Check for required commands, cleanup, added help.

software/flash.sh

@@ -1,5 +1,20 @@
 #!/bin/bash
 
+set -eu
+
+check_command()
+{
+    name=$1
+    if ! command -v "$name" > /dev/null 2>&1; then
+        echo "'$name' is required, please install"
+        exit 1
+    fi
+}
+
+check_command udisksctl
+check_command lsusb
+check_command picotool
+
 DEVICEPATH=/dev/disk/by-label/RPI-RP2
 IMAGEPATH=lib/micropython/ports/rp2/build-TONBERRY_RPI_PICO_W/firmware.uf2
 
@@ -7,10 +22,6 @@ flash_via_mountpoint()
 {
     while [ ! -e "$DEVICEPATH" ] ; do sleep 1; echo 'Waiting for RP2...'; done
     
-    set -eu
-    
-    while [ ! -e "$DEVICEPATH" ] ; do sleep 1; echo 'Waiting for RP2...'; done
-    
     udisksctl mount -b "$DEVICEPATH"
     cp "$IMAGEPATH" "$(findmnt "$DEVICEPATH" -n -o TARGET)"
 }
@@ -21,10 +32,6 @@ VID="0003"
 flash_via_picotool()
 {
     while [ ! "$(lsusb -d $PID:$VID)" ] ; do sleep 1; echo 'Waiting for RP2 (USB)...'; done
-    
-    set -eu
-    
-    while [ ! "$(lsusb -d $PID:$VID)" ] ; do sleep 1; echo 'Waiting for RP2 (USB)...'; done
 
     local serial
     serial="$(lsusb -d $PID:$VID -v | grep "iSerial" | awk '{print $3}')"
@@ -41,13 +48,15 @@ FLASH_VIA_MOUNTPOINT=0
 usage()
 {
     echo "Usage: $0  [ -m | --via-mountpoint ]"
+    echo "                   [ -h | --help ]"
     echo
     echo "  -m, --via-mountpoint    Mount first found RP2 and flash image by"
     echo "                          copying to mountpoint."
+    echo "  -h, --help              Print this text and exit."
     exit 2
 }
 
-PARSED_ARGUMENTS=$(getopt -a -n "$0" -o m --long via-mountpoint -- "$@")
+PARSED_ARGUMENTS=$(getopt -a -n "$0" -o mh --long via-mountpoint,help -- "$@")
 # shellcheck disable=SC2181
 # Indirect getopt return value checking is okay here
 if [ "$?" != "0" ]; then
@@ -58,14 +67,15 @@ eval set -- "$PARSED_ARGUMENTS"
 while :
 do
     case "$1" in
-        -m | --via-mountpoint)   FLASH_VIA_MOUNTPOINT=1      ; shift   ;;
+        -m | --via-mountpoint)  FLASH_VIA_MOUNTPOINT=1      ; shift   ;;
+        -h | --help)            usage                                 ;;
         --) shift; break ;;
         *) echo "Unexpected option: $1"
            usage ;;
     esac
 done
 
-if [ "$1" ]; then
+if [ $# -gt 0 ]; then
     echo "Unexpected positional arguments: $1"
     usage
 fi