clipmenud
#!/usr/bin/env bash
: "${CM_ONESHOT=0}"
: "${CM_OWN_CLIPBOARD=0}"
: "${CM_SYNC_PRIMARY_TO_CLIPBOARD=0}"
: "${CM_DEBUG=0}"
: "${CM_MAX_CLIPS:=1000}"
# Buffer to batch to avoid calling too much. Only used if CM_MAX_CLIPS >0.
CM_MAX_CLIPS_THRESH=$(( CM_MAX_CLIPS + 10 ))
: "${CM_SELECTIONS:=clipboard primary}"
read -r -a selections <<< "$CM_SELECTIONS"
cache_dir=$(clipctl cache-dir)
cache_file=$cache_dir/line_cache
status_file=$cache_dir/status
# lock_file: lock for *one* iteration of clipboard capture/propagation
# session_lock_file: lock to prevent multiple clipmenud daemons
lock_file=$cache_dir/lock
session_lock_file=$cache_dir/session_lock
lock_timeout=2
has_xdotool=0
_xsel() { timeout 1 xsel --logfile /dev/null "$@"; }
error() { printf 'ERROR: %s\n' "${1?}" >&2; }
info() { printf 'INFO: %s\n' "${1?}"; }
die() {
error "${2?}"
exit "${1?}"
}
make_line_cksums() { while read -r line; do cksum <<< "${line#* }"; done; }
get_first_line() {
data=${1?}
# We look for the first line matching regex /./ here because we want the
# first line that can provide reasonable context to the user.
awk -v limit=300 '
BEGIN { printed = 0; }
printed == 0 && NF {
{{&blob}} = substr({{&blob}}, 0, limit);
printf("%s", {{&blob}});
printed = 1;
}
END {
if (NR > 1)
printf(" (%d lines)", NR);
printf("\n");
}' <<< "$data"
}
debug() { (( CM_DEBUG )) && printf '%s\n' "$@" >&2; }
sig_disable() {
if (( _CM_DISABLED )); then
info "Received disable signal but we're already disabled, so doing nothing"
return
fi
info "Received disable signal, suspending clipboard capture"
_CM_DISABLED=1
echo "disabled" > "$status_file"
}
sig_enable() {
if ! (( _CM_DISABLED )); then
info "Received enable signal but we're already enabled, so doing nothing"
return
fi
# Still store the last data so we don't end up eventually putting it in the
# clipboard if it wasn't changed
for selection in "${selections[@]}"; do
data=$(_xsel -o --"$selection"; printf x)
last_data_sel[$selection]=${data%x}
done
info "Received enable signal, resuming clipboard capture"
_CM_DISABLED=0
echo "enabled" > "$status_file"
}
kill_background_jobs() {
# While we usually _are_, there are no guarantees that we're the process
# group leader. As such, all we can do is look at the pending jobs. Bash
# avoids a subshell here, so the job list is in the right shell.
local bg
bg=$(jobs -p)
# Don't log `kill' failures, since with KillMode=control-group, we're
# racing with init.
[[ $bg ]] && kill -- "$bg" 2>/dev/null
}
if [[ == --help ]] || [[ == -h ]]; then
cat << 'EOF'
clipmenud collects and caches what's on the clipboard. You can manage its
operation with clipctl.
Environment variables:
- $CM_DEBUG: turn on debugging output (default: 0)
- $CM_DIR: specify the base directory to store the cache dir in (default: $XDG_RUNTIME_DIR, $TMPDIR, or /tmp)
- $CM_MAX_CLIPS: soft maximum number of clips to store, 0 for inf. At $CM_MAX_CLIPS + 10, the number of clips is reduced to $CM_MAX_CLIPS (default: 1000)
- $CM_ONESHOT: run once immediately, do not loop (default: 0)
- $CM_OWN_CLIPBOARD: take ownership of the clipboard. Note: this may cause missed copies if some other application also handles the clipboard directly (default: 0)
- $CM_SELECTIONS: space separated list of the selections to manage (default: "clipboard primary")
- $CM_SYNC_PRIMARY_TO_CLIPBOARD: sync selections from primary to clipboard immediately (default: 0)
- $CM_IGNORE_WINDOW: disable recording the clipboard in windows where the windowname matches the given regex (e.g. a password manager), do not ignore any windows if unset or empty (default: unset)
EOF
exit 0
fi
[[ $DISPLAY ]] || die 2 'The X display is unset, is your X server running?'
