Introduce function to purge invalid entries from history

README.md

@@ -45,7 +45,7 @@ For example, if you wish to launch your programs with `swaymsg exec`, you can do
  swaymsg exec "$(./sway-launcher-desktop.sh)"
 ```
 
-### Setup a Terminal command
+### Set up a Terminal command
 Some of your desktop entries will probably be TUI programs that expect to be launched in a new terminal window. Those entries have the `Terminal=true` flag set and you need to tell the launcher which terminal emulator to use. Pass the `TERMINAL_COMMAND` environment variable with your terminal startup command to the script to use your preferred terminal emulator. The script will default to `$TERMINAL -e`
 
 ### Configure application autostart
@@ -101,6 +101,12 @@ This history is stored in a file in `~/.cache/` (or `$XDG_CACHE_HOME`, if that e
 You may change the file path and name by setting the environment variable `HIST_FILE` to the desired path.
 Setting the variable to an empty value disables the history feature entirely.
 
+### Housekeeping
+After a while, this history might grow and contain some invalid entries due to removed/renamed programs etc.
+You can use `./sway-launcher-desktop.sh purge` to identify broken entries and remove them.
+Consider adding this command to a cronjob, startup script, or maybe even hook it into your package manager.
+
+
 ## Troubleshooting
 
 Debug information is directed to file descriptor `3` and can be dumped using `./sway-launcher-desktop.sh 3>> ~/sway-launcher-desktop.log`

sway-launcher-desktop.sh

@@ -23,30 +23,31 @@ if [[ "${PROVIDERS_FILE#/}" == "${PROVIDERS_FILE}" ]]; then
 fi
 
 # Provider config entries are separated by the field separator \034 and have the following structure:
-# list_cmd,preview_cmd,launch_cmd
+# list_cmd,preview_cmd,launch_cmd,purge_cmd
 declare -A PROVIDERS
 if [ -f "${PROVIDERS_FILE}" ]; then
   eval "$(awk -F= '
   BEGINFILE{ provider=""; }
   /^\[.*\]/{sub("^\\[", "");sub("\\]$", "");provider=$0}
-  /^(launch|list|preview)_cmd/{st = index($0,"=");providers[provider][$1] = substr($0,st+1)}
+  /^(launch|list|preview|purge)_cmd/{st = index($0,"=");providers[provider][$1] = substr($0,st+1)}
   ENDFILE{
     for (key in providers){
       if(!("list_cmd" in providers[key])){continue;}
       if(!("launch_cmd" in providers[key])){continue;}
       if(!("preview_cmd" in providers[key])){continue;}
+      if(!("purge_cmd" in providers[key])){providers[key]["purge_cmd"] = "exit 0";}
       for (entry in providers[key]){
        gsub(/[\x27,\047]/,"\x27\"\x27\"\x27", providers[key][entry])
       }
-      print "PROVIDERS[\x27" key "\x27]=\x27" providers[key]["list_cmd"] "\034" providers[key]["preview_cmd"] "\034" providers[key]["launch_cmd"] "\x27\n"
+      print "PROVIDERS[\x27" key "\x27]=\x27" providers[key]["list_cmd"] "\034" providers[key]["preview_cmd"] "\034" providers[key]["launch_cmd"] "\034" providers[key]["purge_cmd"] "\x27\n"
     }
