[SOLVED] How to change date format with Sed command?

Issue

I am trying to change the date format from YYYY-MM-DD to DD/MM/YYYY in all lines of a file using the sed command.

For example:

2021-04-01 00:15,69,0,38,1,1,0,0,0,32

should be:

01-04-2021 00:15,69,0,38,1,1,0,0,0,32

I have tried the following using regular expressions:

sed -E 's,[0-9]{4}-[0-9]{2}-[0-9]{2},\3-\2-\1,g'

unfortunately this does not work and gives me an error (not defined in the RE).

it would be really great if someone could help me to solve this.

Solution

You forgot capturing groups with ( ):

$ sed -E 's,^([0-9]{4})-([0-9]{2})-([0-9]{2}),\3-\2-\1,g' <<< '2021-04-01 00:15,69,0,38,1,1,0,0,0,32'
01-04-2021 00:15,69,0,38,1,1,0,0,0,32

Answered By - Gilles Quénot

Answer Checked By - Dawn Plyler (WPSolving Volunteer)