NAME<\/a> ______________________________________________________________________________<\/p>\n package \u2212 Facilities for package loading and version control<\/p>\n package forget<\/b> ?package package …<\/i>? This command keeps a simple database of the packages available for use by the current interpreter and how to load them into the interpreter. It supports multiple versions of each package and arranges for the correct version of a package to be loaded based on what is needed by the application. This command also detects and reports version clashes. Typically, only the package require<\/b> and package provide<\/b> commands are invoked in normal Tcl scripts; the other commands are used primarily by system scripts that maintain the package database.<\/p>\n The behavior of the package<\/b> command is determined by its first argument. The following forms are permitted: Removes all information about each specified package from this interpreter, including information provided by both package ifneeded<\/b> and package provide<\/b>.<\/p>\n package ifneeded<\/b> package version<\/i> ?script<\/i>?<\/p>\n This command typically appears only in system configuration scripts to set up the package database. It indicates that a particular version of a particular package is available if needed, and that the package can be added to the interpreter by executing script<\/i>. The script is saved in a database for use by subsequent package require<\/b> commands; typically, script<\/i> sets up auto-loading for the commands in the package (or calls load<\/b> and\/or source<\/b> directly), then invokes package provide<\/b> to indicate that the package is present. There may be information in the database for several different versions of a single package. If the database already contains information for package<\/i> and version<\/i>, the new script<\/i> replaces the existing one. If the script<\/i> argument is omitted, the current script for version version<\/i> of package package<\/i> is returned, or an empty string if no package ifneeded<\/b> command has been invoked for this package<\/i> and version<\/i>.<\/p>\n package names<\/b><\/p>\n Returns a list of the names of all packages in the interpreter for which a version has been provided (via package provide<\/b>) or for which a package ifneeded<\/b> script is available. The order of elements in the list is arbitrary.<\/p>\n package present<\/b> ?\u2212exact<\/b>? package<\/i> ?requirement…<\/i>?<\/p>\n This command is equivalent to package require<\/b> except that it does not try and load the package if it is not already loaded.<\/p>\n package provide<\/b> package<\/i> ?version<\/i>?<\/p>\n This command is invoked to indicate that version version<\/i> of package package<\/i> is now present in the interpreter. It is typically invoked once as part of an ifneeded<\/b> script, and again by the package itself when it is finally loaded. An error occurs if a different version of package<\/i> has been provided by a previous package provide<\/b> command. If the version<\/i> argument is omitted, then the command returns the version number that is currently provided, or an empty string if no package provide<\/b> command has been invoked for package<\/i> in this interpreter.<\/p>\n package require<\/b> package<\/i> ?requirement…<\/i>?<\/p>\n This command is typically invoked by Tcl code that wishes to use a particular version of a particular package. The arguments indicate which package is wanted, and the command ensures that a suitable version of the package is loaded into the interpreter. If the command succeeds, it returns the version number that is loaded; otherwise it generates an error.<\/p>\n A suitable version of the package is any version which satisfies at least one of the requirements, per the rules of package vsatisfies<\/b>. If multiple versions are suitable the implementation with the highest version is chosen. This last part is additionally influenced by the selection mode set with package prefer<\/b>.<\/p>\n In the \u201cstable\u201d selection mode the command will select the highest stable version satisfying the requirements, if any. If no stable version satisfies the requirements, the highest unstable version satisfying the requirements will be selected. In the \u201clatest\u201d selection mode the command will accept the highest version satisfying all the requirements, regardless of its stableness.<\/p>\n If a version of package<\/i> has already been provided (by invoking the package provide<\/b> command), then its version number must satisfy the requirement<\/i>s and the command returns immediately. Otherwise, the command searches the database of information provided by previous package ifneeded<\/b> commands to see if an acceptable version of the package is available. If so, the script for the highest acceptable version number is evaluated in the global namespace; it must do whatever is necessary to load the package, including calling package provide<\/b> for the package. If the package ifneeded<\/b> database does not contain an acceptable version of the package and a package unknown<\/b> command has been specified for the interpreter then that command is evaluated in the global namespace; when it completes, Tcl checks again to see if the package is now provided or if there is a package ifneeded<\/b> script for it. If all of these steps fail to provide an acceptable version of the package, then the command returns an error.<\/p>\n package require \u2212exact<\/b> package version<\/i><\/p>\n This form of the command is used when only the given version<\/i> of package<\/i> is acceptable to the caller. This command is equivalent to package require<\/b> package version<\/i>–version<\/i>.<\/p>\n package unknown<\/b> ?command<\/i>?<\/p>\n This command supplies a \u201clast resort\u201d command to invoke during package require<\/b> if no suitable version of a package can be found in the package ifneeded<\/b> database. If the command<\/i> argument is supplied, it contains the first part of a command; when the command is invoked during a package require<\/b> command, Tcl appends one or more additional arguments giving the desired package name and requirements. For example, if command<\/i> is foo bar<\/b> and later the command package require test 2.4<\/b> is invoked, then Tcl will execute the command foo bar test 2.4<\/b> to load the package. If no requirements are supplied to the package require<\/b> command, then only the name will be added to invoked command. If the package unknown<\/b> command is invoked without a command<\/i> argument, then the current package unknown<\/b> script is returned, or an empty string if there is none. If command<\/i> is specified as an empty string, then the current package unknown<\/b> script is removed, if there is one.<\/p>\n package vcompare<\/b> version1 version2<\/i><\/p>\n Compares the two version numbers given by version1<\/i> and version2<\/i>. Returns -1 if version1<\/i> is an earlier version than version2<\/i>, 0 if they are equal, and 1 if version1<\/i> is later than version2<\/i>.<\/p>\n package versions<\/b> package<\/i><\/p>\n Returns a list of all the version numbers of package<\/i> for which information has been provided by package ifneeded<\/b> commands.<\/p>\n package vsatisfies<\/b> version requirement…<\/i><\/p>\n Returns 1 if the version<\/i> satisfies at least one of the given requirements, and 0 otherwise. Each requirement<\/i> is allowed to have any of the forms:<\/p>\n
SYNOPSIS<\/a>
DESCRIPTION<\/a>
VERSION NUMBERS<\/a>
PACKAGE INDICES<\/a>
EXAMPLES<\/a>
SEE ALSO<\/a>
KEYWORDS<\/a> <\/p>\n
\nNAME <\/a> <\/h2>\n
SYNOPSIS <\/a> <\/h2>\n
package ifneeded<\/b> package version<\/i> ?script<\/i>?
package names
package present<\/b> package<\/i> ?requirement…<\/i>?
package present \u2212exact<\/b> package version<\/i>
package provide<\/b> package<\/i> ?version<\/i>?
package require<\/b> package<\/i> ?requirement…<\/i>?
package require \u2212exact<\/b> package version<\/i>
package unknown<\/b> ?command<\/i>?
package vcompare<\/b> version1 version2<\/i>
package versions<\/b> package<\/i>
package vsatisfies<\/b> version requirement…<\/i>
package prefer<\/b> ?latest<\/b>|stable<\/b>? ______________________________________________________________________________<\/p>\nDESCRIPTION <\/a> <\/h2>\n
package forget<\/b> ?package package …<\/i>?<\/p>\n