CODEWITHSUNDEEP
bashdatescriptingformat
Chris Allison
Chris Allison

Reputation: 15

How do I convert mm/dd/yy to yymmdd format in bash script?

I have a date field from a file with 50 dates in mm/dd/yy format. How can I convert it to yymmdd? I have seen questions similar, but going the opposite direction. I cant seem to apply it the way I need it.

Dates are saved in file as 01/20/72 and I need to convert them to 720120

Currently I have $bDate +%y%m%d as the command, but it is wrong. Thanks in advance!!

Upvotes: 0

Views: 1017

Answers (2)

Marc Bredt
Marc Bredt

Reputation: 955

you can use sed and its internal regexp storing vars like echo "01/20/72" | sed -r 's#(..)/(..)/(..)#\3\1\2#g'

Upvotes: 0

glenn jackman
glenn jackman

Reputation: 247042

string manipulation: bash regular expressions suffice here:

date="04/13/06"
d='[[:digit:]]'
if [[ $date =~ ($d$d)/($d$d)/($d$d) ]]; then 
   newdate=${BASH_REMATCH[3]}${BASH_REMATCH[1]}${BASH_REMATCH[2]}
fi
echo $newdate

060413

If you're repeatedly doing this, make it a function:

mdy2ymd() {
    local d='[[:digit:]]' newdate
    if [[ $1 =~ ($d$d)/($d$d)/($d$d) ]]; then 
       newdate=${BASH_REMATCH[3]}${BASH_REMATCH[1]}${BASH_REMATCH[2]}
    fi
    echo $newdate
}

Upvotes: 1

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