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diff --git a/man1p/talk.1p b/man1p/talk.1p new file mode 100644 index 000000000..b6a101a4d --- /dev/null +++ b/man1p/talk.1p @@ -0,0 +1,278 @@ +.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved +.TH "TALK" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual" +.\" talk +.SH NAME +talk \- talk to another user +.SH SYNOPSIS +.LP +\fBtalk\fP \fIaddress\fP \fB[\fP\fIterminal\fP\fB]\fP\fB\fP +.SH DESCRIPTION +.LP +The \fItalk\fP utility is a two-way, screen-oriented communication +program. +.LP +When first invoked, \fItalk\fP shall send a message similar to: +.sp +.RS +.nf + +\fBMessage from <\fP\fIunspecified string\fP\fB> +talk: connection requested by\fP \fIyour_address\fP\fBtalk: respond with: talk\fP \fIyour_address\fP +.fi +.RE +.LP +to the specified \fIaddress\fP. At this point, the recipient of the +message can reply by typing: +.sp +.RS +.nf + +\fBtalk\fP \fIyour_address\fP +.fi +.RE +.LP +Once communication is established, the two parties can type simultaneously, +with their output displayed in separate regions of +the screen. Characters shall be processed as follows: +.IP " *" 3 +Typing the alert character shall alert the recipient's terminal. +.LP +.IP " *" 3 +Typing <control>-L shall cause the sender's screen regions to be refreshed. +.LP +.IP " *" 3 +Typing the erase and kill characters shall affect the sender's terminal +in the manner described by the \fBtermios\fP interface +in the Base Definitions volume of IEEE\ Std\ 1003.1-2001, Chapter +11, General +Terminal Interface. +.LP +.IP " *" 3 +Typing the interrupt or end-of-file characters shall terminate the +local \fItalk\fP utility. Once the \fItalk\fP session has +been terminated on one side, the other side of the \fItalk\fP session +shall be notified that the \fItalk\fP session has been +terminated and shall be able to do nothing except exit. +.LP +.IP " *" 3 +Typing characters from \fILC_CTYPE\fP classifications \fBprint\fP +or \fBspace\fP shall cause those characters to be sent to +the recipient's terminal. +.LP +.IP " *" 3 +When and only when the \fIstty\fP \fBiexten\fP local mode is enabled, +the existence and +processing of additional special control characters and multi-byte +or single-byte functions shall be implementation-defined. +.LP +.IP " *" 3 +Typing other non-printable characters shall cause implementation-defined +sequences of printable characters to be sent to the +recipient's terminal. +.LP +.LP +Permission to be a recipient of a \fItalk\fP message can be denied +or granted by use of the \fImesg\fP utility. However, a user's privilege +may further constrain the domain of accessibility of +other users' terminals. The \fItalk\fP utility shall fail when the +user lacks the appropriate privileges to perform the requested +action. +.LP +Certain block-mode terminals do not have all the capabilities necessary +to support the simultaneous exchange of messages +required for \fItalk\fP. When this type of exchange cannot be supported +on such terminals, the implementation may support an +exchange with reduced levels of simultaneous interaction or it may +report an error describing the terminal-related deficiency. +.SH OPTIONS +.LP +None. +.SH OPERANDS +.LP +The following operands shall be supported: +.TP 7 +\fIaddress\fP +The recipient of the \fItalk\fP session. One form of \fIaddress\fP +is the <\fIuser\ name\fP>, as returned by the +\fIwho\fP utility. Other address formats and how they are handled +are unspecified. +.TP 7 +\fIterminal\fP +If the recipient is logged in more than once, the \fIterminal\fP argument +can be used to indicate the appropriate terminal +name. If \fIterminal\fP is not specified, the \fItalk\fP message shall +be displayed on one or more accessible terminals in use by +the recipient. The format of \fIterminal\fP shall be the same as that +returned by the \fIwho\fP utility. +.sp +.SH STDIN +.LP +Characters read from standard input shall be copied to the recipient's +terminal in an unspecified manner. If standard input is +not a terminal, talk shall write a diagnostic message and exit with +a non-zero status. +.SH INPUT FILES +.LP +None. +.SH ENVIRONMENT VARIABLES +.LP +The following environment variables shall affect the execution of +\fItalk\fP: +.TP 7 +\fILANG\fP +Provide a default value for the internationalization variables that +are unset or null. (See the Base Definitions volume of +IEEE\ Std\ 1003.1-2001, Section 8.2, Internationalization Variables +for +the precedence of internationalization variables used to determine +the values of locale categories.) +.TP 7 +\fILC_ALL\fP +If set to a non-empty string value, override the values of all the +other internationalization variables. +.TP 7 +\fILC_CTYPE\fP +Determine the locale for the interpretation of sequences of bytes +of text data as characters (for example, single-byte as +opposed to multi-byte characters in arguments and input files). If +the recipient's locale does not use an \fILC_CTYPE\fP +equivalent to the sender's, the results are undefined. +.TP 7 +\fILC_MESSAGES\fP +Determine the locale that should be used to affect the format and +contents of diagnostic messages written to standard error and +informative messages written to standard output. +.TP 7 +\fINLSPATH\fP +Determine the location of message catalogs for the processing of \fILC_MESSAGES +\&.