0;
  78                 else
  79                         return -1;
  80         default:
  81                 errno = EINVAL;
  82                 return -1;
  83         }
  84 }