BSD 4_4_Lite2 release

[unix-history] / usr / src / share / doc / psd / 05.sysman / 2.4.t

diff --git a/usr/src/share/doc/psd/05.sysman/2.4.t b/usr/src/share/doc/psd/05.sysman/2.4.t
index cd7dcb9..9fe4679 100644 (file)
--- a/usr/src/share/doc/psd/05.sysman/2.4.t
+++ b/usr/src/share/doc/psd/05.sysman/2.4.t
@@ -1,4 +1,4 @@
-.\" Copyright (c) 1983, 1993
+.\" Copyright (c) 1983, 1993, 1994

 .\"    The Regents of the University of California.  All rights reserved.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
 .\"    The Regents of the University of California.  All rights reserved.
 .\"
 .\" Redistribution and use in source and binary forms, with or without


@@ -29,142 +29,142 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"

-.\"    @(#)2.4.t       8.1 (Berkeley) 6/8/93
+.\"    @(#)2.4.t       8.5 (Berkeley) 6/1/94

 .\"
 .\"

-.sh "Terminals and Devices
-.NH 3
-Terminals
+.Sh 2 "Terminals and Devices
+.Sh 3 "Terminals

 .PP
 .PP

-Terminals support \fIread\fP and \fIwrite\fP I/O operations,
-as well as a collection of terminal specific \fIioctl\fP operations,
+Terminals support
+.Fn read
+and
+.Fn write
+I/O operations,
+as well as a collection of terminal specific
+.Fn ioctl
+operations,

 to control input character interpretation and editing,
 and output format and delays.
 to control input character interpretation and editing,
 and output format and delays.

-.NH 4
-Terminal input
+.PP
+A terminal may be used as a controlling terminal (login terminal)
+for a login session.
+A controlling terminal is associated with a session (see section
+.Xr 1.1.4 ).
+A controlling terminal has a foreground process group, which must be
+a member of the session with which the terminal is associated (see section
+.Xr 1.1.5 ).
+Members of the foreground process group are allowed to read from and write to
+the terminal and change the terminal settings; other process groups from
+the session may be stopped upon attempts to do these operations.
+.PP
+A session leader allocates a terminal
+as the controlling terminal for its session using the ioctl
+.DS
+ioctl(fd, TIOCSCTTY, NULL);
+int fd;
+.DE
+Only a session leader may acquire a controlling terminal.
+.ne 1i
+.Sh 4 "Terminal input

 .PP
 Terminals are handled according to the underlying communication
 characteristics such as baud rate and required delays,
 and a set of software parameters.
 .PP
 Terminals are handled according to the underlying communication
 characteristics such as baud rate and required delays,
 and a set of software parameters.

-.NH 5
-Input modes
+These parameters are described in the \fItermios\fP structure
+maintained by the kernel for each terminal line:
+.DS
+.TS
+l s s s
+l l l l.
+struct termios {
+       tcflag_t        c_iflag;        /* input flags */
+       tcflag_t        c_oflag;        /* output flags */
+       tcflag_t        c_cflag;        /* control flags */
+       tcflag_t        c_lflag;        /* local flags */
+       cc_t    c_cc[NCCS];     /* control chars */
+       long    c_ispeed;       /* input speed */
+       long    c_ospeed;       /* output speed */
+};
+.TE
+.DE
+The \fItermios\fP structure is set and retrieved using the
+.Fn tcsetattr
+and
+.Fn tcgetattr
+functions.

 .PP
 .PP

-A terminal is in one of three possible modes: \fIraw\fP, \fIcbreak\fP,
-or \fIcooked\fP.
-In raw mode all input is passed through to the
+Two general kinds of input processing are available, determined by
+whether the terminal device file is in canonical mode or noncanonical
+mode. Additionally, input characters are processed according to the
+\fIc_iflag\fP and \fIc_lflag\fP fields.
+Such processing can include echoing, which
+in general means transmitting input characters immediately back to the
+terminal when they are received from the terminal.
+Non-graphic ASCII input characters may be echoed as a two-character
+printable representation, ``^character.''
+.PP
+In canonical mode input processing,
+terminal input is processed in units of lines.
+A line is delimited by a newline character (NL),
+an end-of-file (EOF) character, or an end-of-line (EOL) character.
+Input is presented on a line-by-line basis.
+Using this mode means that a read request will not return
+until an entire line has been typed,
+or a signal has been received.
+Also, no matter how many bytes are requested
+in the read call, at most one line is returned.
+It is not, however, necessary to read a whole line at once;
+any number of bytes, even one, may
+be requested in a read without losing information.
+.PP
+When the terminal is in canonical mode, editing of an input line
+is performed.  Editing facilities allow deletion of the previous
+character or word, or deletion of the current input line. 
+In addition,
+a special character may be used to reprint the current input line.
+Certain other characters are also interpreted specially.
+Flow control is provided by the \fIstop output\fP
+and \fIstart output\fP control characters.
+Output may be flushed with the \fIflush output\fP character;
+and the \fIliteral character\fP may be used to force the following
+character into the input line, regardless of any special meaning
+it may have.
+.PP
+In noncanonical mode input processing, input bytes are not assembled into
+lines, and erase and kill processing does not occur.
+All input is passed through to the

 reading process immediately and without interpretation.
 reading process immediately and without interpretation.

