clipmanager

#!/bin/sh
history_dir="${XDG_CACHE_HOME:-$HOME/.cache}/clipboard_history/"
history_max_size=1000
pref_type="image/png
image/jpeg
image/bmp
x-special/gnome-copied-files
text/plain
"
default_string="UTF8_STRING"
log_to_file=1
log_file_path="${XDG_CACHE_HOME:-$HOME/.cache}/clipmanager.log"
lock_file_path="${XDG_CACHE_HOME:-$HOME/.cache}/clipmanager.lock"

history_current_size=0
disabled=0

log()
{
    if [ "$log_to_file" -ne 0 ]; then
        printf "%s\n" "$1" | xargs >> "$log_file_path"
    fi
    printf "\033[31m->\033[97m %s\033[0m\n" "$1" | xargs
}

# check if clipmanager is already running
if [ -d "$history_dir"  ]; then
    if [ -f "$lock_file_path" ]; then
        lock_file_pid=$(cat "$lock_file_path")
        if [ -d "/proc/$lock_file_pid" ] && [ "$(grep -o "^Name:.*$" "/proc/$lock_file_pid/status" | awk '{print $2}')" = "clipmanager" ]; then
            log "Clipmanager is already running"
            exit 1
        else
            rm -r "$history_dir"
        fi
    else
        rm -r "$history_dir"
    fi
fi

mkdir "$history_dir"
echo "$$" > "$lock_file_path"

# check if log file exists from previous session and rename it
if [ "$log_to_file" -ne 0 ] && [ -f "$log_file_path" ]; then
    mv "$log_file_path" "$log_file_path.old"
fi

dep_ck()
{
    for pr; do
        if ! command -v "$pr" >/dev/null 2>&1; then
            log "command $pr not found, install $pr"
            exit 1
        fi
    done
}
dep_ck "xclip" "sha256sum"

clean_up()
{
    rm -r "$history_dir"
    rm "$lock_file_path"
    exit
}

trap "exit" INT TERM
trap "clean_up" EXIT

trap "disabled=1" USR1
trap "disabled=0" USR2

log "$(basename "$0")"
log "----------"
while true; do
    # target check
    targets=$(xclip -selection clipboard -o -t TARGETS)
    targets_exit=$?
    log "TARGETS check: $targets_exit"

    if [ "$targets_exit" -ne 0 ]; then
# if target check fails wait for another copy event
        log "Waiting for selection with: $default_string"
        xclip -verbose -selection clipboard -t "$default_string" -in < /dev/null || exit 1
    else
# if target check succeeds take ownership of clipboard and create a history entry
        log "TARGETS clipboard: $targets"
        log "TARGETS preferred: $pref_type"
        log "TARGETS default: $default_string"

        # match target with the preferred ones
        grep_string=$(printf "%s" "$targets" | tr ' ' '|')
        first_found=$(printf "%s%s" "$pref_type" "$default_string" | grep -wEm1 "$grep_string")

        if [ -n "$first_found" ]; then
            log "TARGET found: $first_found"

            if [ "$disabled" -eq 0 ]; then
                # when clipboard data is text create a history entry
                if [ "$first_found" = "text/plain" ] || [ "$first_found" = "$default_string" ]; then
                    clipboard=$(xclip -verbose -selection clipboard -t "$first_found" -o)
                    clipboard_hash=$(printf "%s" "$clipboard" | sha256sum | cut -d" " -f1)

                    if [ ! -f "$history_dir/$clipboard_hash" ]; then
                        history_current_size=$((history_current_size + 1))
                        log "History: created text entry"
                    fi

                    printf "%s" "$clipboard" > "$history_dir/$clipboard_hash"
                fi

                if [ "$history_current_size" -gt "$history_max_size" ]; then
                    # delete the oldest history entry
                    rm "$(find "$history_dir" -type f -printf '%T+ %p\n' | sort | head -1 | sed 's/[^ ]* //')"
                    history_current_size=$((history_current_size - 1))
                    log "History: full, entry deleted"
                fi
            fi

            # preserve clipboard contents
            xclip -verbose -selection clipboard -t "$first_found" -o | xclip -verbose -selection clipboard -t "$first_found" -in
        else
            log "TARGET not found"
        fi
    fi
done