Shell Programming and Scripting

A.txt
B.ttx
C.txt
E.txt

A.txt
B.txt
C.txt
D.txt

awk 'NR==FNR{a[$1]=$1;next} !($1 in a){print $1 > "File2_to_File1_differance"}' file1_details_check1211231 file_details_check12111232
awk 'NR==FNR{a[$1]=$1;next} !($1 in a){print $1 > "File1_to_File2_differance"}' file_details_check12111232 file1_details_check1211231

awk 'NR==FNR{a[$1]=$1;next} !($1 in a){print $1 > "File2_to_File1_differance"}' file1_details_check1211231 file_details_check12111232
 
 cat File2_to_File1_differance
D.txt
 
awk 'NR==FNR{a[$1]=$1;next} !($1 in a){print $1 > "File1_to_File2_differance"}' file_details_check12111232 file1_details_check1211231
 
cat File1_to_File2_differance
E.txt

awk '
FNR == NR {
	a[$1]
	next
}
{	if($1 in a)
		delete a[$1]
	else	print $1 > "file3.txt"
}
END {	for(i in a)
		print i > "File4.txt"
}' File1 File2

B.txt
D.txt

B.ttx
E.txt