Regular Expressions 101

AWS EventBridge Scheduling Expressions

1

Regular Expression
Java 8

"
^(?:rate[(](?:(?:1[ ]+(hour|minute|day))|(?:[0-9]+[ ]+(hours|minutes|days)))[)])|(?:cron[(](?:(?:(?:[0-5]?[0-9])|[*])(?:(?:[-](?:(?:[0-5]?[0-9])|[*]))|(?:[/][0-9]+))?(?:[,](?:(?:[0-5]?[0-9])|[*])(?:(?:[-](?:(?:[0-5]?[0-9])|[*]))|(?:[/][0-9]+))?)*)[ ]+(?:(?:(?:[0-2]?[0-9])|[*])(?:(?:[-](?:(?:[0-2]?[0-9])|[*]))|(?:[/][0-9]+))?(?:[,](?:(?:[0-2]?[0-9])|[*])(?:(?:[-](?:(?:[0-2]?[0-9])|[*]))|(?:[/][0-9]+))?)*)[ ]+(?:(?:[?][ ]+(?:(?:(?:[1]?[0-9])|(?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC)|[*])(?:(?:[-](?:(?:[1]?[0-9])|(?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC)|[*])(?:[/][0-9]+)?)|(?:[/][0-9]+))?(?:[,](?:(?:[1]?[0-9])|(?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC)|[*])(?:(?:[-](?:(?:[1]?[0-9])|(?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC)|[*])(?:[/][0-9]+)?)|(?:[/][0-9]+))?)*)[ ]+(?:(?:(?:[1-7]|(?:SUN|MON|TUE|WED|THU|FRI|SAT))[#][0-5])|(?:(?:(?:(?:[1-7]|(?:SUN|MON|TUE|WED|THU|FRI|SAT))L?)|[L*])(?:(?:[-](?:(?:(?:[1-7]|(?:SUN|MON|TUE|WED|THU|FRI|SAT))L?)|[L*]))|(?:[/][0-9]+))?(?:[,](?:(?:(?:[1-7]|(?:SUN|MON|TUE|WED|THU|FRI|SAT))L?)|[L*])(?:(?:[-](?:(?:(?:[1-7]|(?:SUN|MON|TUE|WED|THU|FRI|SAT))L?)|[L*]))|(?:[/][0-9]+))?)*)))|(?:(?:(?:(?:(?:[1-3]?[0-9])W?)|LW|[L*])(?:(?:[-](?:(?:(?:[1-3]?[0-9])W?)|LW|[L*]))|(?:[/][0-9]+))?(?:[,](?:(?:(?:[1-3]?[0-9])W?)|LW|[L*])(?:(?:[-](?:(?:(?:[1-3]?[0-9])W?)|LW|[L*]))|(?:[/][0-9]+))?)*)[ ]+(?:(?:(?:[1]?[0-9])|(?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC)|[*])(?:(?:[-](?:(?:[1]?[0-9])|(?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC)|[*])(?:[/][0-9]+)?)|(?:[/][0-9]+))?(?:[,](?:(?:[1]?[0-9])|(?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC)|[*])(?:(?:[-](?:(?:[1]?[0-9])|(?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC)|[*])(?:[/][0-9]+)?)|(?:[/][0-9]+))?)*)[ ]+[?]))[ ]+(?:(?:(?:[12][0-9]{3})|[*])(?:(?:[-](?:(?:[12][0-9]{3})|[*]))|(?:[/][0-9]+))?(?:[,](?:(?:[12][0-9]{3})|[*])(?:(?:[-](?:(?:[12][0-9]{3})|[*]))|(?:[/][0-9]+))?)*)[)])$
"
g

Description

This validates AWS EventBridge scheduling expressions using the rate() and cron() formats.

It may not catch all invalid expressions, but it should properly validate all valid expressions, as demonstrated in the unit tests. Please let me know if I missed any valid expressions.

Originally attempted this using named capture groups and named back-references to reduce duplication. Unfortunately, named capture support is tricky, so they were all converted to duplicated non-capturing groups instead.

Submitted by Evan S Kaufman <evan@evanskaufman.com> - 3 months ago (Last modified 2 months ago)