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I found this answer how do i... but it simply doesn't work - it did not rename any file for unknown to me reason

Before I started to search around I thought that it should be easy task even for novice penguin, but it doesn't seem so for me.

For example, I simply can't tell ls to list all *.txt in all subfolders, which was surprise to me (without grep or similar).
Then I found find and find . -name name_1.txt lists files fine, but

for f in $(find . -name name_1.txt) ; do echo "$f" ; done

splits whole file paths with space as separator, so it's unusable to pass that output to some command like mv or rename

I want to ask whats wrong with above command and if possible some nifty oneliner so I can recursively rename name_1.txt to name_2.txt

Community
  • 1
zetah
  • 9,871

4 Answers4

12

find . -name '*.txt' -print0 | xargs -0 -n1 bash -c 'mv "$0" "${0/oldname/newname}"'

Obviously, that rename pattern is just a simple example, but beware that as is it will edit the whole path, not just the filename.

ams
  • 3,089
4

As @ams points out, many recursive replace solutions require you to work with the whole path, not just the file name.

I use find's -execdir action to solve this problem. If you use -execdir instead of -exec, the specified command is run from the subdirectory containing the matched file. So, instead of passing the whole path to rename, it only passes ./filename. That makes it much easier to write the replace command.

find /the/path -type f \
               -name '*_one.txt' \
               -execdir rename 's/\.\/(.+)_one\.txt$/$1_two.txt/' {} \;

In detail:

  • -type f means only look for files, not directories
  • -name '*_one.txt' means means only match filenames that end in _one.txt
  • In this answer, I'm using the rename command instead of mv. rename uses a Perl regular expression to rename each file.
  • The backslashes after -type and -name are the bash line-continuation character. I use them to make this example more readable, but they are not needed in practice.
  • However, the backslash at the end of the -execdir line is required. It is there to esacpe the semicolon, which terminates the command run by -execdir. Fun!

Explanation of the regex:

  • s/ start of the regex
  • \.\/ match the leading ./ that -execdir passes in. Use \ to escape the . and / metacharacters
  • (.+) match the start of the filename. The parentheses capture the match for later use
  • _one\.txt match "_one.txt", escape the dot metacharacter
  • $ anchor the match at the end of the string
  • / marks the end of the "match" part of the regex, and the start of the "replace" part
  • $1 references the existing filename, because we captured it with parentheses. If you use multiple sets of parentheses in the "match" part, you can refer to them here using $2, $3, etc.
  • _two.txt the new file name will end in "_two.txt". No need to escape the dot metacharacter here in the "replace" section
  • / end of the regex

Before

tree --charset=ascii

|-- a_one.txt
|-- b_one.txt
|-- Not_this.txt
`-- dir1
    `-- c_one.txt

After

tree --charset=ascii

|-- a_two.txt
|-- b_two.txt
|-- Not_this.txt
`-- dir1
    `-- c_two.txt

Hint: rename's -n option is useful. It does a dry run and shows you what names it will change, but does not make any changes.

Christian Long
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  • 16
4

the mmv command will do this in a rather simple call:

mmv ";name_1.txt" "#1name_2.txt"

The ";" wildcard, which is reused in the replacement filename as "#1" matches also subdirectories.

If you need more complicated examples, you should look into the man-page.

xubuntix
  • 5,580
0

You could explore the plethora of choices available:

`$ apt-cache search rename | grep -i rename`
waltinator
  • 37,856