Hi my friend,
You can also just open any editer and type
awk 'length >= 10' $*
Then save it to a file.
Then chmod +x filename and run it as ./filename inputfile
Or, if you have many input files as you said, you may need a shell script with awk command in it. Suppose you use bash, you can do something like
for file in $@
awk 'length >= 10' $file
You can also put all your other commands in this file and then run it like above. Try to google shell script for more help.