creating text file with regards to file names

Question

I have a text file (digit.txt) consisting of one column includes three digit numbers whose range are 001-...365. In the same directory, I have data text files. The file name of these data files as follows, jplg3240.18i. Only the jplg part is constant. I need to order jplg data files w.r.t. the numbers in the digit.txt file using the first 5-7 characters of the file names and store them in another text file. For example:

digit.txt=
005
301
350
005
010

data files= jplg001.18i.txt, jplg005.18i.txt, jplg301.18i.txt, jplg350.18i.txt,jplg010.18i.txt, jplg365.18i.txt

Output file should be this one:

output=
jplg005.18i
jplg301.18i
jplg350.18i
jplg005.18i
jplg010.18i

Answer 1

here the while cycle could be good for reach your goal:

while read element
do
    if [ -f jplg${element}* ]; then
        echo jplg${element}* >> datafiles.txt
    fi
done < digit.txt

Code is supposed to be run in to the path were the files are and give you as per result a file list in the file datafiles.txt with the complete name of the file if was matched in the list in the file digit.txt

Answer 2

If you question is concatenate the data from the files listed in digit.txt then an answer is:

ls jplg* | grep -f digit.txt | xargs cat >out.dat

In slo-mo:

• ls jplg*: lists a superset of all the files you want (you can make that more restrictive if needed)
• grep -f digit.txt keeps only the lines that contain one number in digit.txt (this assumes that the three digits don't appear anywhere else in file names)
• xargs cat: applies cat to all the files listed in the grep output