'\" '\" Copyright (c) 1998 Mark Harrison. '\" '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" '\" SCCS: @(#) msgcat.n '\" '\" 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 1.1.1.1 2007/07/10 15:04:23 duncan Exp $ '\" '\" # 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 .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 \\fBoptions\\fR 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 .. .de UL \\$1\l'|0\(ul'\\$2 .. .TH "msgcat" n 1.3 msgcat "Tcl Bundled Packages" .BS '\" Note: do not modify the .SH NAME line immediately below! .SH NAME msgcat \- Tcl message catalog .SH SYNOPSIS \fBpackage require Tcl 8.2\fR .sp \fBpackage require msgcat 1.3.4\fR .sp \fB::msgcat::mc \fIsrc-string\fR ?\fIarg arg ...\fR? .sp \fB::msgcat::mcmax ?\fIsrc-string src-string ...\fR? .sp \fB::msgcat::mclocale \fR?\fInewLocale\fR? .sp \fB::msgcat::mcpreferences\fR .sp \fB::msgcat::mcload \fIdirname\fR .sp \fB::msgcat::mcset \fIlocale src-string \fR?\fItranslate-string\fR? .sp \fB::msgcat::mcmset \fIlocale src-trans-list\fR .sp \fB::msgcat::mcunknown \fIlocale src-string\fR .BE .SH DESCRIPTION .PP The \fBmsgcat\fR package provides a set of functions that can be used to manage multi-lingual user interfaces. Text strings are defined in a ``message catalog'' which is independent from the application, and which can be edited or localized without modifying the application source code. New languages or locales are provided by adding a new file to the message catalog. .PP Use of the message catalog is optional by any application or package, but is encouraged if the application or package wishes to be enabled for multi-lingual applications. .SH COMMANDS .TP \fB::msgcat::mc \fIsrc-string\fR ?\fIarg arg ...\fR? Returns a translation of \fIsrc-string\fR according to the user's current locale. If additional arguments past \fIsrc-string\fR are given, the \fBformat\fR command is used to substitute the additional arguments in the translation of \fIsrc-string\fR. .PP \fB::msgcat::mc\fR will search the messages defined in the current namespace for a translation of \fIsrc-string\fR; if none is found, it will search in the parent of the current namespace, and so on until it reaches the global namespace. If no translation string exists, \fB::msgcat::mcunknown\fR is called and the string returned from \fB::msgcat::mcunknown\fR is returned. .PP \fB::msgcat::mc\fR is the main function used to localize an application. Instead of using an English string directly, an application can pass the English string through \fB::msgcat::mc\fR and use the result. If an application is written for a single language in this fashion, then it is easy to add support for additional languages later simply by defining new message catalog entries. .TP \fB::msgcat::mcmax ?\fIsrc-string src-string ...\fR? Given several source strings, \fB::msgcat::mcmax\fR returns the length of the longest translated string. This is useful when designing localized GUIs, which may require that all buttons, for example, be a fixed width (which will be the width of the widest button). .TP \fB::msgcat::mclocale \fR?\fInewLocale\fR? This function sets the locale to \fInewLocale\fR. If \fInewLocale\fR is omitted, the current locale is returned, otherwise the current locale is set to \fInewLocale\fR. msgcat stores and compares the locale in a case-insensitive manner, and returns locales in lowercase. The initial locale is determined by the locale specified in the user's environment. See \fBLOCALE SPECIFICATION\fR below for a description of the locale string format. .TP \fB::msgcat::mcpreferences\fR Returns an ordered list of the locales preferred by the user, based on the user's language specification. The list is ordered from most specific to least preference. The list is derived from the current locale set in msgcat by \fB::msgcat::mclocale\fR, and cannot be set independently. For example, if the current locale is en_US_funky, then \fB::msgcat::mcpreferences\fR returns \fB{en_US_funky en_US en}\fR. .TP \fB::msgcat::mcload \fIdirname\fR Searches the specified directory for files that match the language specifications returned by \fB::msgcat::mcpreferences\fR (note that these are all lowercase), extended by the file extension ``.msg''. Each matching file is read in order, assuming a UTF-8 encoding. The file contents are then evaluated as a Tcl script. This means that Unicode characters may be present in the message file either directly in their UTF-8 encoded form, or by use of the backslash-u quoting recognized by Tcl evaluation. The number of message files which matched the specification and were loaded is returned. .TP \fB::msgcat::mcset \fIlocale src-string \fR?\fItranslate-string\fR? Sets the translation for \fIsrc-string\fR to \fItranslate-string\fR in the specified \fIlocale\fR and the current namespace. If \fItranslate-string\fR is not specified, \fIsrc-string\fR is used for both. The function returns \fItranslate-string\fR. .TP \fB::msgcat::mcmset \fIlocale src-trans-list\fR Sets the translation for multiple source strings in \fIsrc-trans-list\fR in the specified \fIlocale\fR and the current namespace. \fIsrc-trans-list\fR must have an even number of elements and is in the form {\fIsrc-string translate-string\fR ?\fIsrc-string translate-string ...\fR?