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

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

Answer 1

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

Answer 2

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

Answer 3

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

Answer 4

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}/