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bashfilenamesparentheses

Parenthesis in a file name -- batch conversion

I have a bunch of files that contain parenthesis, like

long_file_name (12).txt

(note the space before the number) I would like to extract all the numbers from the file names. How can I do that? I have found this thread stackoverflow link but it didn't help -- the problem is that I want to assign filename to a variable and not change each of the files separately.

Thanks for all help

Solution

  • You can do this in bash by using the variable interpolation/substitution:

    $ F="long_file_name (12).txt"
$ echo ${F/*(/}
12).txt
$ G=${F/*(/}; echo ${G/)*/}
12
$ G=${F/*(/}; H=${G/)*/}; echo $H
12
$

    In short, this will give you just the number in parentheses from a filename:

    F="long_file_name (12).txt"
G=${F/*(/}; H=${G/)*/}; echo $H

    If you have filenames in other formats, please supply more examples to test with.