Shell Programming and Scripting

egrep -v "Error 1|Error 2" logfile

#Create your working file, if this isn't a running logfile you can skip this step and just pipe the output from sort on A.log the next step.
cp A.log A.log.tmp

#Sort for unique values and grep on your common Error text
sort A.log.tmp | uniq | grep "Error" >> my_unique_errors.log

 awk 'BEGIN{i=1}(NR==1){a[i]=$0;b[i]=1;i++;next}
{for (j=1;j<i;j++){if($0==a[j]){b[j]+=1;next}};a[i]=$0;b[i]=1;i++}END{for (j=1;j<i;j++){print a[j]":"b[j]}}' a.log

Error 1:3
Error 2:2

cat file | grep  "Error"  | sort | uniq -c
      3 Error 1
      2 Error 2