_sys_read.c 724 B

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  1. /* $Source$
  2. * $State$
  3. * $Revision$
  4. */
  5. #include <stdlib.h>
  6. #include <errno.h>
  7. #include <sgtty.h>
  8. #include "libsys.h"
  9. extern struct
  10. {
  11. int fd;
  12. char* buffer;
  13. size_t count;
  14. } _sys_params_in;
  15. extern struct
  16. {
  17. size_t bytesread;
  18. } _sys_params_out;
  19. #define P _sys_params_in
  20. int _sys_read(void)
  21. {
  22. char i;
  23. /* We're only allowed to read from fd 0, 1 or 2. */
  24. if ((P.fd < 0) || (P.fd > 2))
  25. return EBADF;
  26. /* Empty buffer? */
  27. if (P.count == 0)
  28. {
  29. _sys_params_out.bytesread = 0;
  30. return 0;
  31. }
  32. /* Read one byte. */
  33. i = _sys_rawread();
  34. if ((i == '\r') && !(_sys_ttyflags & RAW))
  35. i = '\n';
  36. if (_sys_ttyflags & ECHO)
  37. _sys_write_tty(i);
  38. *P.buffer = i;
  39. _sys_params_out.bytesread = 1;
  40. return 0;
  41. }