# It's ok that this only applies to the final directory.
# shellcheck disable=SC2174
mkdir -p -m0700 "$cache_dir"
echo "enabled" > "$status_file"
exec {session_lock_fd}> "$session_lock_file"
flock -x -n "$session_lock_fd" ||
die 2 "Can't lock session file -- is another clipmenud running?"
declare -A last_data_sel
declare -A updated_sel
command -v clipnotify >/dev/null 2>&1 || die 2 "clipnotify not in PATH"
command -v xdotool >/dev/null 2>&1 && has_xdotool=1
if [[ $CM_IGNORE_WINDOW ]] && ! (( has_xdotool )); then
echo "WARN: CM_IGNORE_WINDOW does not work without xdotool, which is not installed" >&2
fi
exec {lock_fd}> "$lock_file"
trap '_CM_TRAP=1; sig_disable' USR1
trap '_CM_TRAP=1; sig_enable' USR2
trap 'trap - INT TERM EXIT; kill_background_jobs; exit 0' INT TERM EXIT
while true; do
if ! (( CM_ONESHOT )); then
# Make sure we're interruptible for the sig_{en,dis}able traps
clipnotify &
_CM_CLIPNOTIFY_PID="$!"
wait "$_CM_CLIPNOTIFY_PID"
fi
# Trapping a signal breaks the `wait`
if (( _CM_TRAP )); then
# Prevent spawning another clipnotify job restarting the loop
kill_background_jobs
unset _CM_TRAP
continue
fi
if (( _CM_DISABLED )); then
info "Got a clipboard notification, but we are disabled, skipping"
continue
fi
if [[ $CM_IGNORE_WINDOW ]] && (( has_xdotool )); then
windowname="$(xdotool getactivewindow getwindowname)"
if [[ "$windowname" =~ $CM_IGNORE_WINDOW ]]; then
debug "ignoring clipboard because windowname \"$windowname\" matches \"${CM_IGNORE_WINDOW}\""
continue
fi
fi
if ! flock -x -w "$lock_timeout" "$lock_fd"; then
if (( CM_ONESHOT )); then
die 1 "Timed out waiting for lock"
else
error "Timed out waiting for lock, skipping this iteration"
continue
fi
fi
for selection in "${selections[@]}"; do
updated_sel[$selection]=0
data=$(_xsel -o --"$selection"; printf x)
data=${data%x} # avoid trailing newlines being stripped
[[ $data == *[^[:space:]]* ]] || continue
[[ $last_data == "$data" ]] && continue
[[ ${last_data_sel[$selection]} == "$data" ]] && continue
if [[ $last_data && $data == "$last_data"* ]] ||
[[ $last_data && $data == *"$last_data" ]]; then
# Don't actually remove the file yet, because it might be
# referenced by an older entry. These will be dealt with at vacuum.
debug "$selection: $last_data is a possible partial of $data"
previous_size=$(wc -c <<< "$last_cache_file_output")
truncate -s -"$previous_size" "$cache_file"
fi
first_line=$(get_first_line "$data")
debug "New clipboard entry on $selection selection: \"$first_line\""
cache_file_output="$(date +%s%N) $first_line"
filename="$cache_dir/$(cksum <<< "$first_line")"
last_cache_file_output=$cache_file_output
last_data=$data
last_data_sel[$selection]=$data
updated_sel[$selection]=1
debug "Writing $data to $filename"
printf '%s' "$data" > "$filename"
debug "Writing $cache_file_output to $cache_file"
printf '%s\n' "$cache_file_output" >> "$cache_file"
if (( CM_OWN_CLIPBOARD )) && [[ $selection == clipboard ]]; then
# Only clipboard, since apps like urxvt will unhilight for PRIMARY
_xsel -o --clipboard | _xsel -i --clipboard
fi
done
if (( CM_SYNC_PRIMARY_TO_CLIPBOARD )) && (( updated_sel[primary] )); then
_xsel -o --primary | _xsel -i --clipboard
fi
# The cache file may not exist if this is the first run and data is skipped
if (( CM_MAX_CLIPS )) && [[ -f "$cache_file" ]] && (( "$(wc -l < "$cache_file")" > CM_MAX_CLIPS_THRESH )); then
info "Trimming clip cache to CM_MAX_CLIPS ($CM_MAX_CLIPS)"
trunc_tmp=$(mktemp)
tail -n "$CM_MAX_CLIPS" "$cache_file" | uniq > "$trunc_tmp"
mv -- "$trunc_tmp" "$cache_file"
# Vacuum up unreferenced clips. They may either have been
# unreferenced by the above CM_MAX_CLIPS code, or they may be old
# possible partials.
declare -A cksums
while IFS= read -r line; do
cksum=$(cksum <<< "$line")
cksums["$cksum"]="$line"
done < <(cut -d' ' -f2- < "$cache_file")
num_vacuumed=0
for file in "$cache_dir"/[012346789]*; do
cksum=${file##*/}
if [[ ${cksums["$cksum"]-_missing_} == _missing_ ]]; then
debug "Vacuuming due to lack of reference: $file"
(( ++num_vacuumed ))
rm -- "$file"
fi
done
unset cksums
info "Vacuumed $num_vacuumed clip files."
fi
flock -u "$lock_fd"
(( CM_ONESHOT )) && break
done