How to keep a filename with only 20 characters and a file extension .txt

filenamesrename

I have a bunch of files like this:

hhsLog.8020.20200330}1585594173}0}coll_DefaultCollectorGroup_1_158594166_132642}1036942}0}0

I just want to keep the first 20 characters and add a .txt extension. So in the end I should have a file with the name:

hhsLog.8020.20200330.txt

I am working on both Fedora and Solaris.

Best Answer

You can easily do this with a shell loop in bash:

cd /path/to/files/;
for file in *; do
    echo mv -i -- "$file" "${file:0:20}.txt"
done

Once you are satisfied that does what you need, remove the echo to actually rename the files:

 cd /path/to/files/;
 for file in *; do
    mv -i -- "$file" "${file:0:20}.txt"
done

The -i will make mv ask before overwriting if one of the new names already exists.

Related Solutions

Shell – Split a File by Line and Control Resulting File Extensions

Not with split, but you can easily rename them afterwards, or you can do it in awk:

awk '{filename = "wrd." int((NR-1)/10000) ".txt"; print >> filename}' inputfile

Shell – Backup file with .bak _before_ filename extension

Might be as simple as

cp file.{ext,bak.ext}

bash {} expansion expands to all combinations (unlike [] expantion which lists existing files. So it generates two file names.

The { .... , .... } provides two options, so you get file.ext and file.bak.ext

In your script you would use

cp $FILE.{$EXTENTION,bak.$EXTENTION}

And to break up the FILENAME into the two halves you can use

FILE=${FILENAME%.*}
EXTN=${FILENAME##*.}

${VAR%xxxxx} will return the left side of what is in VAR up to the matching pattern, in the case above the pattern is .* so you get everything except the last .*

${VAR##xxxxx} will return the right side of what is in VAR, after the matching pattern. The double hash means get the biggest possible match, in case there is more than one possble match.

To make your script save, check for cases where after obtaining FILE and EXTENTION, that they are not the same thing. This will happen in cases where the file name doesn't have an extention.

A sub-section of your script might look like this:

ls *html | while read FILENAME
do
    FILE=${FILENAME%.*}
    EXTN=${FILENAME##$FILE}
    cp $FILE{$EXTN,.bak$EXTN}
done

Best Answer

Related Solutions

Shell – Split a File by Line and Control Resulting File Extensions

Shell – Backup file with .bak _before_ filename extension

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