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Diffstat (limited to 'doc/library.n')
| -rw-r--r-- | doc/library.n | 92 |
1 files changed, 56 insertions, 36 deletions
diff --git a/doc/library.n b/doc/library.n index 8845ef8..775b7d9 100644 --- a/doc/library.n +++ b/doc/library.n @@ -5,19 +5,17 @@ '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" -'\" RCS: @(#) $Id: library.n,v 1.17 2004/06/16 21:20:42 dgp Exp $ -.so man.macros .TH library n "8.0" Tcl "Tcl Built-In Commands" +.so man.macros .BS .SH NAME -auto_execok, auto_import, auto_load, auto_mkindex, auto_mkindex_old, auto_qualify, auto_reset, tcl_findLibrary, parray, tcl_endOfWord, tcl_startOfNextWord, tcl_startOfPreviousWord, tcl_wordBreakAfter, tcl_wordBreakBefore \- standard library of Tcl procedures +auto_execok, auto_import, auto_load, auto_mkindex, auto_qualify, auto_reset, tcl_findLibrary, parray, tcl_endOfWord, tcl_startOfNextWord, tcl_startOfPreviousWord, tcl_wordBreakAfter, tcl_wordBreakBefore \- standard library of Tcl procedures .SH SYNOPSIS .nf \fBauto_execok \fIcmd\fR \fBauto_import \fIpattern\fR \fBauto_load \fIcmd\fR \fBauto_mkindex \fIdir pattern pattern ...\fR -\fBauto_mkindex_old \fIdir pattern pattern ...\fR \fBauto_qualify \fIcommand namespace\fR \fBauto_reset\fR \fBtcl_findLibrary \fIbasename version patch initScript enVarName varName\fR @@ -28,7 +26,6 @@ auto_execok, auto_import, auto_load, auto_mkindex, auto_mkindex_old, auto_qualif \fBtcl_wordBreakAfter \fIstr start\fR \fBtcl_wordBreakBefore \fIstr start\fR .BE - .SH INTRODUCTION .PP Tcl includes a library of Tcl procedures for commonly-needed functions. @@ -41,20 +38,21 @@ its own library of support procedures as well; the location of this library is normally given by the value of the \fB$\fIapp\fB_library\fR global variable, where \fIapp\fR is the name of the application. For example, the location of the Tk library is kept in the variable -\fB$tk_library\fR. +\fBtk_library\fR. .PP To access the procedures in the Tcl library, an application should source the file \fBinit.tcl\fR in the library, for example with the Tcl command +.PP .CS \fBsource [file join [info library] init.tcl]\fR .CE +.PP If the library procedure \fBTcl_Init\fR is invoked from an application's \fBTcl_AppInit\fR procedure, this happens automatically. The code in \fBinit.tcl\fR will define the \fBunknown\fR procedure and arrange for the other procedures to be loaded on-demand using the auto-load mechanism defined below. - .SH "COMMAND PROCEDURES" .PP The following procedures are provided in the Tcl library: @@ -67,7 +65,7 @@ named by \fIcmd\fR. If not, it returns an empty string. This command examines the directories in the current search path (given by the PATH environment variable) in its search for an executable file named \fIcmd\fR. On Windows platforms, the search is expanded with the same -directories and file extensions as used by \fBexec\fR. \fBAuto_exec\fR +directories and file extensions as used by \fBexec\fR. \fBAuto_execok\fR remembers information about previous searches in an array named \fBauto_execs\fR; this avoids the path search in future calls for the same \fIcmd\fR. The command \fBauto_reset\fR may be used to force @@ -86,8 +84,8 @@ matching rules of \fBnamespace import\fR. This command attempts to load the definition for a Tcl command named \fIcmd\fR. To do this, it searches an \fIauto-load path\fR, which is a list of one or more directories. The auto-load path is given by the -global variable \fB$auto_path\fR if it exists. If there is no -\fB$auto_path\fR variable, then the TCLLIBPATH environment variable is +global variable \fBauto_path\fR if it exists. If there is no +\fBauto_path\fR variable, then the TCLLIBPATH environment variable is used, if it exists. Otherwise the auto-load path consists of just the Tcl library directory. Within each directory in the auto-load path there must be a file \fBtclIndex\fR that