CODEWITHSUNDEEP
shell
Marc
Marc

Reputation: 1098

How to execute a command on multiple files with different extensions on the shell?

I would like to execute a command with the file names as parameter on all files in a directory with different file extensions. I tried this:

for i in *.jpg *.docx *.gdi; 
 do 
  mycommand dosth -i "$i" -o "${i%.*}.myext"; 
 done

But if one of the file extensions does not exist in the folder I get an error saying "file not found". How do I have to change the script?

Upvotes: 0

Views: 565

Answers (2)

chepner
chepner

Reputation: 532303

As Debian uses dash, there is no option for ignoring unmatched patterns. You can distinguish between a match result and an unmatched pattern by checking if a file named $i exists. If it does not, then it obviously was not the result of pathname expansion (which only produces existing files, race conditions aside.)

for i in *.jpg *.docx *.gdi
do 
    [ -e "$i" ] || continue  # E.g., if $i == "*.jpg" after no JPG files were found
    mycommand dosth -i "$i" -o "${i%.*}.myext"
done

In a Dockerfile, as the entire command has to be on one logical line, semicolons are necessary:

ENTRYPOINT for i in *.jpg *.docx *.gdi; do \
     [ -e "$i" ] || continue; \
     mycommand dosth -i "$i" -o "${i%.*}.myext"; \
    done

Upvotes: 1

0stone0
0stone0

Reputation: 44254

I'd recommend using to search for multiple extensions like so:

find . -type f \( -iname \*.jpg -o -iname \*.gdi -o -iname \*. docx \) -exec mycommand {} \;

The -exec can be altered with some more parameters if needed.
How to run find -exec?

Based on the commends, a solution thats spawns a shell so we can use substitution:

find . -type f \( -iname \*.jpg -o -iname \*.gdi -o -iname \*. docx \) -exec sh -c 'mycommand dosth -i "$0" -o "${0%.*}.myext"; ' {} \;

How to substitute string in {} in "find (...) -exec (...) {} \;" bash command?

Upvotes: 1

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