How do i extract the date from multiple files with dates in it?

Question

Lets say i have multiple filesnames e.g. R014-20171109-1159.log.20171109_1159. I want to create a shell script which creates for every given date a folder and moves the files matching the date to it. Is this possible?

For the example a folder "20171109" should be created and has the file "R014-20171109-1159.log.20171109_1159" on it.

Thanks

Sure it's possible. What did you try, and where are you stuck? — Sebastian Schmied, Nov 30 '17 at 12:51
I don't know how to extract the date with an regular expression. — Biggie Smalls, Nov 30 '17 at 12:54
Provide some code samples that you tried or maybe some tutorials you tried to follow. — UditS, Nov 30 '17 at 13:20

Jithin Scaria · Answer 1 · 2017-11-30T13:33:18.893

Below commands can be put in script to achieve this,

Assign a variable with current date as below ( use --date='n day ago' option if need to have an older date).

if need to get it from File name itself, get files in a loop then use cut command to get the date string,

dirVar=$(date +%Y%m%d) --> for current day,

dirVar=$(date +%Y%m%d --date='1 day ago') --> for yesterday,

dirVar=$(echo $fileName | cut -c6-13)   or
dirVar=$(echo $fileName | cut -d- -f2) --> to get from $fileName

Create directory with the variable value as below, (-p : create directory if doesn't exist.)

mkdir -p ${dirVar}

Move files to directory to the directory with below line,

mv *log.${dirVar}* ${dirVar}/

score 0 · Answer 2 · answered Nov 30 '17 at 13:06

0

Since you want to write a shell script, use commands. To get date, use cut cmd like ex:

cat 1.txt 
R014-20171109-1159.log.20171109_1159
 cat 1.txt | cut -d "-" -f2

Output

20171109

is your date and create folder. This way you can loop and create as many folders as you want

answered Nov 30 '17 at 13:06

Ajay2588

527
3
6

Or just `cut -d "-" -f2 1.txt` to avoid a [very common bad habit](http://porkmail.org/era/unix/award.html) ;) – Sebastian Schmied Nov 30 '17 at 13:54

score 0 · Answer 3 · answered Nov 30 '17 at 13:12

Its actually quite easy(my Bash syntax might be a bit off) -

for f in /path/to/your/files*; do

## Check if the glob gets expanded to existing files.
## If not, f here will be exactly the pattern above
## and the exists test will evaluate to false.
[ -e "$f" ] && echo $f > #grep the file name for "*.log." 
#and extract 8 charecters after "*.log." .
#Next check if a folder exists already with the name of 8 charecters. 
#If not { create}
#else just move the file to that folder path

break
done

Main idea is from this post link. Sorry for not providing the actual code as i havent worked anytime recently on Bash

score 0 · Accepted Answer · answered Nov 30 '17 at 14:06

This is a typical application of a for-loop in bash to iterate thru files. At the same time, this solution utilizes GNU [ shell param substitution ].

for file in /path/to/files/*\.log\.*
do

  foldername=${file#*-}
  foldername=${foldername%%-*}
  mkdir -p "${foldername}" # -p suppress errors if folder already exists
  [ $? -eq 0 ] && mv "${file}" "${foldername}" # check last cmd status and move

done

How do i extract the date from multiple files with dates in it?

4 Answers4