How to rename file name contains backslash in bash?

Question

I got a tar file, after extracting, there are many files naming like

a
b\c
d\e\f
g\h

I want to correct their name into files in sub-directories like

a
b/c
d/e/f
g/h

I face a problem when a variable contains backslash, it will change the original file name. I want to write a script to rename them.

Answer 1

Parameter expansion is the way to go. You have everything you need in bash, no need to use external tools like find.

$ touch a\\b c\\d\\e
$ ls -l
total 0
-rw-r--r--  1 ghoti  staff  0 11 Jun 23:13 a\b
-rw-r--r--  1 ghoti  staff  0 11 Jun 23:13 c\d\e
$ for file in *\\*; do
> target="${file//\\//}"; mkdir -p "${target%/*}"; mv -v "$file" "$target"; done
a\b -> a/b
c\d\e -> c/d/e

The for loop breaks out as follows:

• for file in *\\*; do - select all files whose names contain backslashes
• target="${file//\\//}"; - swap backslashes for forward slashes
• mkdir -p "${target%/*}"; - create the target directory by stripping the filename from $target
• mv -v "$file" "$target"; - move the file to its new home
• done - end the loop.

The only tricky bit here I think is the second line: ${file//\\//} is an expression of ${var//pattern/replacement}, where the pattern is an escaped backslash (\\) and the replacement is a single forward slash.

Have a look at man bash and search for "Parameter Expansion" to learn more about this.

---

Alternately, if you really want to use find, you can still take advantage of bash's Parameter Expansion:

find . -name '*\\*' -type f \
  -exec bash -c 't="${0//\\//}"; mkdir -p "${t%/*}"; mv -v "$0" "$t"' {} \;

This uses find to identify each file and process it with an -exec option that basically does the same thing as the for loop above. One significant difference here is that find will traverse subdirectories (limited by the -maxdepth option), so ... be careful.

Answer 2

Renaming a file with backslashes is simple: mv 'a\b' 'newname' (just quote it), but you'll need more than that.

You need to:

• find all files with a backslash (e.g. a\b\c)
• split path from filename (e.g. a\b from c)
• create a complete path (e.g. a/b, dir b under dir a)
• move the old file under a new name, under a created path (e.g. rename a\b\c to file named c in dir a/b)

Something like this:

#!/bin/bash
find . -name '*\\*' | while read f; do
    base="${f%\\*}"
    file="${f##*\\}"
    path="${base//\\//}"
    mkdir -p "$path"
    mv "$f" "$path/$file"
done

(Edit: correct handling of filenames with spaces)