UNIX for Dummies Questions & Answers

I have a text file with a very long list of dates, one date per line. Each date is in the same format yyyymmdd. I need the dates to be in mmddyyyy format.

This is part of a larger tcsh shell script.

I am just learning unix and came up with:

for each line in file
for each character in line
build a file using cut
use paste to rebuild the line in rearranged format mmddyyyy
rebuild total file from each linefile.

while this should work (i haven't built it yet), it's clearly a hack approach.

Can anyone point me in a better direction?

echo 'yyyymmdd' | sed 's/^\(....\)\(..\)\(..\)$/\2\3\1/'

Hello again vgersh99,

So, how would i implement this in a script. My input file is called 4 and it looks like this

20161115
20190815
20200215
20200515
20200815
20210215

I want the output file say 4d to look like

11152016
08152019
02152020
...

sed 's/^\(....\)\(..\)\(..\)$/\2\3\1/' 4 > 4d

U ROCK!


...thanks again