Commands tagged validation (5)

  • Validates and pretty-prints the content fetched from the URL. Show Sample Output

    curl -s "" | python -m json.tool | less -R
    keimlink · 2010-03-24 09:15:12 1
  • Place the regular expression you want to validate between the forward slashes in the eval block. Show Sample Output

    perl -we 'my $regex = eval {qr/.*/}; die "[email protected]" if [email protected];'
    tlacuache · 2009-10-13 21:50:47 1
  • 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

    if [ "$testnum" -eq "$testnum" 2>/dev/null ]; then echo It is numeric; fi
    jgc · 2009-10-09 14:57:27 4
  • 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

    if date -d 2006-10-10 >> /dev/null 2>&1; then echo 1; else echo 0; fi
    SteveGoossens · 2013-01-10 10:35:15 0
  • 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.

    echo 2006-10-10 | grep -c '^[0-9][0-9][0-9][0-9]-[0-9][0-9]-[0-9][0-9]$'
    rez0r · 2009-05-11 22:18:43 3

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Clone all repos from a user with lynx

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Watch the progress of 'dd'
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Comment out all lines in a file beginning with string

determine if tcp port is open
@putnamhill, no need if statement in that case. && is a AND and || is a OR

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