How can we append asterisk (*) at the end of last line(content) of each and every text file within same directory in Ubuntu 20.10?

Question

I have many text files in a directory. I want to append/add * at the end of last line (content) of each and every text file of the directory with the extension .txt How can this be achieved in Ubuntu 20.10 in single operation?

Why I am asking this is because currently I am working on .txt and .pgn files. If I have to convert .txt to .pgn file then an *, 1/2-1/2, 1-0 or 0-1 is needed at the end of the last line, (signifying score or end of game to the machine) otherwise I will not be able to convert them to .pgn files. Also even if I convert them to .pgn files by save as, then also the file would still be incomplete and unreadable in machine binary that will be made out of it. Machine will not be able to identify it as a score or end.

Answer 1

This one should be able to do it to all your .txt files.

Run from the current folder that all your .txt files are in:

find . -maxdepth 1 -iname "*.txt" -print0 | xargs -L1 -0 sed -i '$a*'

That command will find all files even with spaces then append a * to the last line of all the .txt files found in that folder.

Hope this helps!

Answer 2

This can do the job for smaller numbers of files (around 1000 files):

echo "*" | tee -a *.txt >/dev/null

or use this for larger numbers of files:

for f in *.txt
    do
    echo "*" >> "$f"
    done

Run the above commands from the directory containing the .txt files.

Answer 3

You could go a step further and use the

    files

command to help you determine which files are ASCII text.

To that end, I've made a small shell script called addstar.sh in my home directory

    file $1 | grep ": ASCII text"  | sed "s/: ASCII text.*//g" |  echo "*" >> $1

when combined with the find command, you have a solution

    find  -maxdepth 1 -mindepth 1 -name "*.txt"  -exec  ~/addstar.sh {} \;

    

the -maxdepth and -mindepth parameters keep it to a single directory.

Regards, mondotofu

P.S. don't forget to

    chmod +x ~/addstar.sh

P.P.S Bear in mind that there are many kinds of text. Here's a quick scan of files in my home directory.

$ file * | grep "text"
addstar.sh:                                                        ASCII text
agent-install.log:                                                 UTF-8 Unicode text, with CRLF, CR, LF line terminators, with escape sequences
cantcopy.log:                                                      UTF-8 Unicode text, with very long lines
conda_install_altair.log:                                          ASCII text
conda_install_altair.log2:                                         ASCII text
conda_install_altair.log2~:                                        ASCII text
conf.yaml:                                                         ASCII text
files.list:                                                        ASCII text
fun_reports.txt:                                                   ASCII text
release-notes.html:                                                HTML document, UTF-8 Unicode text
stacktrace_20200724-1656.txt:                                      ASCII text, with CRLF, LF line terminators
T480_config-backup.sh:                                             ASCII text

You may need to adapt the one-shot command where I grep only for ASCII text and see whether you need to adapt it to kind other sorts of text output.