some data cleaning shell

datacleaning.sh

# Change extension for txt files to csv files
$ for f in *.txt
do
	[ -f "$f" ] && mv "$f" "${f%txt}csv"
done

# Remove first line every csv files
$ for f in *.csv
do
	[ -f "$f" ] && awk '{if (NR==1 || NR==2) next};1' "$f" >> "clean_$f"
done

# Add a column with name of file for each csv file
$ for f in *.csv
do
	[ -f "$f" ] && awk -F" " 'BEGIN { OFS = " " } ; {if (NR==1) next} ; { $6="'$f'" OFS $6; print}' "$f" >> "new_$f"
done