2

I am trying to write a one line command to create 20 empty files with names extracted from a .txt file in another folder directory with the same txt extension.

I tried

for i in $(cat test.txt); do grep -w $i | touch $i.txt ; done

and

cat test.txt| while read line ; do grep $line ; touch $line.txt ; done

as well as

for filename in $(cat testfile.txt) ;  do touch head -20 $filename.txt; done

It does not work. I do not know how to specify the 10 first words of the test.txt file.

  • How about for i in $(head test.txt); do touch $i.txt ; done? – mikewhatever Oct 21 at 13:50
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    Please edit your question to include a minimal example of your test.txt file - the format matters e.g. whether there is one word per line, multiple words per line etc. – steeldriver Oct 21 at 13:55
  • ...or rather for i in $(head -n 20 test.txt); do touch $i.txt ; done, since you want 20 entries. – mikewhatever Oct 21 at 15:01
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    @Fred007... you mean 20 first words? – bac0n Oct 21 at 15:58
2

Does this work for you?

while IFS= read -r i; do
  touch "$i".txt
done < <(head -20 filename.txt)
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    Not sure why this was downvoted - although I'd suggest replacing the command substitution + here string with a process substitution + redirection i.e. done < <(head -20 filename.txt) and adding a -r to the read in case any of the filenames contain escapes. Arguably it should be while IFS= read -r i; do if we assume that any leading whitespace is intentional. I guess we should wait for clarification from the OP. – steeldriver Oct 21 at 15:03
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    I would use while IFS= read -r i – pa4080 Oct 21 at 17:39
2

Get first 20 words.

Using cut:

$ for i in $(cut -d ' ' -f1-20 a.txt); do touch $i.txt; done

(with mapfile):

$ mapfile -d ' ' -n 20 -t < a.txt; touch ${MAPFILE[@]/%/.txt}

(with awk):

$ awk '{for (i=1; i<=20; i++) {system("touch "$i".txt")}}' a.txt

(with shell parameter expansion):

$ a=($(<a.txt)); a=(${a[@]/%/.txt}); touch ${a[@]:0:19}
  • it worked thanks bac0n – Fred007 Oct 21 at 18:48
1

xargs command has --arg-file flag, which allows using arguments for a command you intend to run from file. Thus, you can do

xargs --arg-file=filenames.txt touch

If you want first 20 lines

head -n20 filenames.txt | xargs  touch

Substitute tail instead of head for last 20 lines from file

  • he wants 20 words. – bac0n Oct 22 at 6:16
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    @bac0n That's not been confirmed yet, but I'll edit my answer if that is in fact so – Sergiy Kolodyazhnyy Oct 22 at 6:40

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