Just ask ChatGPT:

Hi,

I have text values that are set by an external software (it does find&replace for placeholders) and the values have spaces at the right (to fill the maximum field length I suppose).

I am new in postscript and trying to find a working example of trimming right spaces before calling the /code128 barcode generator. No success so far.

Is there an option in postcriptbarcode generators to do the trim? Or any well known postscript template that makes the same?

Thanks!

ChatGPT output:

In PostScript, there isn't a built-in right-trim function, but you can create one fairly easily. The postscriptbarcode library doesn't have a built-in trim option, so you'll need to handle this before passing the data to the barcode generator.

Here's PostScript code that uses a function to trim right spaces:

%PS

% ... BWIPP resources ...

/rtrim {
    dup length 1 sub
    { dup 2 index exch get 32 ne { 1 add exit } if 1 sub dup 0 lt { exit } if } loop
    0 exch getinterval
} bind def

0 0 moveto
(BARCODE123   ) rtrim
()
/code39 /uk.co.terryburton.bwipp findresource exec

showpage

[ The usual waffle ensues... ]
...