   }' "${PROVIDERS_FILE}")"
   if [[ ! -v HIST_FILE ]]; then
     HIST_FILE="${XDG_CACHE_HOME:-$HOME/.cache}/${0##*/}-${PROVIDERS_FILE##*/}-history.txt"
   fi
 else
-  PROVIDERS['desktop']="${0} list-entries${DEL}${0} describe-desktop \"{1}\"${DEL}${0} run-desktop '{1}' {2}"
-  PROVIDERS['command']="${0} list-commands${DEL}${0} describe-command \"{1}\"${DEL}${TERMINAL_COMMAND} {1}"
+  PROVIDERS['desktop']="${0} list-entries${DEL}${0} describe-desktop \"{1}\"${DEL}${0} run-desktop '{1}' {2}${DEL}test -f {1}"
+  PROVIDERS['command']="${0} list-commands${DEL}${0} describe-command \"{1}\"${DEL}${TERMINAL_COMMAND} {1}${DEL}command -v {1}"
   if [[ ! -v HIST_FILE ]]; then
     HIST_FILE="${XDG_CACHE_HOME:-$HOME/.cache}/${0##*/}-history.txt"
   fi
@@ -250,8 +251,28 @@ function list-autostart() {
     ${DIRS[@]} </dev/null
 }
 
+purge() {
+ > "${HIST_FILE}"
+ declare -A PURGE_CMDS
+ for PROVIDER_NAME in "${!PROVIDERS[@]}"; do
+   readarray -td ${DEL} PROVIDER_ARGS <<<${PROVIDERS[${PROVIDER_NAME}]}
+   PURGE_CMD=${PROVIDER_ARGS[3]}
+   [ -z "${PURGE_CMD}" ] && PURGE_CMD='test -f {1}'
+   PURGE_CMDS[$PROVIDER_NAME]="${PURGE_CMD%$'\n'}"
+  done
+  for HIST_LINE in "${HIST_LINES[@]#*' '}"; do
+    readarray -td $'\034' HIST_ENTRY <<<${HIST_LINE}
+    ENTRY=${HIST_ENTRY[1]}
+    readarray -td ' ' FILTER <<<${PURGE_CMDS[$ENTRY]//\{1\}/${HIST_ENTRY[0]}}
+    "${FILTER[@]%$'\n'}" 1>/dev/null # Run filter command discarding output. We only want the exit status
+    if [[ $? -eq 0 ]]; then
+      echo "1 ${HIST_LINE[@]%$'\n'}" >> "${HIST_FILE}"
+    fi
+  done
+}
+
 case "$1" in
-describe | describe-desktop | describe-command | entries | list-entries | list-commands | list-autostart | generate-command | autostart | run-desktop | provide)
+describe | describe-desktop | describe-command | entries | list-entries | list-commands | list-autostart | generate-command | autostart | run-desktop | provide | purge)
   "$@"
   exit
   ;;

tests/history-purge.bats

@@ -0,0 +1,25 @@
+#!/usr/bin/env bats
+
+setup() {
+   export TERMINAL_COMMAND='urxvt -e'
+   export XDG_DATA_HOME=./data/desktop-files/0
+   export SLD_DESKTOP_ROOT="$XDG_DATA_HOME/applications/"
+   export XDG_CACHE_HOME=$BATS_TEST_TMPDIR
+   export XDG_CONFIG_HOME=./data/autostart-folders/0
+   export XDG_CONFIG_DIRS=./data/autostart-folders/1
+   export SLD_HIST_FILE="$BATS_TEST_TMPDIR/sway-launcher-desktop.sh-history.txt"
+   touch "$SLD_HIST_FILE"
+
+   echo "1 ${SLD_DESKTOP_ROOT}firefox.desktopdesktop  Firefox" >> "$SLD_HIST_FILE"
+   echo "1 ${SLD_DESKTOP_ROOT}cjsdalkcnjsaddesktop  I wanna be purged" >> "$SLD_HIST_FILE"
+   echo "1 awkcommand  awk" >> "$SLD_HIST_FILE"
+   echo "1 xksdkasjkslajdslakcommand  I wanna be purged" >> "$SLD_HIST_FILE"
+}
+
+@test "Purge command removes invalid entries" {
+  run ../sway-launcher-desktop.sh purge
+  readarray HIST_LINES <"$SLD_HIST_FILE"
+  cat "$SLD_HIST_FILE"
+  [ "$status" -eq 0 ]
+  [[ ${#HIST_LINES[@]} ==  2 ]]
+}