'\" '\" Generated from file 'log\&.man' by tcllib/doctools with format 'nroff' '\" Copyright (c) 2001-2009 Andreas Kupries '\" .TH "log" 3tcl 1\&.4 tcllib "Logging facility" .\" 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 .de AP .ie !"\\$4"" .TP \\$4 .el \{\ . ie !"\\$2"" .TP \\n()Cu . el .TP 15 .\} .ta \\n()Au \\n()Bu .ie !"\\$3"" \{\ \&\\$1 \\fI\\$2\\fP (\\$3) .\".b .\} .el \{\ .br .ie !"\\$2"" \{\ \&\\$1 \\fI\\$2\\fP .\} .el \{\ \&\\fI\\$1\\fP .\} .\} .. .\" # define tabbing values for .AP .de AS .nr )A 10n .if !"\\$1"" .nr )A \\w'\\$1'u+3n .nr )B \\n()Au+15n .\" .if !"\\$2"" .nr )B \\w'\\$2'u+\\n()Au+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 .de BS .br .mk ^y .nr ^b 1u .if n .nf .if n .ti 0 .if n \l'\\n(.lu\(ul' .if n .fi .. .\" # BE - end boxed text (draw box now) .de BE .nf .ti 0 .mk ^t .ie n \l'\\n(^lu\(ul' .el \{\ .\" Draw four-sided box normally, but don't draw top of .\" box if the box started on an earlier page. .ie !\\n(^b-1 \{\ \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul' .\} .el \}\ \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul' .\} .\} .fi .br .nr ^b 0 .. .\" # 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 .de VE .ie n 'mc .el \{\ .ev 2 .nf .ti 0 .mk ^t \h'|\\n(^lu+3n'\L'|\\n(^Yu-1v\(bv'\v'\\n(^tu+1v-\\n(^Yu'\h'-|\\n(^lu+3n' .sp -1 .fi .ev .\} .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. .de ^B .ev 2 'ti 0 'nf .mk ^t .if \\n(^b \{\ .\" Draw three-sided box if this is the box's first page, .\" draw two sides but no top otherwise. .ie !\\n(^b-1 \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c .el \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c .\} .if \\n(^v \{\ .nr ^x \\n(^tu+1v-\\n(^Yu \kx\h'-\\nxu'\h'|\\n(^lu+3n'\ky\L'-\\n(^xu'\v'\\n(^xu'\h'|0u'\c .\} .bp 'fi .ev .if \\n(^b \{\ .mk ^y .nr ^b 2 .\} .if \\n(^v \{\ .mk ^Y .\} .. .\" # DS - begin display .de DS .RS .nf .sp .. .\" # DE - end display .de DE .fi .RE .sp .. .\" # 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 .de SE .fi .ft R .LP See the \\*(So manual entry for details on the standard options. .. .\" # OP - start of full description for a single option .de OP .LP .nf .ta 4c Command-Line Name: \\fB\\$1\\fR Database Name: \\fB\\$2\\fR Database Class: \\fB\\$3\\fR .fi .IP .. .\" # CS - begin code excerpt .de CS .RS .nf .ta .25i .5i .75i 1i .. .\" # CE - end code excerpt .de CE .fi .RE .. .\" # UL - underline word .de UL \\$1\l'|0\(ul'\\$2 .. .\" # 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 log \- Procedures to log messages of libraries and applications\&. .SH SYNOPSIS package require \fBTcl 8\fR .sp package require \fBlog ?1\&.4?\fR .sp \fB::log::levels\fR .sp \fB::log::lv2longform\fR \fIlevel\fR .sp \fB::log::lv2color\fR \fIlevel\fR .sp \fB::log::lv2priority\fR \fIlevel\fR .sp \fB::log::lv2cmd\fR \fIlevel\fR .sp \fB::log::lv2channel\fR \fIlevel\fR .sp \fB::log::lvCompare\fR \fIlevel1\fR \fIlevel2\fR .sp \fB::log::lvSuppress\fR \fIlevel\fR {\fIsuppress\fR 1} .sp \fB::log::lvSuppressLE\fR \fIlevel\fR {\fIsuppress\fR 1} .sp \fB::log::lvIsSuppressed\fR \fIlevel\fR .sp \fB::log::lvCmd\fR \fIlevel\fR \fIcmd\fR .sp \fB::log::lvCmdForall\fR \fIcmd\fR .sp \fB::log::lvChannel\fR \fIlevel\fR \fIchan\fR .sp \fB::log::lvChannelForall\fR \fIchan\fR .sp \fB::log::lvColor\fR \fIlevel\fR \fIcolor\fR .sp \fB::log::lvColorForall\fR \fIcolor\fR .sp \fB::log::log\fR \fIlevel\fR \fItext\fR .sp \fB::log::logarray\fR \fIlevel\fR \fIarrayvar\fR ?\fIpattern\fR? .sp \fB::log::loghex\fR \fIlevel\fR \fItext\fR \fIdata\fR .sp \fB::log::logsubst\fR \fIlevel\fR \fImsg\fR .sp \fB::log::logMsg\fR \fItext\fR .sp \fB::log::logError\fR \fItext\fR .sp \fB::log::Puts\fR \fIlevel\fR \fItext\fR .sp .BE .SH DESCRIPTION .PP The \fBlog\fR package provides commands that allow libraries and applications to selectively log information about their internal operation and state\&. .PP To use the package just execute .PP .CS package require log log::log notice "Some message" .CE .PP As can be seen above, each message given to the log facility is associated with a \fIlevel\fR determining the importance of the message\&. The user can then select which levels to log, what commands to use for the logging of each level and the channel to write the message to\&. In the following example the logging of all message with level \fBdebug\fR is deactivated\&. .PP .CS package require log log::lvSuppress debug log::log