1TCFLOW(3P) POSIX Programmer's Manual TCFLOW(3P)
2
6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
10
13 tcflow — suspend or restart the transmission or reception of data
14
16 #include <termios.h>
17 int tcflow(int fildes, int action);
19
21 The tcflow() function shall suspend or restart transmission or recep‐
22 tion of data on the object referred to by fildes, depending on the
23 value of action. The fildes argument is an open file descriptor asso‐
24 ciated with a terminal.
25 * If action is TCOOFF, output shall be suspended.
27 * If action is TCOON, suspended output shall be restarted.
29 * If action is TCIOFF and fildes refers to a terminal device, the
31 system shall transmit a STOP character, which is intended to cause
32 the terminal device to stop transmitting data to the system. If
33 fildes is associated with a pseudo-terminal, the STOP character
34 need not be transmitted.
35 * If action is TCION and fildes refers to a terminal device, the sys‐
37 tem shall transmit a START character, which is intended to cause
38 the terminal device to start transmitting data to the system. If
39 fildes is associated with a pseudo-terminal, the START character
40 need not be transmitted.
41 The default on the opening of a terminal file is that neither its input
43 nor its output are suspended.
44 Attempts to use tcflow() from a process which is a member of a back‐
46 ground process group on a fildes associated with its controlling termi‐
47 nal, shall cause the process group to be sent a SIGTTOU signal. If the
48 calling thread is blocking SIGTTOU signals or the process is ignoring
49 SIGTTOU signals, the process shall be allowed to perform the operation,
50 and no signal is sent.
51
53 Upon successful completion, 0 shall be returned. Otherwise, −1 shall be
54 returned and errno set to indicate the error.
55
57 The tcflow() function shall fail if:
58 EBADF The fildes argument is not a valid file descriptor.
60 EINVAL The action argument is not a supported value.
62 EIO The process group of the writing process is orphaned, the call‐
64 ing thread is not blocking SIGTTOU, and the process is not
65 ignoring SIGTTOU.
66 ENOTTY The file associated with fildes is not a terminal.
68 The following sections are informative.
70
72 None.
73
75 None.
76
78 None.
79
81 None.
82
84 tcsendbreak()
85 The Base Definitions volume of POSIX.1‐2008, Chapter 11, General Termi‐
87 nal Interface, <termios.h>
88
90 Portions of this text are reprinted and reproduced in electronic form
91 from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
92 -- Portable Operating System Interface (POSIX), The Open Group Base
93 Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
94 cal and Electronics Engineers, Inc and The Open Group. (This is
95 POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
96 event of any discrepancy between this version and the original IEEE and
97 The Open Group Standard, the original IEEE and The Open Group Standard
98 is the referee document. The original Standard can be obtained online
99 at http://www.unix.org/online.html .
100 Any typographical or formatting errors that appear in this page are
102 most likely to have been introduced during the conversion of the source
103 files to man page format. To report such errors, see https://www.ker‐
104 nel.org/doc/man-pages/reporting_bugs.html .
105IEEE/The Open Group 2013 TCFLOW(3P)