nnn/plugins/md5sum

#!/usr/bin/env sh

# Description: Create and verify md5 checksums
#
# If selection is used: it will generate one md5 file containing the checksums and file names
#                       [with paths if they are in another directory]
# If file is used: if the file is .md5 file, then it does the check
#                  if the file is not .md5 file, it creates the md5 file from it
#
# Shell: POSIX compliant
# Author: ath3

selection=~/.config/nnn/.selection
resp=f

if [ -s "$selection" ]; then
    echo -n "work with selection (s) or current file (f) [default=f]: "
    read resp
fi

if [ "$resp" = "s" ]; then
    arr=$(cat $selection | tr '\0' '\n')
    { read -r file; } <<< "$arr"
    file=$(basename "$file").md5
    cat "$selection" | sed 's|'"$PWD/"'||g' | xargs -0 -i md5sum {} > "$file"
else
    if ! [ -z "$1" ] && [ -f "$1" ]; then
        if [ $(echo $1 | grep \.md5$) ]; then
            cat "$1" | md5sum -c
            read
        else
            file=$(basename "$1").md5
            md5sum "$1" > "$file"
        fi
    fi
fi