# 
      return [isMonoInstalled] 
    } 
  } 
 
  # 
  # NOTE: This procedure verifies that the specified value is indeed a valid 
  #       package name.  The packageName argument is the value to verify. 
  #       This procedure may raise script errors. 
  # 
  # <internal> 
  proc verifyPackageName { packageName } { 
    if {[string length $packageName] > 0 && \ 
        ![regexp -nocase -- {^[A-Z][0-9A-Z\.]*$} $packageName]} then { 
      error "package name must be alphanumeric and start with a letter" 
    } 
  } 
 
  # 
  # NOTE: This procedure verifies that the specified value is indeed a valid 
  #       patch level.  The patchLevel argument is the value to verify.  This 
  #       procedure may raise script errors. 
  # 
  # <internal> 
  proc verifyPackagePatchLevel { patchLevel } { 
    if {[string length $patchLevel] > 0 && \ 
        ![regexp -nocase -- {^\d+\.\d+(?:\.\d+){0,2}$} $patchLevel]} then { 
      error "patch level must use dotted decimal notation" 
    } 
  } 
 
  # 
  # NOTE: This procedure verifies the combination of language and version 
  #       specified by the caller.  The language argument must be one of the 
  #       literal strings "eagle", "tcl", or "client".  The version argument 
  #       must be one of the literal strings "8.4", "8.5", or "8.6" when the 

        error "unsupported client version" 
      } 
 
      set isClient true 
    } else { 
      error "unsupported language" 
      error "unsupported package language" 
    } 
  } 
 
  # 
  # NOTE: This procedure returns the name of the current platform.  There are 

        # 
        # NOTE: This platform name is supported verbatim, do nothing. 
        # 
      } 
      default { 
        error "unsupported platform" 
        error "unsupported package platform" 
      } 
    } 
  } 
 
  # 

  # <public> 
  proc checkForHigherVersion { language version platform packageName usePgp } { 
    variable clientDirectory 
    variable persistentRootDirectory 
 
    verifyPackageName $packageName 
    verifyLanguageAndVersion $language $version isClient 
    verifyPlatform $platform platform 
 
    set temporaryDirectory [getUniqueTempDirectory pkgd_ver_] 
 

    variable branchName 
    variable platformsUri 
    variable platformsUrn 
 
    # 
    # NOTE: Verify that the package language and version are correct. 
    # NOTE: Verify that the package name, language, and version are correct. 
    # 
    verifyPackageName $packageName 
    verifyLanguageAndVersion $language $version isClient 
 
    set temporaryDirectory [getUniqueTempDirectory pkgd_plat_] 
 
    set localFileName [file join $temporaryDirectory manifest.txt] 

        [getDictionaryValue $options -useAutoPath]] 
 
    set allowUpdate [string is true -strict \ 
        [getDictionaryValue $options -allowUpdate]] 
 
    # 
    # NOTE: Verify that the package language, version, and platform are 
    #       correct. 
    # 
    verifyLanguageAndVersion $language $version isClient 
    verifyPlatform $platform platform 
 
    set temporaryDirectory [getUniqueTempDirectory pkgd_lib_]