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diff --git a/usr/src/man/man4i/termio.4i b/usr/src/man/man4i/termio.4i new file mode 100644 index 0000000000..c30fdd5262 --- /dev/null +++ b/usr/src/man/man4i/termio.4i @@ -0,0 +1,2193 @@ +.\" Copyright (c) 2005, Sun Microsystems, Inc. All Rights Reserved. +.\" Copyright 2019, Joyent, Inc. All Rights Reserved. +.\" Copyright 1989 AT&T +.\" The contents of this file are subject to the terms of the +.\" Common Development and Distribution License (the "License"). +.\" You may not use this file except in compliance with the License. +.\" +.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE +.\" or http://www.opensolaris.org/os/licensing. +.\" See the License for the specific language governing permissions +.\" and limitations under the License. +.\" +.\" When distributing Covered Code, include this CDDL HEADER in each +.\" file and include the License file at usr/src/OPENSOLARIS.LICENSE. +.\" If applicable, add the following below this CDDL HEADER, with the +.\" fields enclosed by brackets "[]" replaced with your own identifying +.\" information: Portions Copyright [yyyy] [name of copyright owner] +.Dd August 13, 2021 +.Dt TERMIO 4I +.Os +.Sh NAME +.Nm termio +.Nd general terminal interface +.Sh SYNOPSIS +.In termio.h +.Fn ioctl "int fildes" "int request" "struct termio *arg" +.Fn ioctl "int fildes" "int request" "int arg" +.Pp +.In termios.h +.Fn ioctl "int fildes" "int request" "struct termios *arg" +.Sh DESCRIPTION +This release supports a general interface for asynchronous communications ports +that is hardware-independent. +The user interface to this functionality is using +function calls (the preferred interface) described in +.Xr termios 3C +or +.Fn ioctl +commands described in this section. +This section also discusses the +common features of the terminal subsystem which are relevant with both user +interfaces. +.Pp +When a terminal file is opened, it normally causes the process to wait until a +connection is established. +In practice, user programs seldom open terminal +files; they are opened by the system and become a user's standard input, +output, and error files. +The first terminal file opened by the session leader +that is not already associated with a session becomes the controlling terminal +for that session. +The controlling terminal plays a special role in handling +quit and interrupt signals, as discussed below. +The controlling terminal is +inherited by a child process during a +.Xr fork 2 . +A process can break this +association by changing its session using +.Xr setsid 2 . +.Pp +A terminal associated with one of these files ordinarily operates in +full-duplex mode. +Characters may be typed at any time, even while output is +occurring, and are only lost when the character input buffers of the system +become completely full, which is rare. +For example, the number of characters in +the line discipline buffer may exceed +.Brq Dv MAX_CANON +and +.Dv IMAXBEL +(see below) is not set, or the user may accumulate +.Brq Dv MAX_INPUT +number of input characters that have not yet been read by some program. +When the input +limit is reached, all the characters saved in the buffer up to that point are +thrown away without notice. +.Ss "Session Management (Job Control)" +A control terminal will distinguish one of the process groups in the session +associated with it to be the foreground process group. +All other process +groups in the session are designated as background process groups. +This foreground process group plays a special role in handling signal-generating +input characters, as discussed below. +By default, when a controlling terminal +is allocated, the controlling process's process group is assigned as +foreground process group. +.Pp +Background process groups in the controlling process's session are subject to a +job control line discipline when they attempt to access their controlling +terminal. +Process groups can be sent signals that will cause them to stop, +unless they have made other arrangements. +An exception is made for members of +orphaned process groups. +.Pp +An orphaned process group is one where the process group (see +.Xr getpgid 2 ) +has no members with a parent in a different process group but sharing the same +controlling terminal. +When a member of an orphaned process group attempts to +access its controlling terminal, EIO is returned because there would be no way +to restart the process if it were stopped on one of these signals. +.Pp +If a member of a background process group attempts to read its controlling +terminal, its process group will be sent a +.Dv SIGTTIN +signal, which will +normally cause the members of that process group to stop. +If, however, the +process is ignoring or holding +.Dv SIGTTIN , +or is a member of an orphaned +process group, the read will fail with +.Va errno +set to +.Er EIO , +and no signal is sent. +.Pp +If a member of a background process group attempts to write its controlling +terminal and the +.Dv TOSTOP +bit is set in the +.Fa c_lflag +field, its process group is sent a +.Dv SIGTTOU +signal, which will normally cause the +members of that process group to stop. +If, however, the process is ignoring or +holding +.Dv SIGTTOU , +the write will succeed. +If the process is not ignoring +or holding +.Dv SIGTTOU +and is a member of an orphaned process group, the +write will fail with +.Va errno +set to +.Er EIO , +and no signal will be sent. +.Pp +If +.Dv TOSTOP +is set and a member of a background process group attempts to +.Fn ioctl +its controlling terminal, and that +.Fn ioctl +will modify terminal parameters (for example, +.Dv TCSETA , +.Dv TCSETAW , +.Dv TCSETAF , +or +.Dv TIOCSPGRP ) , +its process group will be sent a +.Dv SIGTTOU +signal, which will normally cause the members of that process group to stop. +If, however, the process is ignoring or holding +.Dv SIGTTOU , +the ioctl will succeed. +If the process is not ignoring or holding +.Dv SIGTTOU +and is a member of an orphaned +process group, the write will fail with +.Va errno +set to +.Er EIO , +and no signal will be sent. +.Ss "Canonical Mode Input Processing" +Normally, terminal input is processed in units of lines. +A line is delimited by +a newline +.Po +.Sy ASCII LF +.Pc +character, an end-of-file +.Po +.Sy ASCII EOT +.Pc +character, or an end-of-line character. +This means that a program attempting to +read will block until an entire line has been typed. +Also, no matter how many +characters are requested in the read call, at most one line will be returned. +It is not necessary, however, to read a whole line at once; any number of +characters may be requested in a read, even one, without losing information. +.Pp +During input, erase, erase2, and kill