} \fB::msgcat::mcmset\fR can be significantly faster than multiple invocations of \fB::msgcat::mcset\fR. The function returns the number of translations set. .TP \fB::msgcat::mcunknown \fIlocale src-string\fR This routine is called by \fB::msgcat::mc\fR in the case when a translation for \fIsrc-string\fR is not defined in the current locale. The default action is to return \fIsrc-string\fR. This procedure can be redefined by the application, for example to log error messages for each unknown string. The \fB::msgcat::mcunknown\fR procedure is invoked at the same stack context as the call to \fB::msgcat::mc\fR. The return value of \fB::msgcat::mcunknown\fR is used as the return value for the call to \fB::msgcat::mc\fR. .SH "LOCALE SPECIFICATION" .PP The locale is specified to \fBmsgcat\fR by a locale string passed to \fB::msgcat::mclocale\fR. The locale string consists of a language code, an optional country code, and an optional system-specific code, each separated by ``_''. The country and language codes are specified in standards ISO-639 and ISO-3166. For example, the locale ``en'' specifies English and ``en_US'' specifies U.S. English. .PP When the msgcat package is first loaded, the locale is initialized according to the user's environment. The variables \fBenv(LC_ALL)\fR, \fBenv(LC_MESSAGES)\fR, and \fBenv(LANG)\fR are examined in order. The first of them to have a non-empty value is used to determine the initial locale. The value is parsed according to the XPG4 pattern .CS language[_country][.codeset][@modifier] .CE to extract its parts. The initial locale is then set by calling \fB::msgcat::mclocale\fR with the argument .CS language[_country][_modifier] .CE On Windows, if none of those environment variables is set, msgcat will attempt to extract locale information from the registry. If all these attempts to discover an initial locale from the user's environment fail, msgcat defaults to an initial locale of ``C''. .PP When a locale is specified by the user, a ``best match'' search is performed during string translation. For example, if a user specifies en_GB_Funky, the locales ``en_GB_Funky'', ``en_GB'', and ``en'' are searched in order until a matching translation string is found. If no translation string is available, then \fB::msgcat::mcunknown\fR is called. .SH "NAMESPACES AND MESSAGE CATALOGS" .PP Strings stored in the message catalog are stored relative to the namespace from which they were added. This allows multiple packages to use the same strings without fear of collisions with other packages. It also allows the source string to be shorter and less prone to typographical error. .PP For example, executing the code .CS \fB::msgcat::mcset\fR en hello "hello from ::" namespace eval foo { \fB::msgcat::mcset\fR en hello "hello from ::foo" } puts [\fB::msgcat::mc\fR hello] namespace eval foo {puts [\fB::msgcat::mc\fR hello]} .CE will print .CS hello from :: hello from ::foo .CE .PP When searching for a translation of a message, the message catalog will search first the current namespace, then the parent of the current namespace, and so on until the global namespace is reached. This allows child namespaces to "inherit" messages from their parent namespace. .PP For example, executing (in the ``en'' locale) the code .CS \fB::msgcat::mcset\fR en m1 ":: message1" \fB::msgcat::mcset\fR en m2 ":: message2" \fB::msgcat::mcset\fR en m3 ":: message3" namespace eval ::foo { \fB::msgcat::mcset\fR en m2 "::foo message2" \fB::msgcat::mcset\fR en m3 "::foo message3" } namespace eval ::foo::bar { \fB::msgcat::mcset\fR en m3 "::foo::bar message3" } namespace import \fB::msgcat::mc\fR puts "[\fBmc\fR m1]; [\fBmc\fR m2]; [\fBmc\fR m3]" namespace eval ::foo {puts "[\fBmc\fR m1]; [\fBmc\fR m2]; [\fBmc\fR m3]"} namespace eval ::foo::bar {puts "[\fBmc\fR m1]; [\fBmc\fR m2]; [\fBmc\fR m3]"} .CE will print .CS :: message1; :: message2; :: message3 :: message1; ::foo message2; ::foo message3 :: message1; ::foo message2; ::foo::bar message3 .CE .SH "LOCATION AND FORMAT OF MESSAGE FILES" .PP Message files can be located in any directory, subject to the following conditions: .IP [1] All message files for a package are in the same directory. .IP [2] The message file name is a msgcat locale specifier (all lowercase) followed by ``.msg''. For example: .CS es.msg -- spanish en_gb.msg -- United Kingdom English .CE .IP [3] The file contains a series of calls to \fBmcset\fR and \fBmcmset\fR, setting the necessary translation strings for the language, likely enclosed in a \fBnamespace eval\fR so that all source strings are tied to the namespace of the package. For example, a short \fBes.msg\fR might contain: .CS namespace eval ::mypackage { \fB::msgcat::mcset\fR es "Free Beer!" "Cerveza Gracias!" } .CE .SH "RECOMMENDED MESSAGE SETUP FOR PACKAGES" .PP If a package is installed into a subdirectory of the \fBtcl_pkgPath\fR and loaded via \fBpackage require\fR, the following procedure is recommended. .IP [1] During package installation, create a subdirectory \fBmsgs\fR under your package directory. .IP [2] Copy your *.msg files into that directory. .IP [3] Add the following command to your package initialization script: .CS # load language files, stored in msgs subdirectory \fB::msgcat::mcload\fR [file join [file dirname [info script]] msgs] .CE .SH "POSITIONAL CODES FOR FORMAT AND SCAN COMMANDS" .PP It is possible that a message string used as an argument to \fBformat\fR might have positionally dependent parameters that might need to be repositioned. For example, it might be syntactically desirable to rearrange the sentence structure while translating. .CS format "We produced %d units in location %s" $num $city format "In location %s we produced %d units" $city $num .CE .PP This can be handled by using the positional parameters: .CS format "We produced %1\\$d units in location %2\\$s" $num $city format "In location %2\\$s we produced %1\\$d units" $num $city .CE .PP Similarly, positional parameters can be used with \fBscan\fR to extract values from internationalized strings. .SH CREDITS .PP The message catalog code was developed by Mark Harrison. .SH "SEE ALSO" format(n), scan(n), namespace(n), package(n) .SH KEYWORDS internationalization, i18n, localization, l10n, message, text, translation