\fP +.TP 7 +\fITERM\fP +Determine the name of the invoker's terminal type. If this variable +is unset or null, an unspecified default terminal type +shall be used. +.sp +.SH ASYNCHRONOUS EVENTS +.LP +When the \fItalk\fP utility receives a SIGINT signal, the utility +shall terminate and exit with a zero status. It shall take +the standard action for all other signals. +.SH STDOUT +.LP +If standard output is a terminal, characters copied from the recipient's +standard input may be written to standard output. +Standard output also may be used for diagnostic messages. If standard +output is not a terminal, \fItalk\fP shall exit with a +non-zero status. +.SH STDERR +.LP +None. +.SH OUTPUT FILES +.LP +None. +.SH EXTENDED DESCRIPTION +.LP +None. +.SH EXIT STATUS +.LP +The following exit values shall be returned: +.TP 7 +\ 0 +Successful completion. +.TP 7 +>0 +An error occurred or \fItalk\fP was invoked on a terminal incapable +of supporting it. +.sp +.SH CONSEQUENCES OF ERRORS +.LP +Default. +.LP +\fIThe following sections are informative.\fP +.SH APPLICATION USAGE +.LP +Because the handling of non-printable, non- <space>s is tied to the +\fIstty\fP +description of \fBiexten\fP, implementation extensions within the +terminal driver can be accessed. For example, some +implementations provide line editing functions with certain control +character sequences. +.SH EXAMPLES +.LP +None. +.SH RATIONALE +.LP +The \fIwrite\fP utility was included in this volume of IEEE\ Std\ 1003.1-2001 +since it can be implemented on all terminal types. The \fItalk\fP +utility, which cannot be implemented on certain terminals, was +considered to be a "better" communications interface. Both of these +programs are in widespread use on historical implementations. +Therefore, both utilities have been specified. +.LP +All references to networking abilities (\fItalk\fPing to a user on +another system) were removed as being outside the scope of +this volume of IEEE\ Std\ 1003.1-2001. +.LP +Historical BSD and System V versions of \fItalk\fP terminate both +of the conversations when either user breaks out of the +session. This can lead to adverse consequences if a user unwittingly +continues to enter text that is interpreted by the shell when +the other terminates the session. Therefore, the version of \fItalk\fP +specified by this volume of IEEE\ Std\ 1003.1-2001 +requires both users to terminate their end of the session explicitly. +.LP +Only messages sent to the terminal of the invoking user can be internationalized +in any way: +.IP " *" 3 +The original "Message from <\fIunspecified string\fP> ..." message +sent to the terminal of the recipient cannot be +internationalized because the environment of the recipient is as yet +inaccessible to the \fItalk\fP utility. The environment of +the invoking party is irrelevant. +.LP +.IP " *" 3 +Subsequent communication between the two parties cannot be internationalized +because the two parties may specify different +languages in their environment (and non-portable characters cannot +be mapped from one language to another). +.LP +.IP " *" 3 +Neither party can be required to communicate in a language other than +C and/or the one specified by their environment because +unavailable terminal hardware support (for example, fonts) may be +required. +.LP +.LP +The text in the STDOUT section reflects the usage of the verb "display" +in this section; some \fItalk\fP implementations +actually use standard output to write to the terminal, but this volume +of IEEE\ Std\ 1003.1-2001 does not require that to +be the case. +.LP +The format of the terminal name is unspecified, but the descriptions +of \fIps\fP, +\fItalk\fP, \fIwho\fP, and \fIwrite\fP require that +they all use or accept the same format. +.LP +The handling of non-printable characters is partially implementation-defined +because the details of mapping them to printable +sequences is not needed by the user. Historical implementations, for +security reasons, disallow the transmission of non-printable +characters that may send commands to the other terminal. +.SH FUTURE DIRECTIONS +.LP +None. +.SH SEE ALSO +.LP +\fImesg\fP , \fIstty\fP , \fIwho\fP , \fIwrite\fP , the Base Definitions +volume of IEEE\ Std\ 1003.1-2001, Chapter 11, General Terminal Interface +.SH COPYRIGHT +Portions of this text are reprinted and reproduced in electronic form +from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology +-- Portable Operating System Interface (POSIX), The Open Group Base +Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of +Electrical and Electronics Engineers, Inc and The Open Group. In the +event of any discrepancy between this version and the original IEEE and +The Open Group Standard, the original IEEE and The Open Group Standard +is the referee document. The original Standard can be obtained online at +http://www.opengroup.org/unix/online.html . |