Timestamp & date

Shell Programming and Scripting
1

Hi,

I have list of files as below, with prefix named as date & time. Anyone how to transform each file as below to yyyy-mm-dd hh:mm:ss

Regards,

2

chop out the date string from the file name and use
date +%F -d "<string>"
this will convert the string date to the yyyy-mm-dd format

3

It didn't work as expected

date +%F-d"`ll -lrt | awk '{print $9}' | cut -c1-6`"
August-d
080822
080822
080822
080822
080822
080822

4

Nothing wrong with the date solution -- you just need to run date one file at a time. (Use a for/while loop around ls -l). Meanwhile, perl's very handy to get the job done:

ls -1 | perl -n -e 'chop; print localtime( (stat($_))[9] ) . "\n";

The perl command processes each line of input (with -n option) and for each line, $_ is the input line. "chop" removes the newline character at the end of the line. "stat" retrieves the inode data from the filename (in $_). "localtime" will spit out the date/time of the file using the local timezone. (Use "gmtime" if you want it to ignore timezone settings.)

5

ls -E *.inp | awk '{print $6,$7}' | cut -d"." -f1

above command will give u the date and time as you expected..

6

U can try:

ls -l|while read file
do
   file2="$(echo ${file}|sed -e "s/\(..\)\(..\)\(..\)_\(..\)\(..\)\(..\)/20\1-\2-\3 \4:\5\:\6/")"
   mv "${file}" "${file2}"
done
7

Klashxx,

can u explain the above sed logic.

8

Every group of parenthesis \(..\) marks a group of characters in the filenames (because the first '_' character in the filename "anchors" the regular expression). In each group are two characters, which because of how you named your files, will be a number representing a portion of the date. After the second / (the substitution side), the back-quoted numbers (ie, \1 \2 \3, etc) refer "back" to the 1st, 2nd, 3rd group, respectively.

Put more succinctly, on the LHS of the 2nd /, the 2nd group of parenthesis matches exactly two characters and is represented on the RHS as \2. After sed does its work, your filenames will look like:

2008-08-22 05:00:01_FILE.TXT

9

what he said ! :slight_smile: