I need to search for a pattern (string) in all .tar archives and then append the names of archives which contains the pattern (string) provided in a text.txt folder. My code is:

for f in *.tar.gz 
  if [ -f "$f" ]; then
    found=$(tar -xvzf "$f" -O | grep -sE "$1")
    if [ ! -z "$found" ]; then
      echo "$f" >> text.txt


The problem is that I keep getting:

gzip:stdin:not in gzip format
tar:Child returned status 1
tar:Error is not recoverable:Exiting now
  • Your output indicates a data problem: not in gzip format. – user535733 May 22 at 21:38

Problem is in a file type. A file is not gz archive, but you tried to untar it tar -xvzf "$f". In your case, possible, it is tar, but with tar.gz extension.
Try to check type of files file your_file.tar.gz
Or try it for all tar.gz files

for f in *.tar.gz 
  if [ -f "$f" ]; then
    file "$f"

Result for gz archive should be my_file.tar.gz: gzip compressed data,...
If your files are tar archives, change tar -xvzf ... to tar -xvf ... in the script.

| improve this answer | |
  • I have only one tar archive on my current directory.I used your command and i get: pac.tar.gz :POSIX tar archive (GNU) – Nistor Mihnea May 23 at 8:54
  • @NistorMihnea, that means your file is tar, but not gz. In that case, you should change line 4 in your script. Instead "tar -xvzf", there should be "tar -xvf". Or, you can rename it to pac.tar (mv pac.tar.gz pac.tar), and make real gz by "gzip pac.tar". In that case, you do not need to change your script – Goran Paukovic May 23 at 10:23
  • Got it.The way i create tar archive is tar -cvf name.tar f1 f2 (f1 and f2 are folders).After i create this tar i should do gzip name.tar in order to use my script.If not i should use only tar -xvf right? – Nistor Mihnea May 23 at 11:12
  • True. Also, you can create a tar.gz archive in one step "tar -czvf file1 file2 file3 pac.tar.gz" – Goran Paukovic May 23 at 19:59
  • Understood.Thanks a lot, – Nistor Mihnea May 23 at 20:03

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