NAME

       Tcl_PkgRequire,  Tcl_PkgRequireEx,  Tcl_PkgRequireProc, Tcl_PkgPresent, Tcl_PkgPresentEx, Tcl_PkgProvide,
       Tcl_PkgProvideEx - package version control

SYNOPSIS

       #include <tcl.h>

       const char *
       Tcl_PkgRequire(interp, name, version, exact)

       const char *
       Tcl_PkgRequireEx(interp, name, version, exact, clientDataPtr)

       int
       Tcl_PkgRequireProc(interp, name, objc, objv, clientDataPtr)

       const char *
       Tcl_PkgPresent(interp, name, version, exact)

       const char *
       Tcl_PkgPresentEx(interp, name, version, exact, clientDataPtr)

       int
       Tcl_PkgProvide(interp, name, version)

       int
       Tcl_PkgProvideEx(interp, name, version, clientData)

ARGUMENTS

       Tcl_Interp *interp (in)                Interpreter where package is needed or available.

       const char *name (in)                  Name of package.

       const char *version (in)               A version  string  consisting  of  one  or  more  decimal  numbers
                                              separated by dots.

       int exact (in)                         Non-zero  means  that  only  the  particular  version specified by
                                              version is  acceptable.   Zero  means  that  newer  versions  than
                                              version  are  also  acceptable as long as they have the same major
                                              version number as version.

       ClientData clientData (in)             Arbitrary value to be associated with the package.

       ClientData *clientDataPtr (out)        Pointer to place to store the value associated with  the  matching
                                              package.  It  is  only  changed if the pointer is not NULL and the
                                              function completed successfully.

       int objc (in)                          Number of requirements.

       Tcl_Obj* objv[] (in)                   Array of requirements.
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DESCRIPTION

       These procedures provide C-level interfaces to Tcl's package and version management facilities.

       Tcl_PkgRequire is equivalent to the package require command, Tcl_PkgPresent is equivalent to the  package
       present command, and Tcl_PkgProvide is equivalent to the package provide command.

       See the documentation for the Tcl commands for details on what these procedures do.

       If Tcl_PkgPresent or Tcl_PkgRequire complete successfully they return a pointer to the version string for
       the version of the package that is provided in the interpreter (which may be different than version);  if
       an error occurs they return NULL and leave an error message in the interpreter's result.

       Tcl_PkgProvide  returns  TCL_OK if it completes successfully; if an error occurs it returns TCL_ERROR and
       leaves an error message in the interpreter's result.

       Tcl_PkgProvideEx, Tcl_PkgPresentEx and Tcl_PkgRequireEx allow the setting and retrieving  of  the  client
       data associated with the package. In all other respects they are equivalent to the matching functions.

       Tcl_PkgRequireProc  is  the  form  of package require handling multiple requirements. The other forms are
       present for backward compatibility and translate their invocations to this form.

KEYWORDS

       package, present, provide, require, version