Batch conversion of cer to pem certificates with openssl and bash

While this example can be applied pretty generically - it came in useful when I was tasked with converting several dozen certificates:

#!/bin/bash
for i in *.cer;
  do
  echo Converting: $i...
  outfile=`echo $i | sed s/.cer/.pem/`
  openssl x509 -inform der -in $i -out $outfile
done