Making termux-x11-preference use options from stdin, updating readme.

README.md

@@ -167,6 +167,22 @@ Also you can start `termux-x11` with `-dpi` option.
 ~ $ termux-x11 :1 -xstartup "xfce4-session" -dpi 120
 ```
 
+## Changing, dumping and restoring preferences from commandline
+
+It is possible to change preferences of termux-x11 from command line.
+`termux-x11-nightly` package contains `termux-x11-preference` tool which can be used like 
+```shell
+termux-x11-preference [list] {key:value} [{key2:value2}]..."
+```
+
+Use `termux-x11-preference` to dump current preference.
+Use `termux-x11-preference > file` to dump current preferences to file.
+Use `termux-x11-preferences < file` to restore preferences from file.
+Use `termux-x11-preferences "fullscreen"="false" "showAdditionalKbd"="true"` to disable fullscreen and enable additional key bar. The full list of preferences you can modify is available with `termux-x11-preference list` command. You can specify one or more preferences here.
+
+Termux:X11 activity should be available in background or foreground, otherwise `termux-x11-preferences` tool will hang indefinitely.
+In the case if there is `Store preferences for secondary displays separately` preference active `termux-x11-preference` will use/modify preferences of display where Termux:X11 activity is currently opened.
+
 ## Using with 3rd party apps
 It is possible to use Termux:X11 with 3rd party apps.
 Check how `shell-loader/src/main/java/com/termux/x11/Loader.java` works.

termux-x11-preference

@@ -1,7 +1,7 @@
 #!/data/data/com.termux/files/usr/bin/bash
 COMMAND=("am" "broadcast" "-a" "com.termux.x11.CHANGE_PREFERENCE" "-p" "com.termux.x11")
 help() {
-  echo "$0 {list} {key:value}..."
+  echo "$0 [list] {key:value} [{key2:value2}]..."
   exit 1
 }
 
@@ -22,7 +22,20 @@ list() {
 }
 
 if [ $# -eq 0 ]; then
-  help
+  if [ -t 0 ]; then
+    help
+  else
+    OLD_LENGTH="${#COMMAND[@]}"
+    while IFS= read -r line || [[ -n "$line" ]]; do
+      [ -z "$line" ] && continue
+      key=$(echo "$line" | sed -E 's/^"([^"]+)".*/\1/')
+      value=$(echo "$line" | sed -E 's/^"[^"]+"="(.*)"/\1/')
+      COMMAND+=("-e" "$key" "$value")
+    done
+    if [[ "$OLD_LENGTH" == "${#COMMAND[@]}" ]]; then
+      help
+    fi
+  fi
 fi
 
 while [[ $# -gt 0 ]]; do