describes one or more @@ -97,7 +95,7 @@ with the \fBauto_mkindex\fR command. If \fIcmd\fR is found in an index file, then the appropriate script is evaluated to create the command. The \fBauto_load\fR command returns 1 if \fIcmd\fR was successfully created. The command returns 0 if there was no index -entry for \fIcmd\fR or if the script didn't actually define \fIcmd\fR +entry for \fIcmd\fR or if the script did not actually define \fIcmd\fR (e.g. because index information is out of date). If an error occurs while processing the script, then that error is returned. \fBAuto_load\fR only reads the index information once and saves it in @@ -108,6 +106,7 @@ cached index information may be deleted with the command reload the index database from disk. .TP \fBauto_mkindex \fIdir pattern pattern ...\fR +. Generates an index suitable for use by \fBauto_load\fR. The command searches \fIdir\fR for all files whose names match any of the \fIpattern\fR arguments (matching is done with the \fBglob\fR @@ -116,10 +115,11 @@ in all the matching files, and stores the index information in a file named \fBtclIndex\fR in \fIdir\fR. If no pattern is given a pattern of \fB*.tcl\fR will be assumed. For example, the command .RS +.PP .CS \fBauto_mkindex foo *.tcl\fR .CE -.LP +.PP will read all the \fB.tcl\fR files in subdirectory \fBfoo\fR and generate a new index file \fBfoo/tclIndex\fR. .PP @@ -130,24 +130,30 @@ auto_mkindex_parser package to register other commands that can contribute to the auto_load index. You will have to read through auto.tcl to see how this works. .PP -\fBAuto_mkindex_old\fR parses the Tcl scripts in a relatively -unsophisticated way: if any line contains the word \fBproc\fR +\fBAuto_mkindex_old\fR +(which has the same syntax as \fBauto_mkindex\fR) +parses the Tcl scripts in a relatively +unsophisticated way: if any line contains the word +.QW \fBproc\fR as its first characters then it is assumed to be a procedure definition and the next word of the line is taken as the procedure's name. -Procedure definitions that don't appear in this way (e.g. they +Procedure definitions that do not appear in this way (e.g.\ they have spaces before the \fBproc\fR) will not be indexed. If your -script contains "dangerous" code, such as global initialization +script contains +.QW dangerous +code, such as global initialization code or procedure names with special characters like \fB$\fR, -\fB*\fR, \fB[\fR or \fB]\fR, you are safer using auto_mkindex_old. +\fB*\fR, \fB[\fR or \fB]\fR, you are safer using \fBauto_mkindex_old\fR. .RE .TP \fBauto_reset\fR +. Destroys all the information cached by \fBauto_execok\fR and \fBauto_load\fR. This information will be re-read from disk the next time it is needed. \fBAuto_reset\fR also deletes any procedures listed in the auto-load index, so that fresh copies of them will be -loaded the next time that they're used. +loaded the next time that they are used. .TP \fBauto_qualify \fIcommand namespace\fR Computes a list of fully qualified names for \fIcommand\fR. This list @@ -173,25 +179,27 @@ This is a standard search procedure for use by extensions during their initialization. They call this procedure to look for their script library in several standard directories. The last component of the name of the library directory is -normally \fIbasenameversion\fP -(e.g., tk8.0), but it might be "library" when in the build hierarchies. +normally \fIbasenameversion\fR +(e.g., tk8.0), but it might be +.QW library +when in the build hierarchies. The \fIinitScript\fR file will be sourced into the interpreter once it is found. The directory in which this file is found is -stored into the global variable \fIvarName\fP. +stored into the global variable \fIvarName\fR. If this variable is already defined (e.g., by C code during application initialization) then no searching is done. Otherwise the search looks in these directories: -the directory