1tcflow(3C)               Standard C Library Functions               tcflow(3C)
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NAME

6       tcflow - suspend or restart the transmission or reception of data
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SYNOPSIS

9       #include <termios.h>
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11       int tcflow(int fildes, int action);
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DESCRIPTION

15       The tcflow() function suspends transmission or reception of data on the
16       object referred to by fildes, depending on the  value  of  action.  The
17       fildes argument is an open file descriptor associated with a terminal.
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19           o      If action is TCOOFF, output is suspended.
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21           o      If action is TCOON, suspended output is restarted.
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23           o      If  action is TCIOFF, the system transmits a STOP character,
24                  which is intended to  cause  the  terminal  device  to  stop
25                  transmitting data to the system.
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27           o      If  action is TCION, the system transmits a START character,
28                  which is intended to cause  the  terminal  device  to  start
29                  transmitting data to the system.
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32       The default on the opening of a terminal file is that neither its input
33       nor its output are suspended.
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36       Attempts to use tcflow() from a process which is a member  of  a  back‐
37       ground process group on a fildes associated with its controlling termi‐
38       nal, will cause the process group to be sent a SIGTTOU signal.  If  the
39       calling process is blocking or ignoring SIGTTOU signals, the process is
40       allowed to perform the operation, and no signal is sent.
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RETURN VALUES

43       Upon successful completion, 0 is returned. Otherwise,  −1  is  returned
44       and errno is set to indicate the error.
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ERRORS

47       The tcflow() function will fail if:
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49       EBADF     The fildes argument is not a valid file descriptor.
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52       EINVAL    The action argument is not a supported value.
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55       ENOTTY    The file associated with fildes is not a terminal.
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59       The tcflow() function may fail if:
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61       EIO    The  process  group  of the writing process is orphaned, and the
62              writing process is not ignoring or blocking SIGTTOU.
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ATTRIBUTES

66       See attributes(5) for descriptions of the following attributes:
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71       ┌─────────────────────────────┬───────────────────────────────┐
72       │      ATTRIBUTE TYPE         │       ATTRIBUTE VALUE         │
73       ├─────────────────────────────┼───────────────────────────────┤
74       │Interface Stability          │Standard                       │
75       ├─────────────────────────────┼───────────────────────────────┤
76       │MT-Level                     │MT-Safe, and Async-Signal-Safe │
77       └─────────────────────────────┴───────────────────────────────┘
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SEE ALSO

80       tcsendbreak(3C), attributes(5), standards(5), termio(7I)
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84SunOS 5.11                        14 Aug 2002                       tcflow(3C)
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