How to rename/extract files with long names in zip archive

To extract

We can use zipinfo as a part of this process, it's a program from zip package.

zipinfo -2 example.zip

will only shows the files names in example.zip, something look like:

file1-long-name-...-bla-bla.html
file2-long-name-...-bla-bla.html

so we can use this feature to extract all files:

zipinfo -2 example.zip | while read i;
do
  long_fname=${i%.*}
  unzip -p -c example.zip "$i" > "${long_fname:0:250}.${i##*.}"
done;

• long_fname=${i%.*}: Removes extension from long file name, so in case of file name being less that of 256 character; We're not going to get a duplicate extension.
• ${long_fname:0:250}.${i##*.}: Creates a new file name with legitimate number of character also adds a . and file real extension.

Simply we are looping into files list and extract each of them with a new legitimate file name which is 256 character.

To rename

You can use zipnote command, it's a part of zip package too.

Get a backup of your zip file first.

Run this command:

zipnote example.zip > names

Open names using an editor, it's look like this:

@ file name long in zip and a lot of other strings in the file name
@ (comment above this line)
@ (zip file comment below this line)

Add new file names like this:

@ file name long in zip and a lot of other strings in the file name
@=new short name for above file
@ (comment above this line)
@ (zip file comment below this line)

Then to rename files use:

zipnote -w example.zip < names

You renamed them all, you can also write a simple script which do this automatically for you.

The other answer didn't work for me for some reason, even after decreasing the output file name to length 100, so instead I just extracted all files at once with unzip -p > all.txt and then split the file all.txt with csplit based on some pattern.

Note that unzip will add lines like

------=_Part_4952_1005066427.1638023175221

and

    boundary="----=_Part_4953_1221949914.1638023175221"

which should be removed from the output and probably used to split the file, but I didn't need to do that so how to do this properly is left as an exercise :)

Here is the version that handles long directory names as well. You can add it as a function to your ~/.bashrc or wherever you store your functions or aliases.

unziplong() {
    max_base_len=100
    max_ext_len=15
    zipinfo -1 "$1" | grep -v "/$" | while read orig_path
    do
        new_path=""
        current_path="$orig_path"
        while [[ "$current_path" != "." ]]
        do
            segment="$(basename -- "$current_path")"
            ext="$([[ "$segment" =~ .*\..{1,$max_ext_len}$ ]] && echo ".${segment##*.}" || echo)"
            base="${segment%$ext}"
            segment="/$(xargs <<< "${base:0:$max_base_len}")$(xargs <<< "$ext")"
            new_path="$segment$new_path"
            current_path="$(dirname -- "$current_path")"
        done
        new_path="${new_path:1}"
        new_dir="$(dirname -- "$new_path")"
        mkdir -p "$new_dir"
        unzip -p "$1" "$orig_path" > "$new_path"
    done
}