named by the environment variable \fIenVarName\fP; +the directory named by the environment variable \fIenVarName\fR; relative to the Tcl library directory; relative to the executable file in the standard installation -bin or bin/\fIarch\fP directory; +bin or bin/\fIarch\fR directory; relative to the executable file in the current build tree; relative to the executable file in a parallel build tree. .TP \fBparray \fIarrayName\fR Prints on standard output the names and values of all the elements in the array \fIarrayName\fR. -\fBArrayName\fR must be an array accessible to the caller of \fBparray\fR. +\fIArrayName\fR must be an array accessible to the caller of \fBparray\fR. It may be either local or global. .TP \fBtcl_endOfWord \fIstr start\fR @@ -230,11 +238,12 @@ Returns the index of the first word boundary before the starting index boundaries before the starting point in the given string. The index returned refers to the second character of the pair that comprises a boundary. - .SH "VARIABLES" .PP The following global variables are defined or used by the procedures in -the Tcl library: +the Tcl library. They fall into two broad classes, handling unknown +commands and packages, and determining what are words. +.SS "AUTOLOADING AND PACKAGE MANAGEMENT VARIABLES" .TP \fBauto_execs\fR Used by \fBauto_execok\fR to record information about whether @@ -253,26 +262,36 @@ If set to any value, then \fBunknown\fR will not attempt to auto-load any commands. .TP \fBauto_path\fR +. If set, then it must contain a valid Tcl list giving directories to -search during auto-load operations. +search during auto-load operations (including for package index +files when using the default \fBpackage unknown\fR handler). This variable is initialized during startup to contain, in order: -the directories listed in the TCLLIBPATH environment variable, -the directory named by the $tcl_library variable, -the parent directory of $tcl_library, -the directories listed in the $tcl_pkgPath variable. +the directories listed in the \fBTCLLIBPATH\fR environment variable, +the directory named by the \fBtcl_library\fR global variable, +the parent directory of \fBtcl_library\fR, +the directories listed in the \fBtcl_pkgPath\fR variable. +Additional locations to look for files and package indices should +normally be added to this variable using \fBlappend\fR. .TP \fBenv(TCL_LIBRARY)\fR If set, then it specifies the location of the directory containing library scripts (the value of this variable will be assigned to the \fBtcl_library\fR variable and therefore returned by -the command \fBinfo library\fR). If this variable isn't set then +the command \fBinfo library\fR). If this variable is not set then a default value is used. .TP \fBenv(TCLLIBPATH)\fR If set, then it must contain a valid Tcl list giving directories to search during auto-load operations. Directories must be specified in -Tcl format, using "/" as the path separator, regardless of platform. +Tcl format, using +.QW / +as the path separator, regardless of platform. This variable is only used when initializing the \fBauto_path\fR variable. +.SS "WORD BOUNDARY DETERMINATION VARIABLES" +These variables are only used in the \fBtcl_endOfWord\fR, +\fBtcl_startOfNextWord\fR, \fBtcl_startOfPreviousWord\fR, +\fBtcl_wordBreakAfter\fR, and \fBtcl_wordBreakBefore\fR commands. .TP \fBtcl_nonwordchars\fR This variable contains a regular expression that is used by routines @@ -290,9 +309,10 @@ word or not. If the pattern matches a character, the character is considered to be a word character. On Windows platforms, words are comprised of any character that is not a space, tab, or newline. Under Unix, words are comprised of numbers, letters or underscores. - .SH "SEE ALSO" -info(n), re_syntax(n) - +env(n), info(n), re_syntax(n) .SH KEYWORDS auto-exec, auto-load, library, unknown, word, whitespace +'\"Local Variables: +'\"mode: nroff +'\"End: |