It looks like you're not escaping single quotes in the find pattern, so the command output gets malformed. Also, you're reading in the whole file before replac

It looks like you're not escaping single quotes in the find pattern, so the command output gets malformed. Also, you're reading in the whole file before replacing, even though most uses of sed will probably be per line. Including an option for line-by-line (maybe as default) would be much better for large files.