Shell Programming and Scripting

wc -l file1.txt
58112
wc -l file2.txt
55260
 
head -5 file1.txt
101214200123
101214700300
101250030067
101214100500
109912312312
 
head -5 file2.txt
101250030067
101214200123
101214700333
109912312312
101214700300

 $ awk 'NR==FNR{A[$1]++;next}{if(! A[$1]){print }else{A[$1]=0}}END{for(i in A){if(A[i]){print i}}}' file1 file2

101214700333
101214100500

$ awk 'FNR==NR{A[$1]++;next}{if(!($1 in  A))print;else delete A[$1]}END{for (i in A)print i}' file1 file2

101214700333
101214100500

comm -23 file1.txt file2.txt

$ cat file

101250030067
101214200123
101214700333
109912312312
101214700300
101214700333
101214700333
109912312312

$ awk '{A[$1]++}END{for(i in A) print i,A[i]}' file

101214700333 3 # It has 3 occurrence in the file so A[i]=3
101214200123 1 # It has 1 occurrence in the file so A[i]=1
109912312312 2 # It has 2 occurrence in the file so A[i]=2
101214700300 1
101250030067 1

awk 'FNR==NR {A[$1]; next}
{if ($1 in  A) delete A[$1]; else print $1} END {for (i in A) print i}' file1 file2