Shell Programming and Scripting

1|XXX
2|YYY
3|ZZZ

1|XXX
2|FFF
5|DDD
6|TTT

new => 
5|DDD
6|TTT

updated=>
2|FFF

deleted=>
3|ZZZ

$ cat 1.txt
1|XXX
2|YYY
3|ZZZ
$ cat 2.txt
1|XXX
2|FFF
5|DDD
6|TTT

awk -F'|' 'FNR==NR {buff[$1]=$0;next} 
                  {
                     if(buff[$1]=="")  { new[$1]=$0; next;}
                     if(buff[$1]==$0) { delete buff[$1]; next;}
                     if(buff[$1]!=$0) { chng[$1]=$0; delete buff[$1];}
                  }
                  END{

                     print "new==>"
                     for (var in new) print new[var];

                     print "\n\nupdated==>"
                     for (var in chng) print chng[var];

                     print "\n\ndeleted==>"
                     for (var in buff) if(buff[var]!="") print buff[var];
                  }' 1.txt 2.txt

new==>
5|DDD
6|TTT


updated==>
2|FFF


deleted==>
3|ZZZ