The Convert Hexadecimal Text to Unsigned Integer routine converts
    an ASCII text string representation of an unsigned hexadecimal
    value to an unsigned integer. The integer value can be of
    arbitrary length but is typically a byte, word, longword, or
    quadword. The default size of the result is a longword.

    Format

      OTS$CVT_TZ_L  fixed-or-dynamic-input-string

                    ,varying-output-value [,output-value-size]

                    [,flags-value]

1  –  Returns

    OpenVMS usage:cond_value
    type:         longword (unsigned)
    access:       write only
    mechanism:    by value

2  –  Arguments

 fixed-or-dynamic-input-string

    OpenVMS usage:char_string
    type:         character string
    access:       read only
    mechanism:    by descriptor, fixed-length or dynamic string

    Input string containing the string representation of an unsigned
    hexadecimal value that OTS$CVT_TZ_L converts to an unsigned
    integer. The fixed-or-dynamic-input-string argument is the
    address of a descriptor pointing to the input string. The valid
    input characters are blanks, the digits 0 through 7, and the
    letters A through F. Letters can be uppercase or lowercase. No
    sign is permitted.

 varying-output-value

    OpenVMS usage:varying_arg
    type:         unspecified
    access:       write only
    mechanism:    by reference

    Unsigned integer of specified size that OTS$CVT_TZ_L creates
    when it converts the ASCII text string. The varying-output-value
    argument is the address of the unsigned integer. The value of the
    output-value-size argument determines the size in bytes of the
    output value.

 output-value-size

    OpenVMS usage:longword_signed
    type:         longword (signed)
    access:       read only
    mechanism:    by value

    Arbitrary number of bytes to be occupied by the unsigned integer
    output value. The output-value-size argument contains a value
    that equals the size in bytes of the output value. If the value
    of output-value-size is zero or a negative number, OTS$CVT_TZ_L
    returns an input conversion error. If you omit the output-value-
    size argument, the default is 4 (longword).

 flags-value

    OpenVMS usage:mask_longword
    type:         longword (unsigned)
    access:       read only
    mechanism:    by value

    User-supplied flags that OTS$CVT_TZ_L uses to determine how
    to interpret blanks within the input string. The flags-value
    argument contains these user-supplied flags as described in the
    following table:

    Bit  Action if Set    Action if Clear

    0    Ignore all       Interpret blanks as zeros.
         blanks.

    If you omit the flags-value argument, OTS$CVT_TZ_L defaults the
    flag to clear.