'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\"
-'\" CVS: @(#) $Id: TraceCmd.3,v 1.5 2002/07/01 18:24:39 jenglish Exp $
-'\"
-'\" The definitions below are for supplemental macros used in Tcl/Tk
-'\" manual entries.
-'\"
-'\" .AP type name in/out ?indent?
-'\" Start paragraph describing an argument to a library procedure.
-'\" type is type of argument (int, etc.), in/out is either "in", "out",
-'\" or "in/out" to describe whether procedure reads or modifies arg,
-'\" and indent is equivalent to second arg of .IP (shouldn't ever be
-'\" needed; use .AS below instead)
-'\"
-'\" .AS ?type? ?name?
-'\" Give maximum sizes of arguments for setting tab stops. Type and
-'\" name are examples of largest possible arguments that will be passed
-'\" to .AP later. If args are omitted, default tab stops are used.
-'\"
-'\" .BS
-'\" Start box enclosure. From here until next .BE, everything will be
-'\" enclosed in one large box.
-'\"
-'\" .BE
-'\" End of box enclosure.
-'\"
-'\" .CS
-'\" Begin code excerpt.
-'\"
-'\" .CE
-'\" End code excerpt.
-'\"
-'\" .VS ?version? ?br?
-'\" Begin vertical sidebar, for use in marking newly-changed parts
-'\" of man pages. The first argument is ignored and used for recording
-'\" the version when the .VS was added, so that the sidebars can be
-'\" found and removed when they reach a certain age. If another argument
-'\" is present, then a line break is forced before starting the sidebar.
-'\"
-'\" .VE
-'\" End of vertical sidebar.
-'\"
-'\" .DS
-'\" Begin an indented unfilled display.
-'\"
-'\" .DE
-'\" End of indented unfilled display.
-'\"
-'\" .SO
-'\" Start of list of standard options for a Tk widget. The
-'\" options follow on successive lines, in four columns separated
-'\" by tabs.
-'\"
-'\" .SE
-'\" End of list of standard options for a Tk widget.
-'\"
-'\" .OP cmdName dbName dbClass
-'\" Start of description of a specific option. cmdName gives the
-'\" option's name as specified in the class command, dbName gives
-'\" the option's name in the option database, and dbClass gives
-'\" the option's class in the option database.
-'\"
-'\" .UL arg1 arg2
-'\" Print arg1 underlined, then print arg2 normally.
-'\"
-'\" RCS: @(#) $Id: man.macros,v 1.4 2000/08/25 06:18:32 ericm Exp $
-'\"
-'\" # Set up traps and other miscellaneous stuff for Tcl/Tk man pages.
+.TH Tcl_TraceCommand 3 7.4 Tcl "Tcl Library Procedures"
+.\" The -*- nroff -*- definitions below are for supplemental macros used
+.\" in Tcl/Tk manual entries.
+.\"
+.\" .AP type name in/out ?indent?
+.\" Start paragraph describing an argument to a library procedure.
+.\" type is type of argument (int, etc.), in/out is either "in", "out",
+.\" or "in/out" to describe whether procedure reads or modifies arg,
+.\" and indent is equivalent to second arg of .IP (shouldn't ever be
+.\" needed; use .AS below instead)
+.\"
+.\" .AS ?type? ?name?
+.\" Give maximum sizes of arguments for setting tab stops. Type and
+.\" name are examples of largest possible arguments that will be passed
+.\" to .AP later. If args are omitted, default tab stops are used.
+.\"
+.\" .BS
+.\" Start box enclosure. From here until next .BE, everything will be
+.\" enclosed in one large box.
+.\"
+.\" .BE
+.\" End of box enclosure.
+.\"
+.\" .CS
+.\" Begin code excerpt.
+.\"
+.\" .CE
+.\" End code excerpt.
+.\"
+.\" .VS ?version? ?br?
+.\" Begin vertical sidebar, for use in marking newly-changed parts
+.\" of man pages. The first argument is ignored and used for recording
+.\" the version when the .VS was added, so that the sidebars can be
+.\" found and removed when they reach a certain age. If another argument
+.\" is present, then a line break is forced before starting the sidebar.
+.\"
+.\" .VE
+.\" End of vertical sidebar.
+.\"
+.\" .DS
+.\" Begin an indented unfilled display.
