diff options
Diffstat (limited to 'doc/trace.n')
| -rw-r--r-- | doc/trace.n | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/doc/trace.n b/doc/trace.n index 9d40123..940a1e9 100644 --- a/doc/trace.n +++ b/doc/trace.n @@ -54,9 +54,11 @@ execute them. When the trace triggers, depending on the operations being traced, a number of arguments are appended to \fIcommandPrefix\fR so that the actual command is as follows: +.PP .CS \fIcommandPrefix oldName newName op\fR .CE +.PP \fIOldName\fR and \fInewName\fR give the traced command's current (old) name, and the name to which it is being renamed (the empty string if this is a .QW delete @@ -121,9 +123,11 @@ number of arguments are appended to \fIcommandPrefix\fR so that the actual command is as follows: .PP For \fBenter\fR and \fBenterstep\fR operations: +.PP .CS \fIcommandPrefix command-string op\fR .CE +.PP \fICommand-string\fR gives the complete current command being executed (the traced command for a \fBenter\fR operation, an arbitrary command for a \fBenterstep\fR operation), including @@ -137,9 +141,11 @@ course when the command is subsequently executed, an error will occur. .PP For \fBleave\fR and \fBleavestep\fR operations: +.PP .CS \fIcommand command-string code result op\fR .CE +.PP \fICommand-string\fR gives the complete current command being executed (the traced command for a \fBenter\fR operation, an arbitrary command for a \fBenterstep\fR operation), including @@ -217,9 +223,11 @@ interpreter in which to execute them. .PP When the trace triggers, three arguments are appended to \fIcommandPrefix\fR so that the actual command is as follows: +.PP .CS \fIcommandPrefix name1 name2 op\fR .CE +.PP \fIName1\fR and \fIname2\fR give the name(s) for the variable being accessed: if the variable is a scalar then \fIname1\fR gives the variable's name and \fIname2\fR is an empty string; @@ -368,9 +376,11 @@ future version of Tcl. They use an older syntax in which \fBarray\fR, list, but simply a string concatenation of the operations, such as \fBrwua\fR. .SH EXAMPLES +.PP Print a message whenever either of the global variables \fBfoo\fR and \fBbar\fR are updated, even if they have a different local name at the time (which can be done with the \fBupvar\fR command): +.PP .CS proc tracer {varname args} { upvar #0 $varname var @@ -382,6 +392,7 @@ proc tracer {varname args} { .PP Ensure that the global variable \fBfoobar\fR always contains the product of the global variables \fBfoo\fR and \fBbar\fR: +.PP .CS proc doMult args { global foo bar foobar @@ -393,6 +404,7 @@ proc doMult args { .PP Print a trace of what commands are executed during the processing of a Tcl procedure: +.PP .CS proc x {} { y } proc y {} { z } @@ -409,3 +421,6 @@ x set(n), unset(n) .SH KEYWORDS read, command, rename, variable, write, trace, unset +.\" Local Variables: +.\" mode: nroff +.\" End: |