debug "Unseen message" ; # No output .CE .PP By default all messages associated with an error-level (\fBemergency\fR, \fBalert\fR, \fBcritical\fR, and \fBerror\fR) are written to \fBstderr\fR\&. Messages with any other level are written to \fBstdout\fR\&. In the following example the log module is reconfigured to write \fBdebug\fR messages to \fBstderr\fR too\&. .PP .CS package require log log::lvChannel debug stderr log::log debug "Written to stderr" .CE .PP Each message level is also associated with a command to use when logging a message with that level\&. The behaviour above for example relies on the fact that all message levels use by default the standard command \fB::log::Puts\fR to log any message\&. In the following example all messages of level \fBnotice\fR are given to the non-standard command \fBtoText\fR for logging\&. This disables the channel setting for such messages, assuming that \fBtoText\fR does not use it by itself\&. .PP .CS package require log log::lvCmd notice toText log::log notice "Handled by \\"toText\\"" .CE .PP Another database maintained by this facility is a map from message levels to colors\&. The information in this database has \fIno\fR influence on the behaviour of the module\&. It is merely provided as a convenience and in anticipation of the usage of this facility in \fBtk\fR-based application which may want to colorize message logs\&. .SH API .PP The following commands are available: .TP \fB::log::levels\fR Returns the names of all known levels, in alphabetical order\&. .TP \fB::log::lv2longform\fR \fIlevel\fR Converts any unique abbreviation of a level name to the full level name\&. .TP \fB::log::lv2color\fR \fIlevel\fR Converts any level name including unique abbreviations to the corresponding color\&. .TP \fB::log::lv2priority\fR \fIlevel\fR Converts any level name including unique abbreviations to the corresponding priority\&. .TP \fB::log::lv2cmd\fR \fIlevel\fR Converts any level name including unique abbreviations to the command prefix used to write messages with that level\&. .TP \fB::log::lv2channel\fR \fIlevel\fR Converts any level name including unique abbreviations to the channel used by \fB::log::Puts\fR to write messages with that level\&. .TP \fB::log::lvCompare\fR \fIlevel1\fR \fIlevel2\fR Compares two levels (including unique abbreviations) with respect to their priority\&. This command can be used by the -command option of lsort\&. The result is one of -1, 0 or 1 or an error\&. A result of -1 signals that level1 is of less priority than level2\&. 0 signals that both levels have the same priority\&. 1 signals that level1 has higher priority than level2\&. .TP \fB::log::lvSuppress\fR \fIlevel\fR {\fIsuppress\fR 1} (Un)suppresses the output of messages having the specified level\&. Unique abbreviations for the level are allowed here too\&. .TP \fB::log::lvSuppressLE\fR \fIlevel\fR {\fIsuppress\fR 1} (Un)suppresses the output of messages having the specified level or one of lesser priority\&. Unique abbreviations for the level are allowed here too\&. .TP \fB::log::lvIsSuppressed\fR \fIlevel\fR Asks the package whether the specified level is currently suppressed\&. Unique abbreviations of level names are allowed\&. .TP \fB::log::lvCmd\fR \fIlevel\fR \fIcmd\fR Defines for the specified level with which command to write the messages having this level\&. Unique abbreviations of level names are allowed\&. The command is actually a command prefix and this facility will append 2 arguments before calling it, the level of the message and the message itself, in this order\&. .TP \fB::log::lvCmdForall\fR \fIcmd\fR Defines for all known levels with which command to write the messages having this level\&. The command is actually a command prefix and this facility will append 2 arguments before calling it, the level of the message and the message itself, in this order\&. .TP \fB::log::lvChannel\fR \fIlevel\fR \fIchan\fR Defines for the specified level into which channel \fB::log::Puts\fR (the standard command) shall write the messages having this level\&. Unique abbreviations of level names are allowed\&. The command is actually a command prefix and this facility will append 2 arguments before calling it, the level of the message and the message itself, in this order\&. .TP \fB::log::lvChannelForall\fR \fIchan\fR Defines for all known levels with which which channel \fB::log::Puts\fR (the standard command) shall write the messages having this level\&. The command is actually a command prefix and this facility will append 2 arguments before calling it, the level of the message and the message itself, in this order\&. .TP \fB::log::lvColor\fR \fIlevel\fR \fIcolor\fR Defines for the specified level the color to return for it in a call to \fB::log::lv2color\fR\&. Unique abbreviations of level names are allowed\&. .TP \fB::log::lvColorForall\fR \fIcolor\fR Defines for all known levels the color to return for it in a call to \fB::log::lv2color\fR\&. Unique abbreviations of level names are allowed\&. .TP \fB::log::log\fR \fIlevel\fR \fItext\fR Log a message according to the specifications for commands, channels and suppression\&. In other words: The command will do nothing if the specified level is suppressed\&. If it is not suppressed the actual logging is delegated to the specified command\&. If there is no command specified for the level the message won't be logged\&. The standard command \fB::log::Puts\fR will write the message to the channel specified for the given level\&. If no channel is specified for the level the message won't be logged\&. Unique abbreviations of level names are allowed\&. Errors in the actual logging command are \fInot\fR caught, but propagated to the caller, as they may indicate misconfigurations of the log facility or errors in the callers code itself\&. .TP \fB::log::logarray\fR \fIlevel\fR \fIarrayvar\fR ?\fIpattern\fR? Like \fB::log::log\fR, but logs the contents of the specified array variable \fIarrayvar\fR, possibly restricted to entries matching the \fIpattern\fR\&. The pattern defaults to \fB*\fR (i\&.e\&. all entries) if none was specified\&. .TP \fB::log::loghex\fR \fIlevel\fR \fItext\fR \fIdata\fR Like \fB::log::log\fR, but assumes that \fIdata\fR contains binary data\&. It converts this into a mixed hex/ascii representation before writing them to the log\&. .TP \fB::log::logsubst\fR \fIlevel\fR \fImsg\fR Like \fB::log::log\fR, but \fImsg\fR may contain substitutions and variable references, which are evaluated in the caller scope first\&. The purpose of this command is to avoid overhead in the non-logging case, if the log message building is expensive\&. Any substitution errors raise an error in the command execution\&. The following example shows an xml text representation, which is only generated in debug mode: .CS log::logsubst debug {XML of node $node is '[$node toXml]'} .CE .TP \fB::log::logMsg\fR \fItext\fR Convenience wrapper around \fB::log::log\fR\&. Equivalent to \fB::log::log info text\fR\&. .TP \fB::log::logError\fR \fItext\fR Convenience wrapper around \fB::log::log\fR\&. Equivalent to \fB::log::log error text\fR\&. .TP \fB::log::Puts\fR \fIlevel\fR \fItext\fR The standard log command, it writes messages and their levels to user-specified channels\&. Assumes that the suppression checks were done by the caller\&. Expects full level names, abbreviations are \fInot allowed\fR\&. .PP .SH LEVELS The package currently defines the following log levels, the level of highest importance listed first\&. .IP \(bu emergency .IP \(bu alert .IP \(bu critical .IP \(bu error .IP \(bu warning .IP \(bu notice .IP \(bu info .IP \(bu debug .PP \fINote\fR that by default all messages with levels \fBwarning\fR down to \fBdebug\fR are suppressed\&. This is done intentionally, because (we believe that) in most situations debugging output is not wanted\&. Most people wish to have such output only when actually debugging an application\&. .SH "BUGS, IDEAS, FEEDBACK" This document, and the package it describes, will undoubtedly contain bugs and other problems\&. Please report such in the category \fIlog\fR of the \fITcllib Trackers\fR [http://core\&.tcl\&.tk/tcllib/reportlist]\&. Please also report any ideas for enhancements you may have for either package and/or documentation\&. .PP When proposing code changes, please provide \fIunified diffs\fR, i\&.e the output of \fBdiff -u\fR\&. .PP Note further that \fIattachments\fR are strongly preferred over inlined patches\&. Attachments can be made by going to the \fBEdit\fR form of the ticket immediately after its creation, and then using the left-most button in the secondary navigation bar\&. .SH KEYWORDS log, log level, message, message level .SH CATEGORY Programming tools .SH COPYRIGHT .nf Copyright (c) 2001-2009 Andreas Kupries .fi