func badParam to handle missing or invalid params

backup_new.sh

@@ -18,6 +18,20 @@ mag="\e[95m"
 
 ### functions
 
+# bad parameter passed to script
+badParam () {
+    if [ "$1" = "empty" ]; then
+        printf "${err}\nError: '%s' cannot have a NULL (empty) value.\n" "$2"
+        printf "${cyan}Please use '--help' for assistance${normal}\n\n"
+        exit 1
+    elif [ "$1" = "dne" ]; then
+        printf "${err}\nError: '%s %s'\n" \
+            "$2" "$3"
+        printf "file or directory does not exist.\n\n"
+        exit 1
+    fi
+}
+
 # control seafile services (systemd)
 seafSvc () {
     if [ "$1" = "start" ]; then
@@ -90,7 +104,7 @@ while [ $# -gt 0 ]; do
                 logFile="${2%/}"
                 shift
             else
-                badParam "$@"
+                badParam empty "$@"
             fi
             ;;
         -v|--verbose)
@@ -101,10 +115,14 @@ while [ $# -gt 0 ]; do
         -c|--config|--details)
             # location of config details file
             if [ -n "$2" ]; then
+                if [ -f "$2" ]; then
                     configDetails="${2%/}"
                     shift
                 else
-                badParam "$@"
+                    badParam dne "$@"
+                fi
+            else
+                badParam empty "$@"
             fi
             ;;
         -5|--503)
@@ -114,7 +132,7 @@ while [ $# -gt 0 ]; do
                 err503File="${2##*/}"
                 shift
             else
-                badParam "$@"
+                badParam empty "$@"
             fi
             ;;
         -w|--webroot)
@@ -123,7 +141,7 @@ while [ $# -gt 0 ]; do
                 webroot="${2%/}"
                 shift
             else
-                badParam "$@"
+                badParam empty "$@"
             fi
             ;;
         -p|--seaf|--seafdir)
@@ -132,7 +150,7 @@ while [ $# -gt 0 ]; do
                 seafDir="${2%/}"
                 shift
             else
-                badParam "$@"
+                badParam empty "$@"
             fi
             ;;
         -d|--data|--datadir|--seafdata)
@@ -141,7 +159,7 @@ while [ $# -gt 0 ]; do
                 seafData="${2%/}"
                 shift
             else
-                badParam "$@"
+                badParam empty "$@"
             fi
             ;;
         -o|--offline)
@@ -154,7 +172,7 @@ while [ $# -gt 0 ]; do
                 seafUser="${2%/}"
                 shift
             else
-                badParam "$@"
+                badParam empty "$@"
             fi
             ;;
         *)