What are you trying to achieve ? - there may be some other way of doing it that is more appropriate.
for example I have a cgats file with raw rgb data
case #1, I have spectral measurements produced by something else in cgats format
case #2, I have spectral measurements produced by argyll chartread (.ti3 has also XYZ and/or LAB, even I do not need to have them, no option to exclude... not a bid deal, but for consistency again it is good to be able to say that I only need spectral data)
case #1, using txt2ti3 to combine the files gives the output that I like : raw rgb from the actual shot + spectral data from the target measurements, leaving whatever software further down the chain to use the spectral data as it can/need
case #2, using txt2ti3 to combine the files gives me raw rgb + but no spectral data included, which kind of makes using chartread more difficult to use in this situation
inconsistent at least ! what I 'd love to have is to use argyll chartread to measure a target and then use txt2ti3 to combine raw rgb data with just spectral data from chartread output... w/o using text editors, etc... yes, I understand the origin how txt2ti3 was intended to be used, but
PS: and if the target measuments were not in 10nm (but for example like -H mode in 3.33x increments), why it is necessary to strip intermediate measurements from the source file and output only SPEC_380, SPEC_390, etc ?