processing is normally done. +The +.Sy ERASE +and +.Sy ERASE2 +character (by default, the character +.Sy DEL +for +.Sy ERASE +and +.Sy Control-h +for +.Sy ERASE2 ) +erases the last character typed. +The +.Sy WERASE +character (the character +.Sy Control-w ) +erases the +last "word" typed in the current input line (but not any preceding spaces or +tabs). +A +.Dq word +is defined as a sequence of non-blank characters, with tabs counted as blanks. +None of +.Sy ERASE +or +.Sy ERASE2 +or +.Sy WERASE +will erase beyond the beginning of the line. +The +.Sy KILL +character (by default, +the character +.Sy NAK ) +kills (deletes) the entire input line, and optionally +outputs a newline character. +All these characters operate on a key stroke basis, +independent of any backspacing or tabbing that may have been done. +The +.Sy REPRINT +character (the character +.Sy Control-r ) +prints a newline followed by all characters that have not been read. +Reprinting also occurs automatically if +characters that would normally be erased from the screen are fouled by program +output. +The characters are reprinted as if they were being echoed; +consequencely, if +.Dv ECHO +is not set, they are not printed. +.Pp +The +.Sy ERASE , +.Sy ERASE2 , +and +.Sy KILL +characters may be entered literally by preceding them with the escape character. +In this case, the escape character is not read. +The erase, erase2, and kill characters may be changed. +.Ss "Non-canonical Mode Input Processing" +In non-canonical mode input processing, input characters are not assembled into +lines, and erase and kill processing does not occur. +The +.Sy MIN +and +.Sy TIME +values are used to determine how to process the characters received. +.Pp +.Sy MIN +represents the minimum number of characters that should be received +when the read is satisfied (that is, when the characters are returned to the +user). +.Sy TIME +is a timer of 0\&.10-second granularity that is used to timeout +bursty and short-term data transmissions. +The four possible values for +.Sy MIN +and +.Sy TIME +and their interactions are described below. +.Bl -tag -width "Case A: Min > 0, Time > 0" +.It Sy Case A: MIN > 0, TIME > 0 +In this case, +.Sy TIME +serves as an intercharacter timer and is activated +after the first character is received. +Since it is an intercharacter timer, it +is reset after a character is received. +The interaction between +.Sy MIN +and +.Sy TIME +is as follows: as soon as one character is received, the +intercharacter timer is started. +If +.Sy MIN +characters are received before +the intercharacter timer expires (note that the timer is reset upon receipt of +each character), the read is satisfied. +If the timer expires before +.Sy MIN +characters are received, the characters received to that point are returned to +the user. +Note that if +.Sy TIME +expires, at least one character will be +returned because the timer would not have been enabled unless a character was +received. +In this case (MIN > 0, TIME > 0), the read sleeps until the +.Sy MIN +and +.Sy TIME +mechanisms are activated by the receipt of the first character. +If the number of characters read is less than the number of characters +available, the timer is not reactivated and the subsequent read is satisfied +immediately. +.It Sy Case B: MIN > 0, TIME = 0 +In this case, since the value of +.Sy TIME +is zero, the timer plays no role +and only +.Sy MIN +is significant. +A pending read is not satisfied until +.Sy MIN +characters are received (the pending read sleeps until +.Sy MIN +characters are received). +A program that uses this case to read record based +terminal +.Sy I/O +may block indefinitely in the read operation. +.It Sy Case C: MIN = 0, TIME > 0 +In this case, since +.Sy MIN +0, +.Sy TIME +no longer represents an +intercharacter timer: it now serves as a read timer that is activated as soon +as a +.Xr read 2 +is done. +A read is satisfied as soon as a single character is +received or the read timer expires. +Note that, in this case, if the timer +expires, no character is returned. +If the timer does not expire, the only way +the read can be satisfied is if a character is received. +In this case, the +read will not block indefinitely waiting for a character; if no character is +received within +.Sy TIME +*\&.10 seconds after the read is initiated, the read +returns with zero characters. +.It Sy Case D: MIN = 0, TIME = 0 +In this case, return is immediate. +The minimum of either the number of +characters requested or the number of characters currently available is +returned without waiting for more characters to be input. +.El +.Ss "Comparing Different Cases of MIN, TIME Interaction" +Some points to note about +.Sy MIN +and +.Sy TIME : +.Bl -bullet -offset 2n +.It +In the following explanations, note that the interactions of +.Sy MIN +and +.Sy TIME +are not symmetric. +For example, when +.Sy MIN +> 0 and +.Sy TIME += 0, +.Sy TIME +has no effect. +However, in the opposite case, where +.Sy MIN += 0 and +.Sy TIME +> 0, both +.Sy MIN +and +.Sy TIME +play a role in that +.Sy MIN +is satisfied with the receipt of a single character. +.It +Also note that in case A +.Po +.Sy MIN +> 0, +.Sy TIME +> 0 +.Pc , +.Sy TIME +represents +an intercharacter timer, whereas in case C +.Po +.Sy MIN += 0, +.Sy TIME +> 0 +.Pc , +.Sy TIME +represents a read timer. +.El +.Pp +These two points highlight the dual purpose of the +.Sy MIN/TIME +feature. +Cases A and B, where +.Sy MIN +> 0, exist to handle burst mode activity (for +example, file transfer programs), where a program would like to process at +least +.Sy MIN +characters at a time. +In case A, the inteercharacter timer is +activated by a user as a safety measure; in case B, the timer is turned off. +.Pp +Cases C and D exist to handle single character, timed transfers. +These cases +are readily adaptable to screen-based applications that need to know if a +character is present in the input queue before refreshing the screen. +In case +C, the read is timed, whereas in case D, it is not. +.Pp +Another important note is that +.Sy MIN +is always just a minimum. +It does not +denote a record length. +For example, if a program does a read of 20 bytes, +.Sy MIN +is 10, and 25 characters are present, then 20 characters will be +returned to the user. +.Ss "Writing Characters" +When one or more characters are written, they are transmitted to the terminal +as soon as previously written characters have finished typing. +nputt characters +are echoed as they are typed if echoing has been enabled. +If a process produces +characters more rapidly than they can be typed, it will be suspended when its +output queue exceeds some limit. +When the queue is drained down to some +threshold, the program is resumed. +.Ss "Special