How to determine SSL cert expiration date from a PEM encoded certificate?

Question

If I have the actual file and a Bash shell in Mac or Linux, how can I query the cert file for when it will expire? Not a web site, but actually the certificate file itself,

Answer 1

Here's my bash command line to list multiple certificates in order of their expiration, most recently expiring first.

for pem in /etc/ssl/certs/*.pem; do 
   printf '%s: %s\n' \
      "$(date --date="$(openssl x509 -enddate -noout -in "$pem"|cut -d= -f 2)" --iso-8601)" \
      "$pem"
done | sort

Sample output:

2015-12-16: /etc/ssl/certs/Staat_der_Nederlanden_Root_CA.pem
2016-03-22: /etc/ssl/certs/CA_Disig.pem
2016-08-14: /etc/ssl/certs/EBG_Elektronik_Sertifika_Hizmet_S.pem