Uses dot and space as field separators, this is so we can pickup filename without extension (eg bb from bb.txt).
NR==FNR{f=$0;sub(".*/","",f);F[f]=$0;next} Store pathnames in file_2 into array F[] with index as basename of file.
$1 in F{$0=F[$1]} if field 1 (bit before any fullstop) from file_1 is available in the F[] array then assign line as the fullpathname we stored from file_1 earlier, otherwise leave it as it is.
!/NAME/ If the new line from previous command does not contain NAME then print it out.[/icode]