Characters" +Certain characters have special functions on input. +These functions and their default character values are summarized as follows: +.Bl -tag -width REPRINT +.It Sy INTR +(Control-c or +.Sy ASCII ETX ) +generates a +.Dv SIGINT +signal. +.Dv SIGINT +is sent to all foreground processes associated with the controlling terminal. +Normally, each such process is forced to terminate, but arrangements may be +made either to ignore the signal or to receive a trap to an agreed upon +location. +(See +.Xr signal.h 3HEAD ) . +.It Sy QUIT +(Control-| or +.Sy ASCII FS ) +generates a +.Dv SIGQUIT +signal. +Its treatment +is identical to the interrupt signal except that, unless a receiving process +has made other arrangements, it will not only be terminated but a core image +file (called +.Pa core ) +will be created in the current working directory. +.It Sy ERASE +(DEL) erases the preceding character. +It does not erase beyond +the start of a line, as delimited by a +.Sy NL , +.Sy EOF , +.Sy EOL , +or +.Sy EOL2 +character. +.It Sy ERASE2 +(Control-h or +.Sy ASCII BS ) +erases the preceding character, with behaviour identical to that of ERASE. +.It Sy WERASE +(Control-w or +.Sy ASCII ETX ) +erases the preceding +.Dq word . +It does not erase beyond the start of a line, as delimited by a +.Sy NL , +.Sy EOF , +.Sy EOL , +or +.Sy EOL2 +character. +.It Sy KILL +(Control-u or +.Sy ASCII NAK ) +deletes the entire line, as delimited by a +.Sy NL , +.Sy EOF , +.Sy EOL , +or +.Sy EOL2 +character. +.It Sy REPRINT +(Control-r or +.Sy ASCII DC2 ) +reprints all characters, preceded by a newline, that have not been read. +.It Sy EOF +(Control-d or +.Sy ASCII EOT ) +may be used to generate an end-of-file from a terminal. +When received, all the characters waiting to be read are immediately +passed to the program, without waiting for a newline, and the +.Sy EOF +is discarded. +Thus, if no characters are waiting (that is, the +.Sy EOF +occurred +at the beginning of a line) zero characters are passed back, which is the +standard end-of-file indication. +Unless escaped, the +.Sy EOF +character is not +echoed. +Because +.Sy EOT +is the default +.Sy EOF +character, this prevents +terminals that respond to +.Sy EOT +from hanging up. +.It Sy NL +.Pq Sy ASCII LF +is the normal line delimiter. +It cannot be changed or escaped. +.It Sy EOL +.Pq Sy ASCII NULL +is an additional line delimiter, like +.Sy NL . +It is not normally used. +.It Sy EOL2 +is another additional line delimiter. +.It Sy SWTCH +(Control-z or +.Sy ASCII EM ) +Header file symbols related to this special +character are present for compatibility purposes only and the kernel takes no +special action on matching SWTCH (except to discard the character). +.It Sy SUSP +(Control-z or +.Sy ASCII SUB ) +generates a +.Dv SIGTSTP +signal. +.Dv SIGTSTP +stops all processes in the foreground process group for that terminal. +.It Sy DSUSP +(Control-y or +.Sy ASCII EM ) . +It generates a +.Dv SIGTSTP +signal as +.Sy SUSP +does, but the signal is sent when a process in the foreground +process group attempts to read the +.Sy DSUSP +character, rather than when it is typed. +.It Sy STOP +(Control-s or +.Sy ASCII DC3 ) +can be used to suspend output temporarily. +It is useful with +.Sy CRT +terminals to prevent output from disappearing before it can be read. +While output is suspended, +.Sy STOP +characters are ignored and +not read. +.It Sy START +(Control-q or +.Sy ASCII DC1 ) +is used to resume output. +Output has been suspended by a +.Sy STOP +character. +While output is not suspended, +.Sy START +characters are ignored and not read. +.It Sy DISCARD +(Control-o or +.Sy ASCII SI ) +causes subsequent output to be discarded. +Output is discarded until another +.Sy DISCARD +character is typed, more input +arrives, or the condition is cleared by a program. +.It Sy STATUS +(Control-t or +.Sy ASCII DC4 ) +generates a +.Dv SIGINFO +signal. +Processes with a handler will output status information when they receive +.Dv SIGINFO , +for +example, +.Xr dd 8 . +If a process does not have a +.Dv SIGINFO +handler, the +signal will be ignored. +.It Sy LNEXT +(Control-v or +.Sy ASCII SYN ) +causes the special meaning of the next character to be ignored. +This works for all the special characters mentioned above. +It +allows characters to be input that would otherwise be interpreted by the system +(for example +.Sy KILL , +.Sy QUIT ) . +The character values for +.Sy INTR , +.Sy QUIT , +.Sy ERASE , +.Sy ERASE2 , +.Sy WERASE , +.Sy KILL , +.Sy REPRINT , +.Sy EOF , +.Sy EOL , +.Sy EOL2 , +.Sy SWTCH , +.Sy SUSP , +.Sy DSUSP , +.Sy STOP , +.Sy START , +.Sy DISCARD , +.Sy STATUS , +and +.Sy LNEXT +may be changed to suit individual tastes. +If the value of a special control character +is +.Dv _POSIX_VDISABLE +(0), the function of that special control character is disabled. +The +.Sy ERASE , +.Sy ERASE2 , +.Sy KILL , +and +.Sy EOF +characters may be +escaped by a preceding backslash (\e) character, in which case no special +function is done. +Any of the special characters may be preceded by the +.Sy LNEXT +character, in +which case no special function is done. +.El +.Ss "Modem Disconnect" +When a modem disconnect is detected, a +.Dv SIGHUP +signal is sent to the +terminal's controlling process. +Unless other arrangements have been made, these +signals cause the process to terminate. +If +.Dv SIGHUP +is ignored or caught, +any subsequent read returns with an end-of-file indication until the terminal +is closed. +.Pp +If the controlling process is not in the foreground process group of the +terminal, a +.Dv SIGTSTP +is sent to the terminal's foreground process group. +Unless other arrangements have been made, these signals cause the processes to +stop. +.Pp +Processes in background process groups that attempt to access the controlling +terminal after modem disconnect while the terminal is still allocated to the +session will receive appropriate +.Dv SIGTTOU +and +.Dv SIGTTIN +signals. +Unless other arrangements have been made, this signal causes the processes to +stop. +.Pp +The controlling terminal will remain in this state until it is reinitialized +ithh a successful open by the controlling process, or deallocated by the +controlling process. +.Ss "Terminal Parameters" +The parameters that control the behavior of devices and modules providing the +.Vt termios +interface are specified by the +.Vt termios +structure defined by +.In termios.h . +Several +.Xr ioctl 2 +system calls that fetch or change +these parameters use this structure that contains the following members: +.Bd -literal -offset 2n +tcflag_t c_iflag; /* input modes */ +tcflag_t c_oflag; /* output modes */ +tcflag_t c_cflag; /* control modes */ +tcflag_t c_lflag; /* local modes */ +cc_t