Python-сообщество

get_paths()
{
    find "$1" 2>/dev/null
}

paths_filter_files()
{
    while read line; do
        [ -f "$line" ] && echo "$line"
    done
}

files_filter_exts()
{
    local exts=${1//|/\\|}

    grep '\.\('"$exts"'\)$'
}

exclude_dirs()
{
    local dirs=${1//|/\\|}
    
    grep -v '/'"$dirs"'/'
}

search_exts_in_directory()
{
    local dir=$1
    local exts=$2

    get_paths "$dir" | paths_filter_files | files_filter_exts "$exts"
}

files_filter_by_content_icase()
{
    local contents=${1//|/\\|}

    while read line; do
        grep -q -i "$contents" "$line" 2>/dev/null && echo "$line"
    done

}

ymd()
{
    date '+%Y-%m-%d'
}

make_backup_name()
{
    sed 's/$/'".$(ymd).backup"'/'
}

make_backup()
{
    local src=$1
    local dst=$2

    while [ -e "$dst" ]; do
        dst="${dst}_"
    done
    cp "$src" "$dst"
}

replace_in_file_icase()
{
    local fname=$1
    local pat=$2
    local rep=$3

    sed -i 's/'"$pat"'/'"$rep"'/ig' "$fname"
}

convert_with_backup()
{
    local pattern=${1//|/\\|}
    local replacement=$2
    local backup_name

    while read line; do
        backup_name=$(echo "$line" | make_backup_name)
        make_backup "$line" "$backup_name"
        replace_in_file_icase "$line" "$pattern" "$replacement"
        echo "$line"
    done
}

main()
{
    search_exts_in_directory /tmp/test "txt|xml" | \
        exclude_dirs "dir1|dir2" | \
        files_filter_by_content_icase "user|server" | \
        convert_with_backup "test1|test2" "testtest" >/dev/null
}

main

convert_with_backup "@[^ ]*mycompany[12]\.com" "@mycompany3.com"