SipX generates config files as a single long line of PXXX=YY&PXXX=YY&... .
Comparing two of these files to highlight only changed P-values can be done
using git:

git diff -U0 --word-diff --word-diff-regex='P[^&]+&' --no-index --text -- old-tftproot/cfg000xxxxxxxxx new-tftproot/cfg000xxxxxxxxx


-U0: output no surrounding context lines (usually git diff would output 3

--word-diff: diff word by word within a line instead of line by line

--word-diff-regex='P[^&]+&': defines a "word" to be anything of the form P...&
(i.e. a P, any number of chars that aren't ampersand, followed by ampserand).

--no-index: allows comparing files that are not in a git repository

--text: force treating the files as plain text (sipX writes some binary
garbage at the beginning that would normally get the file treated as binary)

--: end of switches