c_cc[NCCS]; /* control chars */ +.Ed +.Pp +The special control characters are defined by the array +.Fa c_cc . +The symbolic name +.Dv NCCS +is the size of the Control-character array and is also +defined by +.In termios.h . +The relative positions, subscript names, and +typical default values for each function are as follows: +.Bl -column "Relative Position" "Subscript Name" "Typical Default Value" +.It Relative Position Ta Subscript Name Ta Typical Default Value +.It 0 Ta Dv VINTR Ta Sy ETX +.It 1 Ta Dv VQUIT Ta Sy FS +.It 2 Ta Dv VERASE Ta Sy DEL +.It 3 Ta Dv VKILL Ta Sy NAK +.It 4 Ta Dv VEOF Ta Sy EOT +.It 5 Ta Dv VEOL Ta Sy NUL +.It 6 Ta Dv VEOL2 Ta Sy NUL +.It 7 Ta Dv VWSTCH Ta Sy NUL +.It 8 Ta Dv VSTART Ta Sy NUL +.It 9 Ta Dv VSTOP Ta Sy DC3 +.It 10 Ta Dv VSUSP Ta Sy SUB +.It 11 Ta Dv VDSUSP Ta Sy EM +.It 12 Ta Dv VREPRINT Ta Sy DC2 +.It 13 Ta Dv VDISCARD Ta Sy SI +.It 14 Ta Dv VWERASE Ta Sy ETB +.It 15 Ta Dv VLNEXT Ta Sy SYN +.It 16 Ta Dv VSTATUS Ta Sy DC4 +.It 17 Ta Dv VERASE2 Ta Sy BS +.It 18-19 Ta Reserved Ta +.El +.Ss "Input Modes" +The +.Fa c_iflag +field describes the basic terminal input control: +.Pp +.Bl -tag -width "IMAXBEL" -offset 2n -compact +.It Dv IGNBRK +Ignore break condition. +.It Dv BRKINT +Signal interrupt on break. +.It Dv IGNPAR +Ignore characters with parity errors. +.It Dv PARMRK +Mark parity errors. +.It Dv INPCK +Enable input parity check. +.It Dv ISTRIP +Strip character. +.It Dv INLCR +Map NL to CR on input. +.It Dv IGNCR +Ignore CR. +.It Dv ICRNL +Map CR to NL on input. +.It Dv IUCLC +Map upper-case to lower-case on input. +.It Dv IXON +Enable start/stop output control. +.It Dv IXANY +Enable any character to restart output. +.It Dv IXOFF +Enable start/stop input control. +.It Dv IMAXBEL +Echo +.Sy BEL +on input line too long. +.El +.Pp +If +.Dv IGNBRK +is set, a break condition (a character framing error with data +all zeros) detected on input is ignored, that is, not put on the input queue +and therefore not read by any process. +If +.Dv IGNBRK +is not set and +.Dv BRKINT +is set, the break condition shall flush the input and output +queues and if the terminal is the controlling terminal of a foreground process +group, the break condition generates a single +.Dv SIGINT +signal to that +foreground process group. +If neither +.Dv IGNBRK +nor +.Dv BRKINT +is set, a +break condition is read as a single +.Ql \e0 +.Pq Sy ASCII NULL +character, or if +.Dv PARMRK +is set, as +.Ql \e377 , +.Ql \e0 , +.Em c , +where +.Ql \e377 +is a single character +with value 377 octal (0xff hex, 255 decimal), +.Ql \e0 +is a single character with value +.Sy 0 , +and +.Em c +is the errored character received. +.Pp +If +.Dv IGNPAR +is set, a byte with framing or parity errors (other than +break) is ignored. +.Pp +If +.Dv PARMRK +is set, and +.Dv IGNPAR +is not set, a byte with a framing or +parity error (other than break) is given to the application as the +three-character sequence: +.Ql \e377 , +.Ql \e0 , +c, where +.Ql \e377 +is a single character with value 377 octal (0xff hex, 255 decimal), +.Ql \e0 +is a single character with value 0, and c is the errored character received. +To avoid ambiguity in this case, if +.Dv ISTRIP +is not set, a valid character +of +.Ql \e377 +is given to the application as +.Ql \e377 . +If neither +.Dv IGNPAR +nor +.Dv PARMRK +is set, a framing or parity error (other than break) is given to +the application as a single +.Ql \e0 +.Po +.Sy ASCII NULL +.Pc +character. +.Pp +If +.Dv INPCK +is set, input parity checking is enabled. +If +.Dv INPCK +is not +set, input parity checking is disabled. +This allows output parity generation +without input parity errors. +Note that whether input parity checking is +enabled or disabled is independent of whether parity detection is enabled or +disabled. +If parity detection is enabled but input parity checking is +disabled, the hardware to which the terminal is connected will recognize the +parity bit, but the terminal special file will not check whether this is set +correctly or not. +.Pp +If +.Dv ISTRIP +is set, valid input characters are first stripped to seven +bits, otherwise all eight bits are processed. +.Pp +If +.Dv INLCR +is set, a received +.Sy NL +character is translated into a +.Sy CR +character. +If +.Dv IGNCR +is set, a received +.Sy CR +character is ignored (not read). +Otherwise, if +.Dv ICRNL +is set, a received +.Sy CR +character is translated into a +.Sy NL +character. +.Pp +If +.Dv IUCLC +is set, a received upper case, alphabetic character is +translated into the corresponding lower case character. +.Pp +If +.Dv IXON +is set, start/stop output control is enabled. +A received +.Sy STOP +character suspends output and a received +.Sy START +character +restarts output. +The +.Sy STOP +and +.Sy START +characters will not be read, +but will merely perform flow control functions. +If +.Dv IXANY +is set, any +input character restarts output that has been suspended. +.Pp +If +.Dv IXOFF +is set, the system transmits a +.Sy STOP +character when the +input queue is nearly full, and a +.Sy START +character when enough input has +been read so that the input queue is nearly empty again. +.Pp +If +.Dv IMAXBEL +is set, the +.Sy ASCII BEL +character is echoed if the input stream overflows. +Further input is not stored, but any input already present in +the input stream is not disturbed. +If +.Dv IMAXBEL +is not set, no +.Sy BEL +character is echoed, and all input present in the input queue is discarded if +the input stream overflows. +.Ss "Output Modes" +The +.Fa c_oflag +field specifies the system treatment of output: +.Pp +.Bl -tag -width ONLRET -offset 2n -compact +.It Dv OPOST +Post-process output. +.It Dv OLCUC +Map lower case to upper on output. +.It Dv ONLCR +Map NL to CR-NL on output. +.It Dv OCRNL +Map CR to NL on output. +.It Dv ONOCR +No +.Sy CR +output at column 0. +.It Dv ONLRET +.Sy NL +performs +.Sy CR +function. +.It Dv OFILL +Use fill characters for delay. +.It Dv OFDEL +Fill is +.Sy DEL , +else +.Sy INULL . +.It Dv NLDLY +Select newline delays: +.Bl -tag -width NL0 -compact -offset 2n +.It Sy NL0 +.It Sy NL1 +.El +.It Dv CRDLY +Select carriage-return delays: +.Bl -tag -width CR0 -compact -offset 2n +.It Dv CR0 +.It Dv CR1 +.It Dv CR2 +.It Dv CR3 +.El +.It Dv TABDLY +Select horizontal tab delays or tab expansion: +.Bl -tag -width XTABS -compact -offset 2n +.It Dv TAB0 +.It Dv TAB1 +.It Dv TAB2 +.It Dv TAB3 +Expand tabs to spaces +.It Dv XTABS +Expand tabs to spaces +.El +.It Dv BSDLY +Select backspace delays: +.Bl -tag -width BS0 -offset 2n -compact +.It Dv BS0 +.It Dv BS1 +.El +.It Dv VTDLY +Select vertical tab delays: +.Bl -tag -width VT0 -offset 2n -compact +.It Dv VT0 +.It Dv VT1 +.El +.It Dv FFDLY +Select form feed delays: +.Bl -tag -width FF0 -offset 2n -compact +.It Dv FF0 +.It Dv FF1 +.El +.El +.Pp +If +.Dv OPOST +is set, output characters are post-processed as indicated by the +remaining flags; otherwise, characters are transmitted without change. +.Pp +If +.Dv OLCUC +is set, a lower case alphabetic character is transmitted as the +corresponding upper case character. +This function is often used in conjunction +with +.Dv IUCLC . +.Pp +If +.Dv ONLCR +is set, the +.Sy NL +character is transmitted as the +.Sy CR-NL +character pair. +If +.Dv OCRNL +is set, the +.Sy CR +character is transmitted as the +.Sy NL +character. +If +.Dv ONOCR +is set, no +.Sy CR +character is transmitted when at column 0 (first position). +If +.Dv ONRET +is set, the +.Sy NL +character is assumed to do the carriage-return function; the column +pointer is set to 0 and the delays specified for +.Sy CR +are used. +Otherwise, the +.Sy NL +character is assumed to do just the line-feed function; the column +pointer remains unchanged. +The column pointer is also set to 0 if the +.Sy CR +character is actually transmitted. +.Pp +The delay bits specify how long transmission stops to allow for mechanical or +other movement when certain characters are sent to the terminal. +In all cases, a value of 0 indicates no delay. +If +.Dv OFILL +is set, fill characters are transmitted for delay instead of a timed delay. +This is useful for high baud rate terminals that need only a minimal delay. +If +.Dv OFDEL +is set, the +fill character is +.Sy DEL ; +otherwise it is +.Sy NULL . +.Pp +If a form-feed or vertical-tab delay is specified, it lasts for about 2 +seconds. +.Pp +Newline delay lasts about 0\&.10 seconds. +If +.Dv ONLRET +is set, the carriage-return delays are used instead of the newline delays. +If +.Dv OFILL +is set, two fill characters are transmitted. +.Pp +Carriage-return delay type 1 is dependent on the current column position, type +2 is about 0\&.10 seconds, and type 3 is about 0\&.15 seconds. +If +.Dv OFILL +is set, delay type 1 transmits two fill characters, and type 2 transmits four +fill characters. +.Pp +Horizontal-tab delay type 1 is dependent on the current column position. +Type 2 is about 0\&.10 seconds. +Type 3 specifies that tabs are to be expanded into spaces. +If +.Dv OFILL +is set, two fill characters are transmitted for any delay. +.Pp +Backspace delay lasts about 0\&.05 seconds. +If +.Dv OFILL +is set, one fill character is transmitted. +.Pp +The actual delays depend on line speed and system load. +.Ss "Control Modes" +The +.Fa c_cflag +field describes the hardware control of the terminal: +.Bl -tag -width CIBAUDEXT -offset 2n +.It Dv CBAUD +Baud rate: +.Bl -tag -width B4000000 -compact +.It Dv B0 +Hang up +.It Dv B50 +50 baud +.It Dv B75 +75 baud +.It Dv B110 +110 baud +.It Dv B134 +134 baud +.It Dv B150 +150 baud +.It Dv B200 +200 baud +.It Dv B300 +300 baud +.It Dv B600 +600 baud +.It Dv B1200 +1200 baud +.It Dv B1800 +1800 baud +.It Dv B2400 +2400 baud +.It Dv B4800 +4800 baud +.It Dv B9600 +9600 baud +.It Dv B19200 +19200 baud +.It Dv B38400 +38400 baud +.It Dv B57600 +57600 baud +.It Dv B76800 +76800 baud +.It Dv B115200 +115200 baud +.It Dv B153600 +153600 baud +.It Dv B230400 +230400 baud +.It Dv B307200 +307200 baud +.It Dv B460800 +460800 baud +.It Dv B921600 +921600 baud +.It Dv B1000000 +1000000 baud +.It Dv B1152000 +1152000 baud +.It Dv B1500000 +1500000 baud +.It Dv B2000000 +2000000 baud +.It Dv B2500000 +2500000 baud +.It Dv B3000000 +3000000 baud +.It Dv B3500000 +3500000 baud +.It Dv B4000000 +4000000 baud +.El +.It Dv CSIZE +Character size: +.Bl -tag -width CIBAUDEXT -compact +.It Dv CS5 +5 bits +.It Dv CS6 +6 bits +.It Dv CS7 +7 bits +.It Dv CS8 +8 bits +.It Dv CSTOPB +Send two stop bits, else one +.It Dv CREAD +Enable receiver +.It Dv PARENB +Parity enable +.It Dv PARODD +Odd parity, else even +.It Dv HUPCL +Hang up on last close +.It Dv CLOCAL +Local line, else dial-up +.It Dv CIBAUD +Input baud rate, if different from output rate +.It Dv PAREXT +Extended parity for mark and space parity +.It Dv CRTSXOFF +Enable inbound hardware flow control +.It Dv CRTSCTS +Enable outbound hardware flow control +.It Dv CBAUDEXT +Bit to indicate output speed > B38400 +.It Dv CIBAUDEXT +Bit to indicate input speed > B38400 +.El +.El +.Pp +The +.Dv CBAUD +bits together with the +.Dv CBAUDEXT +bit specify the output baud rate. +To retrieve the output speed from the +.Vt termios +structure pointed to by +.Fa termios_p +see the following code segment. +.Bd -literal -offset 2n +speed_t ospeed; +if (termios_p->c_cflag & CBAUDEXT) + ospeed = (termios_p->c_cflag & CBAUD) + CBAUD + 1; +else + ospeed = termios_p->c_cflag & CBAUD; +.Ed +.Pp +To store the output speed in the termios structure pointed to by +.Fa termios_p +see the following code segment. +.Bd -literal -offset 2n +speed_t ospeed; +if (ospeed > CBAUD) { + termios_p->c_cflag |= CBAUDEXT; + ospeed -= (CBAUD + 1); +} else { + termios_p->c_cflag &= ~CBAUDEXT; +} +termios_p->c_cflag = + (termios_p->c_cflag & ~CBAUD) | (ospeed & CBAUD); +.Ed +.Pp +The zero baud rate, +.Dv B0 , +is used to hang up the connection. +If +.Dv B0 +is specified, the data-terminal-ready signal is not asserted. +Normally, this disconnects the line. +.Pp +If the +.Dv CIBAUDEXT +or +.Dv CIBAUD +bits are not zero, they specify the input baud rate, with the +.Dv CBAUDEXT +and +.Dv CBAUD +bits specifying the output baud rate; otherwise, the output and input baud +rates are both specified by the +.Dv CBAUDEXT +and +.Dv CBAUD +bits. +The values for the +.Dv CIBAUD +bits are the same as the values for the +.Dv CBAUD +bits, shifted left +.Dv IBSHIFT +bits. +For any particular hardware, impossible speed changes are +ignored. +To retrieve the input speed in the +.Vt termios +structure pointed to +by +.Fa termios_p +see the following code segment. +.Bd -literal -offset 2n +speed_t ispeed; +if (termios_p->c_cflag & CIBAUDEXT) { + ispeed = ((termios_p->c_cflag & CIBAUD) >> IBSHIFT) + + (CIBAUD >> IBSHIFT) + 1; +} else { + ispeed = (termios_p->c_cflag & CIBAUD) >> IBSHIFT; +} +.Ed +.Pp +To store the input speed in the +.Vt termios +structure pointed to by +.Fa termios_p +see the following code segment. +.Bd -literal -offset 2n +speed_t ispeed; +if (ispeed == 0) { + ispeed = termios_p->c_cflag & CBAUD; + if (termios_p->c_cflag & CBAUDEXT) + ispeed += (CBAUD + 1); +} +if ((ispeed << IBSHIFT) > CIBAUD) { + termios_p->c_cflag |= CIBAUDEXT; + ispeed -= ((CIBAUD >> IBSHIFT) + 1); +} else { + termios_p->c_cflag &= ~CIBAUDEXT; +} +termios_p->c_cflag = + (termios_p->c_cflag & ~CIBAUD) | ((ispeed << IBSHIFT) & CIBAUD); +.Ed +.Pp +The +.Dv CSIZE +bits specify the character size in bits for both transmission and reception. +This size does not include the parity bit, if any. +If +.Dv CSTOPB +is set, two