test for pilerexport and use found full path

.vscode/numbered-bookmarks.json

@@ -1,3 +1,19 @@
 {
-	"bookmarks": []
+	"bookmarks": [
+		{
+			"fsPath": "$ROOTPATH$/pilerBackup/pilerbackup.sh",
+			"bookmarks": [
+				-1,
+				328,
+				408,
+				-1,
+				-1,
+				-1,
+				-1,
+				-1,
+				-1,
+				645
+			]
+		}
+	]
 }

pilerBackup/pilerbackup.sh

@@ -322,6 +322,12 @@ done
 
 
 ### check pre-requisites and default values
+# find pilerexport, otherwise this is all pointless
+pilerExport=$( command -v pilerexport )
+if [ ! "$pilerExport" ]; then
+    printf "\n${err}ERROR: cannot find 'pilerexport'${norm}\n\n"
+    exit 4
+fi
 # does the details file exist?
 if [ ! -f "$configDetails" ]; then
     badParam dne "(--details default)" "$configDetails"
@@ -404,13 +410,13 @@ printf "\n${yellow}%s/${cyan} --${norm}\n" "$exportDir" >> "$logFile"
 printf "${cyan}[%s] -- [INFO] Exporting EML files from piler --${norm}\n" \
     "$(stamp)" >> "$logFile"
 if [ "$exportAll" -eq 1 ]; then
-    if ! pilerexport -A 2>>"$logFile"; then
+    if ! ${pilerExport} -A 2>>"$logFile"; then
         exitError 115 "There was a problem while exporting EML from piler"
     fi
     printf "${ok}[%s] -- [SUCCESS] Exported EML files from piler --${norm}\n" \
         "$(stamp)" >> "$logFile"
 else
-    if ! pilerexport -a "$exportStart" -b "$exportEnd" 2>>"$logFile"; then
+    if ! ${pilerExport} -a "$exportStart" -b "$exportEnd" 2>>"$logFile"; then
         exitError 115 "There was a problem while exporting EML from piler"
     fi
     printf "${ok}[%s] -- [SUCCESS] Exported EML files from piler --${norm}\n" \
@@ -637,6 +643,7 @@ exit 0
 # 1: parameter error
 # 2: not run as root
 # 3: borg not installed
+# 4: cannot find pilerexport executable
 # 99: TERM signal trapped
 # 111: could not create tmp dir for EML dump from piler-export
 # 112: could not set permissions on tmp dir