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28 .\" @(#)tcsetattr.3 8.3 (Berkeley) 1/2/94
43 .Nd manipulating the termios structure
49 .Fn cfgetispeed "const struct termios *t"
51 .Fn cfsetispeed "struct termios *t" "speed_t speed"
53 .Fn cfgetospeed "const struct termios *t"
55 .Fn cfsetospeed "struct termios *t" "speed_t speed"
57 .Fn cfsetspeed "struct termios *t" "speed_t speed"
59 .Fn cfmakeraw "struct termios *t"
61 .Fn tcgetattr "int fd" "struct termios *t"
63 .Fn tcsetattr "int fd" "int action" "const struct termios *t"
70 functions are provided for getting and setting the termios structure.
79 functions are provided for getting and setting the baud rate values in
80 the termios structure.
81 The effects of the functions on the terminal as described below
82 do not become effective, nor are all errors detected, until the
85 Certain values for baud rates set in the termios structure and passed to
87 have special meanings.
88 These are discussed in the portion of the manual page that describes the
91 .Sh GETTING AND SETTING THE BAUD RATE
92 The input and output baud rates are found in the termios structure.
95 is typedef'd in the include file
97 The value of the integer corresponds directly to the baud rate being
98 represented, however, the following symbolic values are defined.
116 #ifndef _POSIX_SOURCE
119 #endif /*_POSIX_SOURCE */
124 function returns the input baud rate in the termios structure referenced by
129 function sets the input baud rate in the termios structure referenced by
136 function returns the output baud rate in the termios structure referenced by
141 function sets the output baud rate in the termios structure referenced by
148 function sets both the input and output baud rate in the termios structure
154 Upon successful completion, the functions
160 Otherwise, a value of -1 is returned and the global variable
162 is set to indicate the error.
163 .Sh GETTING AND SETTING THE TERMIOS STATE
164 This section describes the functions that are used to control the general
166 Unless otherwise noted for a specific command, these functions are restricted
167 from use by background processes.
168 Attempts to perform these operations shall cause the process group to be sent
170 If the calling process is blocking or ignoring SIGTTOU signals, the process
171 is allowed to perform the operation and the SIGTTOU signal is not sent.
173 In all the functions, although
175 is an open file descriptor, the functions affect the underlying terminal
176 file, not just the open file description associated with the particular
181 function sets the flags stored in the termios structure to a state disabling
182 all input and output processing, giving a
184 It should be noted that there is no function to reverse this effect.
185 This is because there are a variety of processing options that could be
186 re-enabled and the correct method is for an application to snapshot the
187 current terminal state using the function
189 setting raw mode with
193 and then using another
195 with the saved state to revert to the previous terminal state.
199 function copies the parameters associated with the terminal referenced
202 in the termios structure referenced by
204 This function is allowed from a background process, however, the terminal
205 attributes may be subsequently changed by a foreground process.
209 function sets the parameters associated with the terminal from the
210 termios structure referenced by
214 argument is created by
216 the following values, as specified in the include file
218 .Bl -tag -width "TCSADRAIN"
220 The change occurs immediately.
222 The change occurs after all output written to
224 has been transmitted to the terminal.
227 should be used when changing parameters that affect output.
229 The change occurs after all output written to
231 has been transmitted to the terminal.
232 Additionally, any input that has been received but not read is discarded.
238 value, the values of the
246 The 0 baud rate is used to terminate the connection.
247 If 0 is specified as the output speed to the function
249 modem control will no longer be asserted on the terminal, disconnecting
252 If zero is specified as the input speed to the function
254 the input baud rate will be set to the same value as that specified by
255 the output baud rate.
259 is unable to make any of the requested changes, it returns -1 and
261 Otherwise, it makes all of the requested changes it can.
262 If the specified input and output baud rates differ and are a combination
263 that is not supported, neither baud rate is changed.
265 Upon successful completion, the functions
271 return -1 and the global variable
273 is set to indicate the error, as follows:
282 was not a valid file descriptor.
286 function was interrupted by a signal.
292 function was not valid, or an attempt was made to change an attribute
293 represented in the termios structure to an unsupported value.
295 The file associated with the
315 functions are expected to be compliant with the
327 function are extensions to the