tcflush(3) — Linux manual page

tcflush(3)               Library Functions Manual              tcflush(3)

NAME         top

       tcflush - discard pending data

LIBRARY         top

       Standard C library (libc, -lc)

SYNOPSIS         top

       #include <termios.h>

       int tcflush(int fd, int queue_selector);

DESCRIPTION         top

       tcflush() discards data written to the object referred to by fd
       but not transmitted, or data received but not read, depending on
       the value of queue_selector:

       TCIFLUSH
              flushes data received but not read.

       TCOFLUSH
              flushes data written but not transmitted.

       TCIOFLUSH
              flushes both data received but not read, and data written
              but not transmitted.

RETURN VALUE         top

       0      on success.

       -1     on failure and set errno to indicate the error.

ATTRIBUTES         top

       For an explanation of the terms used in this section, see
       attributes(7).
       ┌──────────────────────────────────────┬───────────────┬─────────┐
       │ Interface                            │ Attribute     │ Value   │
       ├──────────────────────────────────────┼───────────────┼─────────┤
       │ tcflush()                            │ Thread safety │ MT-Safe │
       └──────────────────────────────────────┴───────────────┴─────────┘

STANDARDS         top

       POSIX.1-2008.

HISTORY         top

       POSIX.1-2001.

SEE ALSO         top

       tcsendbreak(3), tcdrain(3), tcflow(3), termios(7)

COLOPHON         top

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Linux man-pages 6.19            2026-07-02                     tcflush(3)

Pages that refer to this page: FIONREAD(2const),  _exit(3),  tcdrain(3),  tcflow(3),  tcsendbreak(3),  signal-safety(7),  termios(7)

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