adb_wait_for_device: More fixes

platform_tools/android/bin/adb_wait_for_device

Index: platform_tools/android/bin/adb_wait_for_device
diff --git a/platform_tools/android/bin/adb_wait_for_device b/platform_tools/android/bin/adb_wait_for_device
index fc8a0f118dd5402ff2ec345104febf0be58c02d4..acf73b1bcc20942a7d9373eb9a50d44967577596 100755
--- a/platform_tools/android/bin/adb_wait_for_device
+++ b/platform_tools/android/bin/adb_wait_for_device
@@ -6,7 +6,9 @@ SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 source $SCRIPT_DIR/android_setup.sh
 source $SCRIPT_DIR/utils/setup_adb.sh
 
-function _get_battery_level {
+# Helper function used by get_battery_level. Parses the battery level from
+# dumpsys output.
+function _parse_battery_level {
   SPLIT=( $@ )
 
   HAS_BATTERY=1
@@ -18,7 +20,7 @@ function _get_battery_level {
     fi
     if [ "${SPLIT[$i]}" = "present:" ]; then
       PRESENT="$(echo "${SPLIT[$i+1]}" | tr -d '\r')"
-      if [ "$PRESENT" -eq "0" ]; then
+      if [ "$PRESENT" = "0" ]; then

[borenet, 2015/12/14 18:26:24]

Prevents error if PRESENT is not an integer, eg. "true" or "false"

         HAS_BATTERY=0
       fi
       if [ "$PRESENT" = "false" ]; then
@@ -36,10 +38,11 @@ function _get_battery_level {
   echo "100"
 }
 
+# Echo the battery level percentage of the attached Android device.
 function get_battery_level {
   STATS="$($ADB $DEVICE_SERIAL shell dumpsys batteryproperties)"
   SPLIT=( $STATS )
-  RV="$(_get_battery_level ${SPLIT[@]})"
+  RV="$(_parse_battery_level ${SPLIT[@]})"
   if [ -n "$RV" ]; then
     echo "$RV"
     return
@@ -49,7 +52,7 @@ function get_battery_level {
 
   STATS="$($ADB $DEVICE_SERIAL shell dumpsys battery)"
   SPLIT=( $STATS )
-  RV="$(_get_battery_level ${SPLIT[@]})"
+  RV="$(_parse_battery_level ${SPLIT[@]})"
   if [ "$RV" != "-1" ]; then
     echo "$RV"
     return