stop bits are used; otherwise, one stop bit is used. +For example, at 110 baud, two stops bits are required. +.Pp +If +.Dv PARENB +is set, parity generation and detection is enabled, and a +parity bit is added to each character. +If parity is enabled, the +.Dv PARODD +flag specifies odd parity if set; otherwise, even parity is used. +.Pp +If +.Dv CREAD +is set, the receiver is enabled. +Otherwise, no characters are received. +.Pp +If +.Dv HUPCL +is set, the line is disconnected when the last process with the +line open closes it or terminates. +That is, the data-terminal-ready signal is not asserted. +.Pp +If +.Dv CLOCAL +is set, the line is assumed to be a local, direct connection +with no modem control; otherwise, modem control is assumed. +.Pp +If +.Dv CRTSXOFF +is set, inbound hardware flow control is enabled. +.Pp +If +.Dv CRTSCTS +is set, outbound hardware flow control is enabled. +.Pp +The four possible combinations for the state of +.Dv CRTSCTS +and +.Dv CRTSXOFF +bits and their interactions are described below. +.Bl -tag -width "Case C:" +.It Sy Case A : +.Dv CRTSCTS +off, +.Dv CRTSXOFF +off. +In this case the hardware flow control is disabled. +.It Sy Case B : +.Dv CRTSCTS +on, +.Dv CRTSXOFF +off. +In this case only outbound hardware flow control is enabled. +The state of CTS signal is used to do outbound flow control. +It is expected that output will be suspended if CTS is low and resumed +when CTS is high. +.It Sy Case C : +.Dv CRTSCTS +off, +.Dv CRTSXOFF +on. +In this case only inbound hardware flow control is enabled. +The state of RTS signal is used to do inbound flow control. +It is expected that input will be suspended if RTS is low and resumed when RTS +is high. +.It Sy Case D : +.Dv CRTSCTS +on, +.Dv CRTSXOFF +on. +In this case both inbound and outbound hardware flow control are enabled. +Uses the state of CTS signal to do outbound +flow control and RTS signal to do inbound flow control. +.El +.Ss "Local Modes" +The +.Fa c_lflag +field of the argument structure is used by the line +discipline to control terminal functions. +The basic line discipline provides the following: +.Pp +.Bl -tag -offset 2n -width SIGTTOU -compact +.It Dv ISIG +Enable signals. +.It Dv ICANON +Canonical input (erase and kill processing). +.It Dv XCASE +Canonical upper/lower presentation. +.It Dv ECHO +Enable echo. +.It Dv ECHOE +Echo erase character as +.Sy BS Ns - Ns Sy SP Ns - Ns Sy BS +&. +.It Dv ECHOK +Echo +.Sy NL +after kill character. +.It Dv ECHONL +Echo +.Sy NL . +.It Dv NOFLSH +Disable flush after interrupt or quit. +.It Dv TOSTOP +Send +.It Dv SIGTTOU +for background output. +.It Dv ECHOCTL +Echo control characters as +.Em char , +delete as ^?. +.It Dv ECHOPRT +Echo erase character as character erased. +.It Dv ECHOKE +.Sy BS Ns - Ns Sy SP Ns - Ns Sy BS +erase entire line on line kill. +.It Dv FLUSHO +Output is being flushed. +.It Dv PENDIN +Retype pending input at next read or input character. +.It Dv IEXTEN +Enable extended (implementation-defined) functions. +.El +.Pp +If +.Dv ISIG +is set, each input character is checked against the special +control characters +.Sy INTR , +.Sy QUIT , +.Sy SWTCH , +.Sy SUSP , +.Sy STATUS , +and +.Sy DSUSP . +If an input character matches one of these control characters, the function +associated with that character is performed. +.Po +Note: If +.Sy SWTCH +is set and the character matches, the character is simply discarded. +No other action is taken. +.Pc +If +.Dv ISIG +is not set, no checking is done. +Thus, these special +input functions are possible only if +.Dv ISIG +is set. +.Pp +If +.Dv ICANON +is set, canonical processing is enabled. +This enables the erase +and kill edit functions, and the assembly of input characters into lines +delimited by +.Sy NL-c , +.Sy EOF , +.Sy EOL , +and +.Sy EOL . +If +.Dv ICANON +is not set, read requests are satisfied directly from the input queue. +A read is not satisfied until at least +.Sy MIN +characters have been received or the timeout value +.Sy TIME +has expired between characters. +This allows fast bursts of input to be read efficiently while still allowing +single character input. +The time value represents tenths of seconds. +.Pp +If +.Dv XCASE +is set and +.Dv ICANON +is set, an upper case letter is +accepted on input if preceded by a backslash +.Ql \e +character, and is output preceded by a backslash +.Ql \e +character. +In this mode, the +following escape sequences are generated on output and accepted on input: +.Bl -column "FOR:" "USE:" -offset 2n +.It FOR: Ta USE: +.It ` Ta \e' +.It | Ta \e! +.It \(ap Ta \e^ +.It { Ta \e( +.It } Ta \e) +.It \e Ta \e\e +.El +.Pp +For example, input A as \ea, \en as \e\en, and \eN as \e\e\en. +.Pp +If +.Dv ECHO +is set, characters are echoed as received. +.Pp +When +.Dv ICANON +is set, the following echo functions are possible. +.Bl -bullet -offset indent +.It +If +.Dv ECHO +and +.Dv ECHOE +are set, and +.Dv ECHOPRT +is not set, the +.Sy ERASE , +.Sy ERASE2 , +and +.Sy WERASE +characters are echoed as one or +more ASCII BS SP BS, which clears the last character(s) from a +.Sy CRT +screen. +.It +If +.Dv ECHO , +.Dv ECHOPRT , +and +.Dv IEXTEN +are set, the first +.Sy ERASE , +.Sy ERASE2 , +and +.Sy WERASE +character in a sequence echoes as a backslash +.Ql \e , +followed by the characters being erased. +Subsequent +.Sy ERASE +and +.Sy WERASE +characters echo the characters being erased, in reverse order. +The +next non-erase character causes a +.Ql / +(slash) to be typed before it is echoed. +.Dv ECHOPRT +should be used for hard copy terminals. +.It +If +.Dv ECHOKE +and +.Dv IEXTEN +are set, the kill character is echoed by +erasing each character on the line from the screen (using the mechanism +selected by +.Dv ECHOE +and +.Dv ECHOPR ) . +.It +If +.Dv ECHOK +is set, and +.Dv ECHOKE +is not set, the +.Sy NL +character is +echoed after the kill character to emphasize that the line is deleted. +Note +that a +.Ql \e +(escape) character or an +.Sy LNEXT +character preceding the erase +or kill character removes any special function. +.It +If +.Dv ECHONL +is set, the +.Sy NL +character is echoed even if +.Dv ECHO +is not set. +This is useful for terminals set to local echo (so called +half-duplex). +.El +.Pp +If +.Dv ECHOCTL +and +.Dv IEXTEN +are set, all control characters (characters +with codes between 0 and 37 octal) other than +.Sy ASCII TAB , +.Sy ASCII NL , +the +.Sy START +character, and the +.Sy STOP +character, +.Sy ASCII CR , +and +.Sy ASCII BS +are echoed as +.No ^ Ns Em X , +where +.Em X +is the character given by adding +.Ql 100 +octal to the code of the control character (so +that the character with octal code +.Ql 1 +is echoed as +.No ^ Ns Sy A ) , +and the +.Sy ASCII DEL +character, +with code +.Ql 177 +octal, is