Node only shows part of the text

I need help,i need node only show some text ,No matter how long the node text is, only display fixed node size and fixed text length, thank

What OS are you using? (Windows, Linux, Apple?)
Are you open do doing some preprocessing or post-processing programming?

I can’t find easy way to truncate text to fit inside a node. I hoped the fixedsize attribute would truncate, but it doesn’t.
Converting the labels to images and including those images does not truncate - but it will shrink the image/text to fit. Might this solve your problem?
Or, if you can live with a fixed-width (monospaced) font like Courier (Courier (typeface) - Wikipedia), you could pre-calculate the total width of the node label and truncate the string before invoking Graphviz. Python or gvpr (https://www.graphviz.org/pdf/gvpr.1.pdf) could perform this fix. So could other languages.
If variable-width font(s) are needed, determining a correct substring starts be a real slog.