CODEWITHSUNDEEP
bashdatetime
Jagte
Jagte

Reputation: 533

Ensuring correct time format in bash

I have a script which asks the user the following question:

read -p "Input time duration of simulation in HH:MM:SS format" -e Time

Now how do I ensure the user entered the correct form for $Time before the variable $Time is actually used?

Upvotes: 1

Views: 1683

Answers (2)

doubleDown
doubleDown

Reputation: 8398

I assume you need to check hour < 24, minutes < 60, seconds < 60? 

read -p "Input time duration of simulation in HH:MM:SS format " -e Time

while :; do
  if [[ $Time =~ ^([0-9]{2}):([0-9]{2}):([0-9]{2})$ ]]; then
    if (( BASH_REMATCH[3] < 60 ))\
       && (( BASH_REMATCH[2] < 60 ))\
       && (( BASH_REMATCH[1] < 24 )); then
       break
    fi
  fi
  read -p "Wrong format. Please use the HH:MM:SS format " -e Time
done

# Do something with $Time

Upvotes: 2

Gilles Qu&#233;not
Gilles Qu&#233;not

Reputation: 185025

You can test it like that :

if [[ $Time =~ ^[0-9][0-9]:[0-9][0-9]:[0-9][0-9]$ ]]; then
    echo "format is ok"
else
    echo >&2 "format is wrong"
fi

Upvotes: 0

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