debug (3)
NAME
debug - debug narrative - coreSYNOPSIS
package require Tcl 8.5package require debug ?1.0.6?
debug.tag message ?level?
debug 2array
debug define tag
debug header text
debug level tag ?level? ?fd?
debug names
debug off tag
debug on tag
debug parray arrayvarname
debug pdict dict
debug hexl data ?prefix?
debug nl
debug tab
debug prefix tag ?text?
debug setting (tag level) ... ?fd?
debug suffix tag ?text?
debug trailer text
DESCRIPTION
Debugging areas of interest are represented by 'tags' which have independently settable levels of interest (an integer, higher is more detailed).API
- debug.tag message ?level?
-
For each known tag the package creates a command with this signature
the user can then use to provide the debug narrative of the tag.
The narrative message is provided as a Tcl script whose value is
substed in the caller's scope if and only if the current level of
interest for the tag matches or exceeds the call's level
of detail. This is useful, as one can place arbitrarily complex
narrative in code without unnecessarily evaluating it.
See methods level and setting for querying and manipulating the current level of detail for tags.
The actually printed text consists of not only the message, but also global and tag-specific prefix and suffix, should they exist, with each line in the message having the specified headers and trailers.
All these parts are substableTcl scripts, which are substituted once per message before assembly.
- debug 2array
-
This method returns a dictionary mapping the names of all debug tags
currently known to the package to their state and log level. The
latter are encoded in a single numeric value, where a negative number
indicates an inactive tag at the level given by the absolute value, and
a positive number is an active tag at that level.
See also method settings below.
- debug define tag
-
This method registers the named tag with the package. If the
tag was not known before it is placed in an inactive state. The state
of an already known tag is left untouched.
The result of the method is the empty string.
- debug header text
-
This method defines a global substable Tcl script which provides
a text printed before each line of output.
Note how this is tag-independent.
Further note that the header substitution happens only once per actual printed message, i.e. all lines of the same message will have the same actual heading text.
The result of the method is the specified text.
- debug level tag ?level? ?fd?
-
This method sets the detail-level for the tag, and the
channel fd to write the tags narration into.
The level is an integer value >= 0 defaulting to 1.
The channel defaults to stderr.
The result of the method is the new detail-level for the tag.
- debug names
- This method returns a list containing the names of all debug tags currently known to the package.
- debug off tag
-
This method registers the named tag with the package and sets it
inactive.
The result of the method is the empty string.
- debug on tag
-
This method registers the named tag with the package, as active.
The result of the method is the empty string.
- debug parray arrayvarname
-
This is a convenience method formatting the named array like the
builtin command parray, except it returns the resulting string
instead of writing it directly to stdout.
This makes it suitable for use in debug messages.
- debug pdict dict
-
This is a convenience method formatting the dictionary similarly to
how the builtin command parray does for array, and returns the
resulting string.
This makes it suitable for use in debug messages.
- debug hexl data ?prefix?
-
This is a convenience method formatting arbitrary data into a hex-dump
and returns the resulting string.
This makes it suitable for use in debug messages.
Each line of the dump is prefixed with prefix. This prefix defaults to the empty string.
- debug nl
- This is a convenience method to insert a linefeed character (ASCII 0x0a) into a debug message.
- debug tab
- This is a convenience method to insert a TAB character (ASCII 0x09) into a debug message.
- debug prefix tag ?text?
-
This method is similar to the method header above, in that it
defines substable Tcl script which provides more text for debug
messages.
In contrast to header the generated text is added to the user's message before it is split into lines, making it a per-message extension.
Furthermore the script is tag-dependent.
In exception to that, a script for tag :: is applied to all messages.
If both global and tag-dependent prefix exist, both are applied, with the global prefix coming before the tag-dependent prefix.
Note that the prefix substitution happens only once per actual printed message.
The result of the method is the empty string.
If the tag was not known at the time of the call it is registered, and set inactive.
- debug setting (tag level) ... ?fd?
-
This method is a multi-tag variant of method level above,
with the functionality of methods on, and off also
folded in.
Each named tag is set to the detail-level following it, with a negative level deactivating the tag, and a positive level activating it.
If the last argument is not followed by a level it is not treated as tag name, but as the channel all the named tags should print their messages to.
The result of the method is the empty string.
- debug suffix tag ?text?
-
This method is similar to the method trailer below, in that
it defines substable Tcl script which provides more text for
debug messages.
In contrast to trailer the generated text is added to the user's message before it is split into lines, making it a per-message extension.
Furthermore the script is tag-dependent.
In exception to that, a script for tag :: is applied to all messages.
If both global and tag-dependent suffix exist, both are applied, with the global suffix coming after the tag-dependent suffix.
Note that the suffix substitution happens only once per actual printed message.
The result of the method is the empty string.
If the tag was not known at the time of the call it is registered, and set inactive.
- debug trailer text
-
This method defines a global substable Tcl script which provides
a text printed after each line of output (before the EOL however).
Note how this is tag-independent.
Further note that the trailer substitution happens only once per actual printed message, i.e. all lines of the same message will have the same actual trailing text.
The result of the method is the specified text.
BUGS, IDEAS, FEEDBACK
This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category debug of the Tcllib Trackers [core.tcl.tk/tcllib/reportlist] Please also report any ideas for enhancements you may have for either package and/or documentation.KEYWORDS
debug, log, narrative, traceCATEGORY
debugging, tracing, and loggingCOPYRIGHT
Copyright (c) 200?, Colin McCormack, Wub Server Utilities Copyright (c) 2012-2014, Andreas Kupries <andreas_kupries@users.sourceforge.net>