在Linux上使用sed输出的特定文件列表创建tar gz

Question

Here is my command line:

find . -type f -exec file {} \; \
| sed 's/\(.*png\): .* \([0-9]* x [0-9]*\).*/\2 \1/' \
| sed 's/\(.*jpg\): .* \([0-9]*x[0-9]*\).*/\2 \1/' \
| awk 'int($1) < 1000' \
| sed 's/^.*[[:blank:]]//' \
| tar -czvf images.tar.gz --null -T -

And the error i got is:

tar: Unix\\n./test.png\\n./test2.jpg\\n: Cannot stat: No such file or directory
tar: Exiting with failure status due to previous errors

What i want is to find all images in current directory, who's width less than 1000 px and tar them into archive.

Answer 1

to use --null , you need to convert newlines to nulls first:

...
| tr '\n' '\0' \
| tar -czvf images.tar.gz --null -T -

(tested, working.)

also, here are a number of suggestions on speed and style in decreasing order of importance.

a. don't find and run file on more files than you need to:

find . -type f -iname "*.png" -or -iname "*.jpg"

b. for commands that can run on multiple files per command, such as file , use xargs to save a lot of time:

find . -type f -iname "*.png" -or -iname "*.jpg" -print0 | xargs -0 file

c. if you put | at the end of each line, you can continue on the next line without also using \\ .

find . -type f -iname "*.png" -or -iname "*.jpg" -print0 |
  xargs -0 file

d. you can save yourself a lot of trouble since your max width is 999 by just grep ing for 1, 2, or 3 digit widths, though the awk '$1<1000' is ultimately better in case you ever want to use a different threshold:

find . -type f -iname "*.png" -or -iname "*.jpg" -print0 |
  xargs -0 file |
  grep ', [0-9][0-9]\?[0-9]\? x '

e. grep and awk are faster than sed , so use them where possible:

find . -type f -iname "*.png" -or -iname "*.jpg" -print0 |
  xargs -0 file |
  grep ', [0-9][0-9]\?[0-9]\? x ' |
  grep -o -i '.*\.\(png\|jpg\)'

final command:

find . -type f -iname "*.png" -or -iname "*.jpg" -print0 |
  xargs -0 file |
  grep ', [0-9][0-9]\?[0-9]\? x ' |
  grep -o -i '.*\.\(png\|jpg\)' |
  tr '\n' '\0' |
  tar -czvf images.tar.gz --null -T -

Answer 2

You can also use awk only with :

find . -type f \( -name "*.png" -or -name "*.jpg" \)  -exec file {} \; | awk -v width_limit=1000 '
    {
        match($0, /,\s+([0-9]+)\s*x\s*([0-9]+)/, items)

        if (items[1] < width_limit){
            match($0, /(.*):/, filename)
            print filename[1]
        }             
    }' | tar -czvf allfiles.tar -T -

The width can be configured with width_limit variable

Answer 3

Quick way using perl :

find . -type f -exec file {} + |
    perl -ne '
        print $1."\0" if /^(.*):\s*(JPEG|PNG).*,\s*(\d+)\s+x\s*\d+\s*,/ &&
             $3 < 1000;
        ' | tar -czvf images.tar.gz --null -T -

Using + operator to find as same effect than print0 | xargs -0 print0 | xargs -0 .