Assuming you have no whitespace and no characters that are special characters of regular expressions contained in your strings in "file1".txt, the following awk-based approach should work:

awk 'NR==FNR{patterns[FNR]=$1} FNR<NR{if ($0 ~ patterns[FNR]) print "true"; else print "false"}' file1.txt file2.txt

For your example, this will yield

true
true
true
true
true
false

Assuming you have no whitespace contained in your strings in file1.txt, the following awk-based approach should work:

awk 'NR==FNR{patterns[FNR]=$1} FNR<NR{if (index($0,patterns[FNR])>0) print "true"; else print "false"}' file1.txt file2.txt

For your example, this will yield

true
true
true
true
true
false

Some explanation: We use awk to read in both files, but process them in a different way.

• While processing file1.txt, indicated by FNR, the "per-file line counter", being equal to NR, the global line counter, we simply register all (trimmed) strings ($1, which is the first whitespace-delimited field of the line) in an awk-internal array, with the line number as index (note that these start with 1).

• While processing file2.txt (FNR is now smaller than NR), we use the index function to look for the string patterns[FNR] in the entire input line ($0). If so, index() will return a start position larger than 0, and we print true, otherwise we print false.