+.\"
+.\" .DE
+.\" End of indented unfilled display.
+.\"
+.\" .SO ?manpage?
+.\" Start of list of standard options for a Tk widget. The manpage
+.\" argument defines where to look up the standard options; if
+.\" omitted, defaults to "options". The options follow on successive
+.\" lines, in three columns separated by tabs.
+.\"
+.\" .SE
+.\" End of list of standard options for a Tk widget.
+.\"
+.\" .OP cmdName dbName dbClass
+.\" Start of description of a specific option. cmdName gives the
+.\" option's name as specified in the class command, dbName gives
+.\" the option's name in the option database, and dbClass gives
+.\" the option's class in the option database.
+.\"
+.\" .UL arg1 arg2
+.\" Print arg1 underlined, then print arg2 normally.
+.\"
+.\" .QW arg1 ?arg2?
+.\" Print arg1 in quotes, then arg2 normally (for trailing punctuation).
+.\"
+.\" .PQ arg1 ?arg2?
+.\" Print an open parenthesis, arg1 in quotes, then arg2 normally
+.\" (for trailing punctuation) and then a closing parenthesis.
+.\"
+.\" # Set up traps and other miscellaneous stuff for Tcl/Tk man pages.
.if t .wh -1.3i ^B
.nr ^l \n(.l
.ad b
-'\" # Start an argument description
+.\" # Start an argument description
.de AP
.ie !"\\$4"" .TP \\$4
.el \{\
.\}
.ta \\n()Au \\n()Bu
.ie !"\\$3"" \{\
-\&\\$1 \\fI\\$2\\fP (\\$3)
+\&\\$1 \\fI\\$2\\fP (\\$3)
.\".b
.\}
.el \{\
.\}
.\}
..
-'\" # define tabbing values for .AP
+.\" # define tabbing values for .AP
.de AS
.nr )A 10n
.if !"\\$1"" .nr )A \\w'\\$1'u+3n
.nr )C \\n()Bu+\\w'(in/out)'u+2n
..
.AS Tcl_Interp Tcl_CreateInterp in/out
-'\" # BS - start boxed text
-'\" # ^y = starting y location
-'\" # ^b = 1
+.\" # BS - start boxed text
+.\" # ^y = starting y location
+.\" # ^b = 1
.de BS
.br
.mk ^y
.if n \l'\\n(.lu\(ul'
.if n .fi
..
-'\" # BE - end boxed text (draw box now)
+.\" # BE - end boxed text (draw box now)
.de BE
.nf
.ti 0
.br
.nr ^b 0
..
-'\" # VS - start vertical sidebar
-'\" # ^Y = starting y location
-'\" # ^v = 1 (for troff; for nroff this doesn't matter)
+.\" # VS - start vertical sidebar
+.\" # ^Y = starting y location
+.\" # ^v = 1 (for troff; for nroff this doesn't matter)
.de VS
.if !"\\$2"" .br
.mk ^Y
.ie n 'mc \s12\(br\s0
.el .nr ^v 1u
..
-'\" # VE - end of vertical sidebar
+.\" # VE - end of vertical sidebar
.de VE
.ie n 'mc
.el \{\
.\}
.nr ^v 0
..
-'\" # Special macro to handle page bottom: finish off current
-'\" # box/sidebar if in box/sidebar mode, then invoked standard
-'\" # page bottom macro.
+.\" # Special macro to handle page bottom: finish off current
+.\" # box/sidebar if in box/sidebar mode, then invoked standard
+.\" # page bottom macro.
.de ^B
.ev 2
'ti 0
.mk ^Y
.\}
..
-'\" # DS - begin display
+.\" # DS - begin display
.de DS
.RS
.nf
.sp
..
-'\" # DE - end display
+.\" # DE - end display
.de DE
.fi
.RE
.sp
..
-'\" # SO - start of list of standard options
+.\" # SO - start of list of standard options
.de SO
+'ie '\\$1'' .ds So \\fBoptions\\fR
+'el .ds So \\fB\\$1\\fR
.SH "STANDARD OPTIONS"
.LP
.nf
.ta 5.5c 11c
.ft B
..
-'\" # SE - end of list of standard options
+.\" # SE - end of list of standard options
.de SE
.fi
.ft R
.LP
-See the \\fBoptions\\fR manual entry for details on the standard options.