echoed as +.No ^ Ns Sy \&? . +.Pp +If +.Dv NOFLSH +is set, the normal flush of the input and output queues +associated with the +.Sy INTR , +.Sy QUIT , +.Sy STATUS , +and +.Sy SUSP +characters is not done. +This bit should be set when restarting system calls +that read from or write to a terminal +.Po +see +.Xr sigaction 2 +.Pc . +.Pp +If +.Dv TOSTOP +and +.Dv IEXTEN +are set, the signal +.Dv SIGTTOU +is sent to +a process that tries to write to its controlling terminal if it is not in the +foreground process group for that terminal. +This signal normally stops the process. +Otherwise, the output generated by that process is output to the +current output stream. +Processes that are blocking or ignoring +.Dv SIGTTOU +signals are excepted and allowed to produce output, if any. +.Pp +If +.Dv FLUSHO +and +.Dv IEXTEN +are set, data written to the terminal is +discarded. +This bit is set when the +.Sy FLUSH +character is typed. +A program can cancel the effect of typing the +.Sy FLUSH +character by clearing +.Dv FLUSHO . +.Pp +If +.Dv PENDIN +and +.Dv IEXTEN +are set, any input that has not yet been read +is reprinted when the next character arrives as input. +.Dv PENDIN +is then +automatically cleared. +.Pp +If +.Dv IEXTEN +is set, the following implementation-defined functions are +enabled: special characters ( +.Sy WERASE , +.Sy REPRINT , +.Sy DISCARD , +and +.Sy LNEXT ) +and local flags ( +.Dv TOSTOP , +.Dv ECHOCTL , +.Dv ECHOPRT , +.Dv ECHOKE , +.Dv FLUSHO , +and +.Dv PENDIN ) . +.Ss "Minimum and Timeout" +The +.Sy MIN +and +.Sy TIME +values were described previously, in the +subsection, +.Sy Non-canonical Mode Input Processing . +The initial value of +.Sy MIN +is 1, and the initial value of +.Sy TIME +is 0. +.Ss "Terminal Size" +The number of lines and columns on the terminal's display is specified in the +.Vt winsize +structure defined by +.In sys/termios.h +and includes the following members: +.Bd -literal -offset 2n +unsigned short ws_row; /* rows, in characters */ +unsigned short ws_col; /* columns, in characters */ +unsigned short ws_xpixel; /* horizontal size, in pixels */ +unsigned short ws_ypixel; /* vertical size, in pixels */ +.Ed +.Ss "Termio Structure" +The SunOS/SVR4 +.Vt termio +structure is used by some +.Fn ioctl Ns s ; +it is defined by +.In sys/termio.h +and includes the following members: +.Bd -literal -offset 2n +unsigned short c_iflag; /* input modes */ +unsigned short c_oflag; /* output modes */ +unsigned short c_cflag; /* control modes */ +unsigned short c_lflag; /* local modes */ +char c_line; /* line discipline */ +unsigned char c_cc[NCC]; /* control chars */ +.Ed +.Pp +The special control characters are defined by the array +.Fa c_cc . +The symbolic name +.Dv NCC +is the size of the Control-character array and is also +defined by +.In termio.h . +The relative positions, subscript names, and typical +default values for each function are as follows: +.Bl -column "Relative Positions" "Subscript Names" "Typical Default Values" +.It Relative Positions Ta Subscript Names Ta Typical Default Values +.It 0 Ta VINTR Ta EXT +.It 1 Ta VQUIT Ta FS +.It 2 Ta VERASE Ta DEL +.It 3 Ta VKILL Ta NAK +.It 4 Ta VEOF Ta EOT +.It 5 Ta VEOL Ta NUL +.It 6 Ta VEOL2 Ta NUL +.It 7 Ta Reserved Ta +.El +.Pp +The +.Sy MIN +values is stored in the +.Dv VMIN +element of the +.Fa c_cc +array; the +.Sy TIME +value is stored in the +.Dv VTIME +element of the +.Fa c_cc +array. +The +.Dv VMIN +element is the same element as the +.Dv VEOF +element; the +.Dv VTIME +element is the same element as the +.Dv VEOL +element. +.Pp +The calls that use the +.Va termio +structure only affect the flags and control +characters that can be stored in the +.Vt termio +structure; all other flags and control characters are unaffected. +.Ss "Modem Lines" +On special files representing serial ports, modem control lines can be read. +Control lines (if the underlying hardware supports it) may also be changed. +Status lines are read-only. +The following modem control and status lines may be +supported by a device; they are defined by +.In sys/termios.h : +.Pp +.Bl -tag -width "TIOCM_DTR" -compact -offset 2n +.It Dv TIOCM_LE +line enable +.It Dv TIOCM_DTR +data terminal ready +.It Dv TIOCM_RTS +request to send +.It Dv TIOCM_ST +secondary transmit +.It Dv TIOCM_SR +secondary receive +.It Dv TIOCM_CTS +clear to send +.It Dv TIOCM_CAR +carrier detect +.It Dv TIOCM_RNG +ring +.It Dv TIOCM_DSR +data set ready +.El +.Pp +.Dv TIOCM_CD +is a synonym for +.Dv TIOCM_CAR , +and +.Dv TIOCM_RI +is a synonym for +.Dv TIOCM_RNG . +Not all of these are necessarily supported by any +particular device; check the manual page for the device in question. +.Pp +The software carrier mode can be enabled or disabled using the +.Dv TIOCSSOFTCAR +.Fn ioctl . +If the software carrier flag for a line is off, +the line pays attention to the hardware carrier detect (DCD) signal. +The +.Sy tty +device associated with the line cannot be opened until +.Sy DCD +is asserted. +If the software carrier flag is on, the line behaves as if +.Sy DCD +is always asserted. +.Pp +The software carrier flag is usually turned on for locally connected terminals +or other devices, and is off for lines with modems. +.Pp +To be able to issue the +.Dv TIOCGSOFTCAR +and +.Dv TIOCSSOFTCAR +.Fn ioctl +calls, the +.Sy tty +line should be opened with +.Dv O_NDELAY +so that the +.Xr open 2 +will not wait for the carrier. +.Ss "Default Values" +The initial +.Vt termios +values upon driver open is configurable. +This is accomplished by setting the "ttymodes" property in the file +.Pa /kernel/drv/options.conf . +Since this property is assigned during system +initialization, any change to the "ttymodes" property will not take effect +until the next reboot. +The string value assigned to this property should be in +the same format as the output of the +.Xr stty 1 +command with the -g option. +.Pp +If this property is undefined, the following +.Vt termios +modes are in effect. +The initial input control value is +.Dv BRKINT , +.Dv ICRNL , +.Dv IXON , +.Dv IMAXBEL . +The initial output control value is +.Dv OPOST , +.Dv ONLCR , +.Dv TAB3 . +The initial hardware control value is +.Dv B9600 , +.Dv CS8 , +.Dv CREAD . +The initial line-discipline control value is +.Dv ISIG , +.Dv ICANON , +.Dv IEXTEN , +.Dv ECHO , +.Dv ECHOK , +.Dv ECHOE , +.Dv ECHOKE , +.Dv ECHOCTL . +.Sh IOCTLS +The +.Fn ioctl Ns s +supported by devices and +.Sy STREAMS +modules providing the +.Xr termios 3C +interface are listed below. +Some calls may not be supported by all devices or modules. +The functionality provided by these calls is also +available through the preferred function call interface specified on +.Nm termios . +.Bl -tag -width TIOCSSOFTCAR +.It Dv TCGETS +The