load(5)

                                  load(1tcl)
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   load -- load machine code and initialize new commands 

Synopsis

   load fileName
   load fileName packageName
   load fileName packageName interp

Description

   This command loads binary code from a file into the application's
   address space and calls an initialization procedure in the package to
   incorporate it into an interpreter. fileName is the name of the file
   containing the code; its exact form varies from system to system but
   on most systems it is a shared library, such as a .so file under
   Solaris or a DLL under Windows. packageName is the name of the
   package, and is used to compute the name of an initialization
   procedure. interp is the path name of the interpreter into which to
   load the package (see interp(1tcl) for details). If interp is omitted,
   it defaults to the interpreter in which the load command was invoked.

   Once the file has been loaded into the application's address space,
   one of two initialization procedures will be invoked in the new code.
   Typically the initialization procedure will add new commands to a Tcl
   interpreter. The name of the initialization procedure is determined by
   packageName and whether or not the target interpreter is a safe one.
   For normal interpreters the name of the initialization procedure will
   have the form pkg_Init, where pkg is the same as packageName except
   that the first letter is converted to upper case and all other letters
   are converted to lower case. For example, if packageName is foo or
   FOo, the initialization procedure's name will be Foo_Init.

   If the target interpreter is a safe interpreter, then the name of the
   initialization procedure will be pkg_SafeInit instead of pkg_Init.

   The initialization procedure must match the following prototype:
   typedef int Tcl_PackageInitProc(Tcl_Interp *interp);

   The interp argument identifies the interpreter in which the package is
   to be loaded. The initialization procedure must return TCL_OK or
   TCL_ERROR to indicate whether or not it completed successfully; in the
   event of an error it should set interp->result to point to an error
   message. The result of the load command will be the result returned by
   the initialization procedure.

   The actual loading of a file will only be done once for each fileName
   in an application. If a given fileName is loaded into multiple
   interpreters, then the first load will load the code and call the
   initialization procedure; subsequent load will call the initialization
   procedure without loading the code again. It is not possible to unload
   or reload a package.

   The load command also supports packages that are statically linked
   with the application, if those packages have been registered by
   calling the Tcl_StaticPackage procedure. If fileName is an empty
   string, then packageName must be specified.

   If packageName is omitted or specified as an empty string, Tcl tries
   to guess the name of the package. This may be done differently on
   different platforms. The default guess, which is used on most UNIX
   platforms, is to take the last element of fileName, strip off the
   first three characters if they are lib, and use any following
   alphabetic and underline characters as the module name.

   For example, the command load libxyz4.2.so uses the module name xyz
   and the command load bin/last.so {} uses the module name last.

   If fileName is an empty string, then packageName must be specified.
   The load command first searches for a statically loaded package (one
   that has been registered by calling the Tcl_StaticPackage procedure)
   by that name; if one is found, it is used. Otherwise, the load command
   searches for a dynamically loaded package by that name, and uses it if
   it is found. If several different files have been loaded with
   different versions of the package, Tcl picks the file that was loaded
   first.

Limitations

   If the same file is loaded by different fileNames, it will be loaded
   into the process's address space multiple times. The behavior of this
   varies from system to system (some systems may detect the redundant
   loads, others may not).
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   25 April 2004
   © 2004 The SCO Group, Inc. All rights reserved.
   UnixWare 7 Release 7.1.4 - 25 April 2004