+See the \\*(So manual entry for details on the standard options.
..
-'\" # OP - start of full description for a single option
+.\" # OP - start of full description for a single option
.de OP
.LP
.nf
.fi
.IP
..
-'\" # CS - begin code excerpt
+.\" # CS - begin code excerpt
.de CS
.RS
.nf
.ta .25i .5i .75i 1i
..
-'\" # CE - end code excerpt
+.\" # CE - end code excerpt
.de CE
.fi
.RE
..
+.\" # UL - underline word
.de UL
\\$1\l'|0\(ul'\\$2
..
-.TH Tcl_TraceCommand 3 7.4 Tcl "Tcl Library Procedures"
+.\" # QW - apply quotation marks to word
+.de QW
+.ie '\\*(lq'"' ``\\$1''\\$2
+.\"" fix emacs highlighting
+.el \\*(lq\\$1\\*(rq\\$2
+..
+.\" # PQ - apply parens and quotation marks to word
+.de PQ
+.ie '\\*(lq'"' (``\\$1''\\$2)\\$3
+.\"" fix emacs highlighting
+.el (\\*(lq\\$1\\*(rq\\$2)\\$3
+..
+.\" # QR - quoted range
+.de QR
+.ie '\\*(lq'"' ``\\$1''\\-``\\$2''\\$3
+.\"" fix emacs highlighting
+.el \\*(lq\\$1\\*(rq\\-\\*(lq\\$2\\*(rq\\$3
+..
+.\" # MT - "empty" string
+.de MT
+.QW ""
+..
.BS
.SH NAME
Tcl_CommandTraceInfo, Tcl_TraceCommand, Tcl_UntraceCommand \- monitor renames and deletes of a command
.AS Tcl_CommandTraceProc prevClientData
.AP Tcl_Interp *interp in
Interpreter containing the command.
-.AP "CONST char" *cmdName in
+.AP "const char" *cmdName in
Name of command.
.AP int flags in
-OR-ed collection of the value TCL_TRACE_RENAME and TCL_TRACE_DELETE.
+OR'ed collection of the values \fBTCL_TRACE_RENAME\fR and
+\fBTCL_TRACE_DELETE\fR.
.AP Tcl_CommandTraceProc *proc in
Procedure to call when specified operations occur to \fIcmdName\fR.
.AP ClientData clientData in
so this call will return information about next trace. If NULL, this
call will return information about first trace.
.BE
-
.SH DESCRIPTION
.PP
\fBTcl_TraceCommand\fR allows a C procedure to monitor operations
performed on a Tcl command, so that the C procedure is invoked
whenever the command is renamed or deleted. If the trace is created
-successfully then \fBTcl_TraceCommand\fR returns TCL_OK. If an error
+successfully then \fBTcl_TraceCommand\fR returns \fBTCL_OK\fR. If an error
occurred (e.g. \fIcmdName\fR specifies a non-existent command) then
-TCL_ERROR is returned and an error message is left in the
+\fBTCL_ERROR\fR is returned and an error message is left in the
interpreter's result.
.PP
The \fIflags\fR argument to \fBTcl_TraceCommand\fR indicates when the
-trace procedure is to be invoked. It consists of an OR-ed combination
+trace procedure is to be invoked. It consists of an OR'ed combination
of any of the following values:
.TP
\fBTCL_TRACE_RENAME\fR
Whenever one of the specified operations occurs to the command,
\fIproc\fR will be invoked. It should have arguments and result that
match the type \fBTcl_CommandTraceProc\fR:
+.PP
.CS
-typedef void Tcl_CommandTraceProc(
- ClientData \fIclientData\fR,
+typedef void \fBTcl_CommandTraceProc\fR(
+ ClientData \fIclientData\fR,
Tcl_Interp *\fIinterp\fR,
- CONST char *\fIoldName\fR,
- CONST char *\fInewName\fR,
+ const char *\fIoldName\fR,
+ const char *\fInewName\fR,
int \fIflags\fR);
.CE
+.PP
The \fIclientData\fR and \fIinterp\fR parameters will have the same
values as those passed to \fBTcl_TraceCommand\fR when the trace was
created. \fIClientData\fR typically points to an application-specific
\fIOldName\fR gives the name of the command being renamed, and
\fInewName\fR gives the name that the command is being renamed to (or
an empty string or NULL when the command is being deleted.)