argument is a pointer to a +.Vt termios +structure. +The current terminal parameters are fetched and stored into that structure. +.It Dv TCSETS +The argument is a pointer to a +.Vt termios +structure. +The current terminal parameters are set from the values stored in that structure. +The change is immediate. +.It Dv TCSETSW +The argument is a pointer to a +.Vt termios +structure. +The current terminal parameters are set from the values stored in that structure. +The change occurs after all characters queued for output have been transmitted. +This form should be used when changing parameters that affect output. +.It Dv TCSETSF +The argument is a pointer to a +.Vt termios +structure. +The current terminal parameters are set from the values stored in that structure. +The change occurs after all characters queued for output have been transmitted; +all characters queued for input are discarded and then the change occurs. +.It Dv TCGETA +The argument is a pointer to a +.Vt termio +structure. +The current terminal parameters are fetched, and those parameters that can be +stored in a +.Vt termio +structure are stored into that structure. +.It Dv TCSETA +The argument is a pointer to a +.Vt termio +structure. +Those terminal parameters that can be stored in a +.Vt termio +structure are set from the values stored in that structure. +The change is immediate. +.It Dv TCSETAW +The argument is a pointer to a +.Vt termio +structure. +Those terminal parameters that can be stored in a +.Vt termio +structure are set from +the values stored in that structure. +The change occurs after all characters queued for output have been transmitted. +This form should be used when changing parameters that affect output. +.It Dv TCSETAF +The argument is a pointer to a +.Vt termio +structure. +Those terminal parameters that can be stored in a +.Vt termio +structure are set from the values stored in that structure. +The change occurs after all characters queued +for output have been transmitted; all characters queued for input are discarded +and then the change occurs. +.It Dv TCSBRK +The argument is an +.Vt int +value. +Wait for the output to drain. +If the argument is +.Sy 0 , +then send a break (zero valued bits for 0\&.25 seconds). +.It Dv TCXONC +Start/stop control. +The argument is an +.Vt int +value. +If the argument is +.Sy 0 , +suspend output; if +.Sy 1 , +restart suspended output; if +.Sy 2 , +suspend input; if +.Sy 3 , +restart suspended input. +.It Dv TCFLSH +The argument is an +.Vt int +value. +If the argument is +.Sy 0 , +flush the input queue; if +.Sy 1 , +flush the output queue; if +.Sy 2 , +flush both the input and output queues. +.It Dv TIOCGPGRP +The argument is a pointer to a +.Vt pid_t . +Set the value of that +.Vt pid_t +to the process group +.Sy ID +of the foreground process group associated with the terminal. +See +.Xr termios 3C +for a description of +.Dv TCGETPGRP . +.It Dv TIOCSPGRP +The argument is a pointer to a +.Vt pid_t . +Associate the process group whose +process group +.Sy ID +is specified by the value of that +.Vt pid_t +with the terminal. +The new process group value must be in the range of valid process +group +.Sy ID +values. +Otherwise, the error +.Er EPERM +is returned. +.It Dv TIOCGSID +The argument is a pointer to a +.Vt pid_t . +The session ID of the terminal is fetched and stored in the +.Vt pid_t . +.It Dv TIOCGWINSZ +The argument is a pointer to a +.Vt winsize +structure. +The terminal driver's +notion of the terminal size is stored into that structure. +.It Dv TIOCSWINSZ +The argument is a pointer to a +.Vt winsize +structure. +The terminal driver's +notion of the terminal size is set from the values specified in that structure. +If the new sizes are different from the old sizes, a +.Dv SIGWINCH +signal is set to the process group of the terminal. +.It Dv TIOCMBIS +The argument is a pointer to an +.Vt int +whose value is a mask containing modem control lines to be turned on. +The control lines whose bits are set in +the argument are turned on; no other control lines are affected. +.It Dv TIOCMBIC +The argument is a pointer to an +.Vt int +whose value is a mask containing modem control lines to be turned off. +The control lines whose bits are set in +the argument are turned off; no other control lines are affected. +.It Dv TIOCMGET +The argument is a pointer to an +.Vt int . +The current state of the modem +status lines is fetched and stored in the +.Vt int +pointed to by the argument. +.It Dv TIOCMSET +The argument is a pointer to an +.Vt int +containing a new set of modem control lines. +The modem control lines are turned on or off, depending on +whether the bit for that mode is set or clear. +.It Dv TIOCSPPS +The argument is a pointer to an +.Vt int +that determines whether pulse-per-second event handling is to be enabled +(non-zero) or disabled (zero). +If a one-pulse-per-second reference clock is attached to the serial line's data +carrier detect input, the local system clock will be calibrated to it. +A clock with a high error, that is, a deviation of more than 25 microseconds +per tick, is ignored. +.It Dv TIOCGPPS +The argument is a pointer to an +.Vt int , +in which the state of the even handling is returned. +The +.Vt int +is set to a non-zero value if pulse-per-second (PPS) handling has been enabled. +Otherwise, it is set to zero. +.It Dv TIOCGSOFTCAR +The argument is a pointer to an +.Vt int +whose value is +.Sy 1 +or +.Sy 0 , +depending on whether the software carrier detect is turned on or off. +.It Dv TIOCSSOFTCAR +The argument is a pointer to an +.Vt int +whose value is +.Sy 1 +or +.Sy 0 . +The value of the integer should be +.Sy 0 +to turn off software carrier, or +.Sy 1 +to turn it on. +.It Dv TIOCGPPSEV +The argument is a pointer to a +.Vt "struct ppsclockev" . +This structure contains the following members: +.Bd -literal -offset 2n +struct timeval tv; +uint32_t serial; +.Ed +.Pp +.Fa tv +is the system clock timestamp when the event (pulse on the +.Sy DCD +pin) occurred. +.Fa serial +is the ordinal of the event, which each consecutive event +being assigned the next ordinal. +The first event registered gets a +.Fa serial +value of +.Sy 1 . +The +.Dv TIOCGPPSEV +returns the last event registered; multiple calls will persistently return the +same event until a new one is registered. +In addition to time stamping and saving the event, if it is of +one-second period and of consistently high accuracy, the local system clock +will automatically calibrate to it. +.El +.Sh FILES +Files in or under +.Pa /dev +.Sh SEE ALSO +.Xr stty 1 , +.Xr fork 2 , +.Xr getpgid 2 , +.Xr getsid 2 , +.Xr ioctl 2 , +.Xr setsid 2 , +.Xr sigaction 2 , +.Xr signal 3C , +.Xr tcsetpgrp 3C , +.Xr termios 3C , +.Xr signal.h 3HEAD , +.Xr streamio 4I |