clipmenud
#!/usr/bin/env bash
: "${CM_ONESHOT=0}"
: "${CM_OWN_CLIPBOARD=0}"
: "${CM_DEBUG=0}"
: "${CM_DIR="${XDG_RUNTIME_DIR-"${TMPDIR-/tmp}"}"}"
: "${CM_MAX_CLIPS=1000}"
# Buffer to batch to avoid calling too much. Will only be used if CM_MAX_CLIPS
# > 0.
CM_MAX_CLIPS_THRESH=$(( CM_MAX_CLIPS + 100 ))
# Shellcheck is mistaken here, this is used later as lowercase.
# shellcheck disable=SC2153
: "${CM_SELECTIONS=clipboard primary}"
major_version=6
cache_dir=$CM_DIR/clipmenu.$major_version.$USER/
cache_file=$cache_dir/line_cache
# lock_file is the lock for *one* iteration of clipboard capture/propagation.
# session_lock_file is the lock to prevent multiple clipmenud daemons from
# running at once.
lock_file=$cache_dir/lock
session_lock_file=$cache_dir/session_lock
lock_timeout=2
has_clipnotify=0
has_xdotool=0
# This comes from the environment, so we rely on word splitting.
# shellcheck disable=SC2206
cm_selections=( $CM_SELECTIONS )
if command -v timeout >/dev/null 2>&1; then
timeout_cmd=(timeout 1)
else
echo "WARN: No timeout binary. Continuing without any timeout on xsel." >&2
timeout_cmd=()
fi
_xsel() {
"${timeout_cmd[@]}" 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() {
# Args:
# - , the file or data
# - , optional, the line length limit
data=${1?}
line_length_limit=${2-300}
# We look for the first line matching regex /./ here because we want the
# first line that can provide reasonable context to the user. That is, if
# you have 5 leading lines of whitespace, displaying " (6 lines)" is much
# less useful than displaying "foo (6 lines)", where "foo" is the first
# line in the entry with actionable context.
awk -v limit="$line_length_limit" '
BEGIN { printed = 0; }
printed == 0 && NF {
{{&blob}} = substr({{&blob}}, 0, limit);
printf("%s", {{&blob}});
printed = 1;
}
END {
if (NR > 1) {
print " (" NR " lines)";
} else {
printf("\n");
}
}' <<< "$data"
}
debug() {
if (( CM_DEBUG )); then
printf '%s\n' "$@" >&2
fi
}
element_in() {
local item element
item=""
for element in "${@:2}"; do
if [[ "$item" == "$element" ]]; then
return 0
fi
done
return 1
}
if [[ == --help ]] || [[ == -h ]]; then
cat << 'EOF'
clipmenud is the daemon that collects and caches what's on the clipboard.
when you want to select a clip.
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 + 100, 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")
- $CM_IGNORE_WINDOW: disable recording the clipboard in windows where the windowname matches the given regex (e.g. a password manager), do not ignore any windows if unset or empty (default: unset)
EOF
exit 0
fi
# It's ok that this only applies to the final directory.
# shellcheck disable=SC2174
mkdir -p -m0700 "$cache_dir"
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
declare -A last_filename
declare -A last_cache_file_output
command -v clipnotify >/dev/null 2>&1 && has_clipnotify=1
if ! (( has_clipnotify )); then
echo "WARN: Consider installing clipnotify for better performance." >&2
echo "WARN: See https://github.com/cdown/clipnotify." >&2
fi
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"
sleep_cmd=(sleep "${CM_SLEEP:-0.5}")
while true; do
if ! (( CM_ONESHOT )); then
if (( has_clipnotify )); then
# Fall back to polling if clipnotify fails
clipnotify || "${sleep_cmd[@]}"
else
# Use old polling method
"${sleep_cmd[@]}"
fi
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" "$lock_fd"; then
if (( CM_ONESHOT )); then
die 1 "Timed out waiting for lock"
else
error "Timed out waiting for lock, skipping this iteration"
continue
fi
fi
for selection in "${cm_selections[@]}"; do
data=$(_xsel -o --"$selection"; printf x)
debug "Data before stripping: $data"
# We add and remove the x so that trailing newlines are not stripped.
# Otherwise, they would be stripped by the very nature of how POSIX
# defines command substitution.
data=${data%x}
debug "Data after stripping: $data"
if [[ $data != *[^[:space:]]* ]]; then
debug "Skipping as clipboard is only blank"
continue
fi
if [[ ${last_data[$selection]} == "$data" ]]; then
debug 'Skipping as last selection is the same as this one'
continue
fi
# If we were in the middle of doing a selection when the previous poll
# ran, then we may have got a partial clip.
possible_partial=${last_data[$selection]}
if [[ $possible_partial && $data == "$possible_partial"* ]] ||
[[ $possible_partial && $data == *"$possible_partial" ]]; then
info "Last clip for $selection was a possible partial, removing line cache entry"
debug "$selection: $possible_partial is a possible partial of $data"
previous_size=$(wc -c <<< "${last_cache_file_output[$selection]}")
truncate -s -"$previous_size" "$cache_file"
file=${last_filename[$selection]}
# Don't remove the file yet, because it might be referenced by an
# older entry. These will be dealt with at vacuum time.
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_data[$selection]=$data
last_filename[$selection]=$filename
# Recover without restart if we deleted the entire clip dir.
# It's ok that this only applies to the final directory.
# shellcheck disable=SC2174
mkdir -p -m0700 "$cache_dir"
debug "Writing $data to $filename"
printf '%s' "$data" > "$filename"
debug "Writing $cache_file_output to $cache_file"
printf '%s\n' "$cache_file_output" >> "$cache_file"
last_cache_file_output[$selection]=$cache_file_output
if (( CM_OWN_CLIPBOARD )) && [[ $selection != primary ]] &&
element_in clipboard "${cm_selections[@]}"; then
# Take ownership of the clipboard, in case the original application
# is unable to serve the clipboard request (due to being suspended,
# etc).
#
# Primary is excluded from the change of ownership as applications
# sometimes act up if clipboard focus is taken away from them --
# for example, urxvt will unhilight text, which is undesirable.
#
# We can't colocate this with the above copying code because
# https://github.com/cdown/clipmenu/issues/34 requires knowing if
# we would skip first.
_xsel -o --clipboard | _xsel -i --clipboard
fi
done
# Fail quickly if we're not far enough over, to avoid calling `cksum` a
# lot and killing perf if we're not batched.
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.
info "Vacuuming unreferenced clip files"
while IFS= read -r line; do
cksum=$(cksum <<< "$line")
cksums["$cksum"]="$line"
done < <(cut -d' ' -f2- < "$cache_file")
for file in "$cache_dir"/[012346789]*; do
cksum=${file##*/}
line=${cksums["$cksum"]-_missing_}
if [[ $line == _missing_ ]]; then
debug "Vacuuming due to lack of reference: $file"
rm -- "$file"
fi
done
fi
flock -u "$lock_fd"
if (( CM_ONESHOT )); then
debug 'Oneshot mode enabled, exiting'
break
fi
done