UNIX for Dummies Questions & Answers

while read line
do
grep -v $line file2.txt
done<file1.txt

grep -v

name1 num1 num2 num3
name2 num5 num6 num7
name3 num8 num9 num1
name4 num1 num2 num3
name5 num4 num5 num5

name1 str1 str2 str3
name2 str5 str6 str7
name3 str8 str9 str1

name4
name5

awk ' FILENAME=="file2.txt" {arr[$1]++}
        FILENAME=="file1.txt" {if ($1 in arr) {next} else {print $0}  }' file2.txt file1.txt

cat file1.txt file2.txt | awk '{print $1}' | sort | uniq -u

name4
name5