-In cbreak mode, the handler interprets input only by looking
+Signals and flow control may be enabled; here
+the handler interprets input only by looking

 for characters that cause interrupts or output flow control;
 for characters that cause interrupts or output flow control;

-all other characters are made available as in raw mode.
-In cooked mode, input
-is processed to provide standard line-oriented local editing functions,
-and input is presented on a line-by-line basis.
-.NH 5
-Interrupt characters
+all other characters are made available.

 .PP
 .PP

-Interrupt characters are interpreted by the terminal handler only in
-cbreak and cooked modes, and
+When interrupt characters are being interpreted
+by the terminal handler they

 cause a software interrupt to be sent to all processes in the process
 cause a software interrupt to be sent to all processes in the process

-group associated with the terminal.  Interrupt characters exist
-to send SIGINT
+group associated with the terminal.
+Interrupt characters exist to send SIGINT

 and SIGQUIT signals,
 and to stop a process group
 with the SIGTSTP signal either immediately, or when
 all input up to the stop character has been read.
 and SIGQUIT signals,
 and to stop a process group
 with the SIGTSTP signal either immediately, or when
 all input up to the stop character has been read.

-.NH 5
-Line editing
-.PP
-When the terminal is in cooked mode, editing of an input line
-is performed.  Editing facilities allow deletion of the previous
-character or word, or deletion of the current input line. 
-In addition, a special character may be used to reprint the current
-input line after some number of editing operations have been applied.
-.PP
-Certain other characters are interpreted specially when a process is
-in cooked mode.  The \fIend of line\fP character determines
-the end of an input record.  The \fIend of file\fP character simulates
-an end of file occurrence on terminal input.  Flow control is provided
-by \fIstop output\fP and \fIstart output\fP control characters.  Output
-may be flushed with the \fIflush output\fP character; and a \fIliteral
-character\fP may be used to force literal input of the immediately
-following character in the input line.
-.PP
-Input characters may be echoed to the terminal as they are received.
-Non-graphic ASCII input characters may be echoed as a two-character
-printable representation, ``^character.''
-.NH 4
-Terminal output
+.Sh 4 "Terminal output

 .PP
 On output, the terminal handler provides some simple formatting services.
 These include converting the carriage return character to the
 two character return-linefeed sequence,
 inserting delays after certain standard control characters,
 .PP
 On output, the terminal handler provides some simple formatting services.
 These include converting the carriage return character to the
 two character return-linefeed sequence,
 inserting delays after certain standard control characters,

-expanding tabs, and providing translations
-for upper-case only terminals.
-.NH 4
-Terminal control operations
-.PP
-When a terminal is first opened it is initialized to a standard
-state and configured with a set of standard control, editing,
-and interrupt characters.  A process
-may alter this configuration with certain
-control operations, specifying parameters in a standard structure:\(dg
-.FS
-\(dg The control interface described here is an internal interface only
-in 4.3BSD.  Future releases will probably use a modified interface
-based on currently-proposed standards.
-.FE
-.DS
-._f
-struct ttymode {
-       short   tt_ispeed;      /* input speed */
-       int     tt_iflags;      /* input flags */
-       short   tt_ospeed;      /* output speed */
-       int     tt_oflags;      /* output flags */
-};
-.DE
-and ``special characters'' are specified with the 
-\fIttychars\fP structure,
-.DS
-._f
-struct ttychars {
-       char    tc_erasec;      /* erase char */
-       char    tc_killc;       /* erase line */
-       char    tc_intrc;       /* interrupt */
-       char    tc_quitc;       /* quit */
-       char    tc_startc;      /* start output */
-       char    tc_stopc;       /* stop output */
-       char    tc_eofc;        /* end-of-file */
-       char    tc_brkc;        /* input delimiter (like nl) */
-       char    tc_suspc;       /* stop process signal */
-       char    tc_dsuspc;      /* delayed stop process signal */
-       char    tc_rprntc;      /* reprint line */
-       char    tc_flushc;      /* flush output (toggles) */
-       char    tc_werasc;      /* word erase */
-       char    tc_lnextc;      /* literal next character */
-};
-.DE
-.NH 4
-Terminal hardware support
-.PP
-The terminal handler allows a user to access basic
-hardware related functions; e.g. line speed,
-modem control, parity, and stop bits.  A special signal,
-SIGHUP, is automatically
-sent to processes in a terminal's process
-group when a carrier transition is detected.  This is
-normally associated with a user hanging up on a modem
-controlled terminal line.
-.NH 3
-Structured devices
+and expanding tabs.
+.pl +1
+.Sh 3 "Structured devices

 .PP
 .PP

-Structures devices are typified by disks and magnetic
+Structured devices are typified by disks and magnetic

 tapes, but may represent any random-access device.
 The system performs read-modify-write type buffering actions on block
 tapes, but may represent any random-access device.
 The system performs read-modify-write type buffering actions on block

-devices to allow them to be read and written in a totally random
-access fashion like ordinary files.
-File systems are normally created in block devices.
-.NH 3
-Unstructured devices
+devices to allow them to be read and written in random access
+fashion like ordinary files.
+Filesystems are normally mounted on block devices.
+.pl -1
+.Sh 3 "Unstructured devices

 .PP
 Unstructured devices are those devices which
 do not support block structure.  Familiar unstructured devices
 .PP
 Unstructured devices are those devices which
 do not support block structure.  Familiar unstructured devices