/********************************* REXX ***********************************/
/* Bruce A. Woodworth             STRIPOP              September 22, 2002 */
/*                                                                        */
/* This REXX EXEC removes a string from a string.                         */
/*                                                                        */
/* This EXEC accepts 2 strings.  The first is the string which will be    */
/* returned.  The second is the string which will be stripped from the    */
/* first string.                                                          */
/*                                                                        */
/* Syntax:                                                                */
/*         STRIPOP( option_string, keyword )                              */
/*                                                                        */
/* Ex:                                                                    */
/*         STRIPOP( THE_OPTIONS, "/CNT" )                                 */
/*                                                                        */
/*   In this example, the string, THE_OPTIONS, will be scanned for the    */
/*   word /CNT.  If it is found, then the string, /CNT, will be stripped  */
/*   from THE_OPTIONS and THE_OPTIONS will then be returned.              */
/*                                                                        */
/**************************************************************************/
    parse upper arg the_options, the_keyword

    if the_options = "?" ³ the_keyword = "" ³ the_options = ""
    then
        do
            option_val = 0
            init = setinit()
            logon_id = userid()
            'disphelp' setrexx(init) ³³ '(stripop)'
        end
    else
        call check_option

    return(option_val)

check_option:

    if the_options = the_keyword
    then
        option_val = ""
    else
        call reformat_option_string

    return

reformat_option_string:

    keyword_loc = index(the_options, the_keyword)

    keyword_size = truelen(the_keyword)
    option_size = length(the_options)

    if keyword_loc = 0
    then
        option_val = the_options
    else
        do
            if keyword_loc = 1
            then
                call grab_second_half
            else
                call grab_around_string
        end

    return

grab_second_half:

    string_start = keyword_size + 1
    check_next_byte = substr(the_options,string_start,1)
    do while check_next_byte = " "

        string_start = string_start + 1
        check_next_byte = substr(the_options,string_start,1)

    end

    throw_away = string_start - 1
    string_size = option_size - throw_away
    option_val = substr(the_options,string_start,string_size)

    return

grab_around_string:

    first_size = keyword_loc - 1
    first_piece = substr(the_options,1,first_size)
    second_size = option_size - keyword_size - first_size
    second_loc = keyword_loc + keyword_size
    second_piece = substr(the_options,second_loc,second_size)

    if second_size > 0
    then
        temp_string = first_piece ³³ second_piece
    else
        temp_string = first_piece

    call remove_trailing_blanks

    return

remove_trailing_blanks:

    option_val = ""
    new_size = length(temp_string)
    last_char = substr(temp_string,new_size,1)
    do while last_char = " " & new_size > 1

        new_size = new_size - 1
        last_char = substr(temp_string,new_size,1)

    end

    if new_size = 1 & last_char = " "
    then
        option_val = ""
    else
        option_val = substr(temp_string,1,new_size)

    return