man3p/tcflush.3p

   1 .\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
   2 .TH "TCFLUSH" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
   3 .\" tcflush
   4 .SH NAME
   5 tcflush \- flush non-transmitted output data, non-read input data,
   6 or both
   7 .SH SYNOPSIS
   8 .LP
   9 \fB#include <termios.h>
  10 .br
  11 .sp
  12 int tcflush(int\fP \fIfildes\fP\fB, int\fP \fIqueue_selector\fP\fB);
  13 .br
  14 \fP
  15 .SH DESCRIPTION
  16 .LP
  17 Upon successful completion, \fItcflush\fP() shall discard data written
  18 to the object referred to by \fIfildes\fP (an open file
  19 descriptor associated with a terminal) but not transmitted, or data
  20 received but not read, depending on the value of
  21 \fIqueue_selector\fP:
  22 .IP " *" 3
  23 If \fIqueue_selector\fP is TCIFLUSH, it shall flush data received
  24 but not read.
  25 .LP
  26 .IP " *" 3
  27 If \fIqueue_selector\fP is TCOFLUSH, it shall flush data written but
  28 not transmitted.
  29 .LP
  30 .IP " *" 3
  31 If \fIqueue_selector\fP is TCIOFLUSH, it shall flush both data received
  32 but not read and data written but not transmitted.
  33 .LP
  34 .LP
  35 Attempts to use \fItcflush\fP() from a process which is a member of
  36 a background process group on a \fIfildes\fP associated
  37 with its controlling terminal shall cause the process group to be
  38 sent a SIGTTOU signal. If the calling process is blocking or
  39 ignoring SIGTTOU signals, the process shall be allowed to perform
  40 the operation, and no signal is sent.
  41 .SH RETURN VALUE
  42 .LP
  43 Upon successful completion, 0 shall be returned. Otherwise, -1 shall
  44 be returned and \fIerrno\fP set to indicate the error.
  45 .SH ERRORS
  46 .LP
  47 The \fItcflush\fP() function shall fail if:
  48 .TP 7
  49 .B EBADF
  50 The \fIfildes\fP argument is not a valid file descriptor.
  51 .TP 7
  52 .B EINVAL
  53 The \fIqueue_selector\fP argument is not a supported value.
  54 .TP 7
  55 .B ENOTTY
  56 The file associated with \fIfildes\fP is not a terminal.
  57 .sp
  58 .LP
  59 The \fItcflush\fP() function may fail if:
  60 .TP 7
  61 .B EIO
  62 The process group of the writing process is orphaned, and the writing
  63 process is not ignoring or blocking SIGTTOU.
  64 .sp
  65 .LP
  66 \fIThe following sections are informative.\fP
  67 .SH EXAMPLES
  68 .LP
  69 None.
  70 .SH APPLICATION USAGE
  71 .LP
  72 None.
  73 .SH RATIONALE
  74 .LP
  75 None.
  76 .SH FUTURE DIRECTIONS
  77 .LP
  78 None.
  79 .SH SEE ALSO
  80 .LP
  81 \fItcdrain\fP() , the Base Definitions volume of IEEE\ Std\ 1003.1-2001,
  82 Chapter 11, General Terminal Interface, \fI<termios.h>\fP, \fI<unistd.h>\fP
  83 .SH COPYRIGHT
  84 Portions of this text are reprinted and reproduced in electronic form
  85 from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
  86 -- Portable Operating System Interface (POSIX), The Open Group Base
  87 Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
  88 Electrical and Electronics Engineers, Inc and The Open Group. In the
  89 event of any discrepancy between this version and the original IEEE and
  90 The Open Group Standard, the original IEEE and The Open Group Standard
  91 is the referee document. The original Standard can be obtained online at
  92 http://www.opengroup.org/unix/online.html .