For each of the 150 files, assign an awk variable with the filename without the
.gtf extension. Use
; as a delimiter and where the first column matches "trascript", print 3 columns, the first being the sample id variable you assigned above, the second being the
transcript_id field and the third being the
TPM field. Append output across all files to a single combined output file.
You should be able to write your
awk command using the above logic.