Rename a bunch of file by replacing a number in the filename by a coresponding string from a textfile

Question

I have a large number of files I want to rename. Each filename contains a number (xxx): FIXED_PART_xxx_UNIQUE_PART.

I also have a text file, which has a number and a string in each line:

001 string001
002 string002
...
112 string112

there is an entry for each file, but not necessarily a file for each entry. I want to rename each file by parsing the xxx part and replacing it with the string from the file.

What is the best way to do that?

edit: the actual file names look like this:

Berlin_Ost_034_some_variable_text.jpg

so the fixed part contains also an underscore in this case, but it is the same for each folder. The xxx part consists only of numbers.

the output would be for this file

Berlin_Ost_Sommer_some_variable_text.jpg

and I am talking about 200 files

The text file contains a line: 034 Sommer

which is why the 034 part in the file gets replaced by Sommer

The file contains all sorts of strings, but only characters and numbers and german umlauts. The first part is always a number. Here is a part from one of the files I am using

033 Winter
034 Sommer
035 Herbst
036 Frühling
037 Abends.kurz.vor.Sonnenaufgang

I am using linux

Answer 1

With zsh and assuming the strings don't contain space or tab characters:

autoload -Uz zmv
typeset -A mapping=($(<mapping.txt))
zmv -n '(*_)([0-9](#c3))(_*.jpg)' '$1${mapping[$2]-$2}$3'

Remove the -n (dry-run) if happy.

For file names that contain more than one sequence of 3 digits between underscores, the right-most one will be replaced. Using ${mapping[$2]-$2} ensures that if that sequence of digits is not found in the mapping, then it will be left asis.

If all files have the same prefix, you can also do:

zmv -n '(Berlin_Ost_)([0-9](#c3))(_*.jpg)' '$1${mapping[$2]-$2}$3'

If the strings may contain spaces or blanks (other than at the beginning or end), you can build the associative array as:

typeset -A mapping
while read -r key value; do mapping[$key]=$value; done < mapping.txt

instead.

To replace all occurrences of 3 digits in file names, you can do:

zmv -n '*.jpg' '${f//(#m)[0-9](#c3)/${mapping[$MATCH]-$MATCH}'

In that case, we don't look for underscore on either sides. We could do:

zmv -n '*.jpg' '${f//(#b)_([0-9](#c3))_/${mapping[$match[1]]-$match[1]}'

But while that would replace both 001 and 002 in foo_001_bar_002_baz.jpg, that woudn't in foo_001_002_bar.jpg as the second _ would be included in the first match and so couldn't be part of later matches.

Answer 2

You can iterate across each entry in your list of strings, renaming any matching files. This can be squashed into a single line but I've left it open here so I can append comments:

while IFS=' ' read -r key value                            # Extract the key and value
do
    for file in *_"$key"_*                                 # Loop across all matches
    do
        [ -f "$file" ] &&
            mv -- "$file" "${file/_${key}_/_${value}_}"    # Replace key with value
    done
done <keysandvalues                                        # Read the file of matches

The replacement expression will replace only the first occurrence of the key, and it must be bounded by underscore on both sides. Neither the key nor the value may contain /.

A side-effect of iterating across the file of replacements is that if you have a file name containing two replacement strings (for example, Berlin_033_other_035_text.jpg) then both will be replaced as they are matched (resulting here in Berlin_Winter_other_Herbst_text.jpg). Moving renamed files to a separate directory could work around this issue if it's a problem.

Answer 3

Here's a solution assuming _some_variable_text doesn't contain numbers:

$ for i in *.jpg; do
    s="$(grep "${i//[^0-9]/}" file.txt)"
    echo mv -- "$i" "${i//[0-9]*/}${s//* /}_${i//*[0-9]_/}"
    # to actually perform the command remove the echo
    # do a backup first
  done
mv -- Berlin_Ost_034_some_variable_text.jpg Berlin_Ost_Sommer_some_variable_text.jpg

---

• Loop through the files.
• s="$(grep "${i//[^0-9]/}" file.txt)" extract the key;
• mv -- "$i" "${i//[0-9]*/}${s//* /}_${i//*[0-9]_/}" rename the file using parameter substitution to get the different parts of the file name.

Answer 4

One line

prefix="foo" ls | grep -oP "(?<=${prefix}_).*" | xargs -I % sh -c 'mv ${prefix}_% ${prefix}_$( echo % | cut -d"_" -f1 | grep -f - filenames.txt | cut -d" " -f2 )_$( echo % | cut -d"_" -f2- ) '

where foo is the prefix (FIXED_PART) and filenames.txt the file with the names...

explanations:

it gets all the filenames starting with prefix in the curent directory, but match only the part after the prefix grep -oP "(?<=${prefix}_).*". For each of these lines (1) ,it renames file prefix+(1) to prefix+(search in the file for the first part of (1), and get the corresponding string)+remaining part of (1)

Et voilà