Validates and pretty-prints the content fetched from the URL. Show Sample Output
Place the regular expression you want to validate between the forward slashes in the eval block. Show Sample Output
Using the standard numeric comparison but suppressing the STDERR output acts as the simplest way to check a value is numeric. See sample output for some examples. Show Sample Output
On CentOS at least, date returns a boolean for the common date string formats, including YYYY-MM-DD. In the sample output, you can see various invalid dates returning 0 whereas a simple regex check would return 1 for the invalid dates. -d, --date=STRING display time described by STRING, not `now' The version of date on OS X does not appear to have this same option. Show Sample Output
Quick and easy way of validating a date format of yyyy-mm-dd and returning a boolean, the regex can easily be upgraded to handle "in betweens" for mm dd or to validate other types of strings, ex. ip address. Boolean output could easily be piped into a condition for a more complete one-liner.
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