Shell Programming and Scripting

 
for i in *.txt
do
awk -F, -v OFS=, '$2==2{$2=1;print $0}' $i > $i.out
done

for files in *csv
do
  awk '{print FILENAME;}' $files
done

 
for i in *.txt
do
awk -F, -v OFS=, '$2==2{$2=1;print $0}' $i > $i.out
mv $i.out $i
done

for i in *.txt
do
awk -F, -v OFS=, '$2==2{$2=1;print $0}' $i > $i.out
awk -F, -v OFS=, '$2==3{$2=1;print $0}' $i >> $i.out
mv $i.out $i
done

awk -F, -v OFS=, '{if($2~/^[23]$/){$2=1;print $0}}' $i >> $i.out