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28 .\" @(#)tcsetattr.3 8.3 (Berkeley) 1/2/94
44 .Nd manipulating the termios structure
50 .Fn cfgetispeed "const struct termios *t"
52 .Fn cfsetispeed "struct termios *t" "speed_t speed"
54 .Fn cfgetospeed "const struct termios *t"
56 .Fn cfsetospeed "struct termios *t" "speed_t speed"
58 .Fn cfsetspeed "struct termios *t" "speed_t speed"
60 .Fn cfmakeraw "struct termios *t"
62 .Fn cfmakesane "struct termios *t"
64 .Fn tcgetattr "int fd" "struct termios *t"
66 .Fn tcsetattr "int fd" "int action" "const struct termios *t"
74 functions are provided for getting and setting the termios structure.
83 functions are provided for getting and setting the baud rate values in
84 the termios structure.
85 The effects of the functions on the terminal as described below
86 do not become effective, nor are all errors detected, until the
89 Certain values for baud rates set in the termios structure and passed to
91 have special meanings.
92 These are discussed in the portion of the manual page that describes the
95 .Sh GETTING AND SETTING THE BAUD RATE
96 The input and output baud rates are found in the termios structure.
99 is typedef'd in the include file
101 The value of the integer corresponds directly to the baud rate being
102 represented, however, the following symbolic values are defined.
120 #ifndef _POSIX_SOURCE
123 #endif /*_POSIX_SOURCE */
128 function returns the input baud rate in the termios structure referenced by
133 function sets the input baud rate in the termios structure referenced by
140 function returns the output baud rate in the termios structure referenced by
145 function sets the output baud rate in the termios structure referenced by
152 function sets both the input and output baud rate in the termios structure
158 Upon successful completion, the functions
164 Otherwise, a value of -1 is returned and the global variable
166 is set to indicate the error.
167 .Sh GETTING AND SETTING THE TERMIOS STATE
168 This section describes the functions that are used to control the general
170 Unless otherwise noted for a specific command, these functions are restricted
171 from use by background processes.
172 Attempts to perform these operations shall cause the process group to be sent
174 If the calling process is blocking or ignoring SIGTTOU signals, the process
175 is allowed to perform the operation and the SIGTTOU signal is not sent.
177 In all the functions, although
179 is an open file descriptor, the functions affect the underlying terminal
180 file, not just the open file description associated with the particular
185 function sets the flags stored in the termios structure to a state disabling
186 all input and output processing, giving a
190 function sets them to a state similar to those of a newly created
192 It should be noted that there is no function to reverse this effect.
193 This is because there are a variety of processing options that could be
194 re-enabled and the correct method is for an application to snapshot the
195 current terminal state using the function
197 setting raw or sane mode with
203 and then using another
205 with the saved state to revert to the previous terminal state.
209 function copies the parameters associated with the terminal referenced
212 in the termios structure referenced by
214 This function is allowed from a background process, however, the terminal
215 attributes may be subsequently changed by a foreground process.
219 function sets the parameters associated with the terminal from the
220 termios structure referenced by
224 argument is created by
226 the following values, as specified in the include file
228 .Bl -tag -width "TCSADRAIN"
230 The change occurs immediately.
232 The change occurs after all output written to
234 has been transmitted to the terminal.
237 should be used when changing parameters that affect output.
239 The change occurs after all output written to
241 has been transmitted to the terminal.
242 Additionally, any input that has been received but not read is discarded.
248 value, the values of the
256 The 0 baud rate is used to terminate the connection.
257 If 0 is specified as the output speed to the function
259 modem control will no longer be asserted on the terminal, disconnecting
262 If zero is specified as the input speed to the function
264 the input baud rate will be set to the same value as that specified by
265 the output baud rate.
269 is unable to make any of the requested changes, it returns -1 and
271 Otherwise, it makes all of the requested changes it can.
272 If the specified input and output baud rates differ and are a combination
273 that is not supported, neither baud rate is changed.
275 Upon successful completion, the functions
281 return -1 and the global variable
283 is set to indicate the error, as follows:
292 was not a valid file descriptor.
296 function was interrupted by a signal.
302 function was not valid, or an attempt was made to change an attribute
303 represented in the termios structure to an unsupported value.
305 The file associated with the
325 functions are expected to be compliant with the
338 function are extensions to the