-\fIFlags\fR is an OR-ed combination of bits potentially providing
-several pieces of information. One of the bits TCL_TRACE_RENAME and
-TCL_TRACE_DELETE will be set in \fIflags\fR to indicate which
+\fIFlags\fR is an OR'ed combination of bits potentially providing
+several pieces of information. One of the bits \fBTCL_TRACE_RENAME\fR and
+\fBTCL_TRACE_DELETE\fR will be set in \fIflags\fR to indicate which
operation is being performed on the command. The bit
-TCL_TRACE_DESTROYED will be set in \fIflags\fR if the trace is about
+\fBTCL_TRACE_DESTROYED\fR will be set in \fIflags\fR if the trace is about
to be destroyed; this information may be useful to \fIproc\fR so that
it can clean up its own internal data structures (see the section
-TCL_TRACE_DESTROYED below for more details). Lastly, the bit
-TCL_INTERP_DESTROYED will be set if the entire interpreter is being
-destroyed. When this bit is set, \fIproc\fR must be especially
-careful in the things it does (see the section TCL_INTERP_DESTROYED
-below).
+\fBTCL_TRACE_DESTROYED\fR below for more details). Because the
+deletion of commands can take place as part of the deletion of the interp
+that contains them, \fIproc\fR must be careful about checking what
+the passed in \fIinterp\fR value can be called upon to do.
+The routine \fBTcl_InterpDeleted\fR is an important tool for this.
+When \fBTcl_InterpDeleted\fR returns 1, \fIproc\fR will not be able
+to invoke any scripts in \fIinterp\fR. The function of \fIproc\fR
+in that circumstance is limited to the cleanup of its own data structures.
.PP
\fBTcl_UntraceCommand\fR may be used to remove a trace. If the
command specified by \fIinterp\fR, \fIcmdName\fR, and \fIflags\fR has
If the \fIprevClientData\fR argument is NULL then the return
value corresponds to the first (most recently created) matching
trace, or NULL if there are no matching traces.
-If the \fIprevClientData\fR argument isn't NULL, then it should
+If the \fIprevClientData\fR argument is not NULL, then it should
be the return value from a previous call to \fBTcl_CommandTraceInfo\fR.
In this case, the new return value will correspond to the next
matching trace after the one whose \fIclientData\fR matches
or if there are no more matching traces after it.
This mechanism makes it possible to step through all of the
traces for a given command that have the same \fIproc\fR.
-
.SH "CALLING COMMANDS DURING TRACES"
.PP
During rename traces, the command being renamed is visible with both
names simultaneously, and the command still exists during delete
-traces (if TCL_INTERP_DESTROYED is not set). However, there is no
+traces, unless the interp that contains it is being deleted.
+However, there is no
mechanism for signaling that an error occurred in a trace procedure,
so great care should be taken that errors do not get silently lost.
-
.SH "MULTIPLE TRACES"
.PP
It is possible for multiple traces to exist on the same command.
that renaming takes precedence over the one that triggered the trace
and the collection of traces will not be reexecuted; if several traces
rename the command, the last renaming takes precedence.
-
.SH "TCL_TRACE_DESTROYED FLAG"
.PP
-In a delete callback to \fIproc\fR, the TCL_TRACE_DESTROYED bit
+In a delete callback to \fIproc\fR, the \fBTCL_TRACE_DESTROYED\fR bit
is set in \fIflags\fR.
-
-'\" Perhaps need some more comments here? - DKF
-
-.SH "TCL_INTERP_DESTROYED"
-.PP
-When an interpreter is destroyed, unset traces are called for
-all of its commands.
-The TCL_INTERP_DESTROYED bit will be set in the \fIflags\fR
-argument passed to the trace procedures.
-Trace procedures must be extremely careful in what they do if
-the TCL_INTERP_DESTROYED bit is set.
-It is not safe for the procedures to invoke any Tcl procedures
-on the interpreter, since its state is partially deleted.
-All that trace procedures should do under these circumstances is
-to clean up and free their own internal data structures.
-
-.SH BUGS
-.PP
-Tcl doesn't do any error checking to prevent trace procedures
-from misusing the interpreter during traces with TCL_INTERP_DESTROYED
-set.
-
+.\" Perhaps need some more comments here? - DKF
.SH KEYWORDS
clientData, trace, command