Minor refactoring

1 files changed, 9 insertions, 5 deletions

diff --git a/src/main/java/com/it_jaros/jscanner/CliParser.java b/src/main/java/com/it_jaros/jscanner/CliParser.java
index 0d6fb7b..707abb5 100644
--- a/src/main/java/com/it_jaros/jscanner/CliParser.java
+++ b/src/main/java/com/it_jaros/jscanner/CliParser.java
@@ -44,7 +44,7 @@ public class CliParser {
                     usageAndExit(0);
                     break;
                 case "--input", "-i":
-                    hostsFile = requireValue(args, ++i, currentArg);
+                    hostsFile = getArgument(args, ++i, currentArg);
                     break;
                 case "--maxHostsLimit", "-m":
                     maxHostsLimit = parseIntOption(args, ++i, currentArg);
@@ -53,7 +53,7 @@ public class CliParser {
                     maxWorkersPerHost = parseIntOption(args, ++i, currentArg);
                     break;
                 case "--ports", "-p":
-                    ports = requireValue(args, ++i, currentArg);
+                    ports = getArgument(args, ++i, currentArg);
                     break;
                 case "--quiet", "-q":
                     quiet = true;
@@ -72,10 +72,14 @@ public class CliParser {
             }
         }
 
+        if (hostsArgv.isEmpty() && hostsFile == null) {
+           throw new IllegalStateException("No input provided. Check with --help for available options.");
+        }
+
         return new ScanOptions(hostsArgv.stream().toList(), socketLimit, delayInMillis, timeoutInMillis, maxWorkersPerHost, maxHostsLimit, ports, showFilteredPorts, disableOnlineCheck, hostsFile, quiet, bannerRecognition);
     }
 
-    private String requireValue(String[] args, int index, String option) {
+    private String getArgument(String[] args, int index, String option) {
         if (index >= args.length) {
             throw new IllegalArgumentException(String.format("Missing argument for option %s", option));
         }
@@ -83,7 +87,7 @@ public class CliParser {
     }
 
     private int parseIntOption(String[] args, int index, String option) {
-        String value = requireValue(args, index, option);
+        String value = getArgument(args, index, option);
         try {
             return Integer.parseInt(value);
         } catch (NumberFormatException e) {
@@ -103,7 +107,7 @@ public class CliParser {
                     --bannerRecognition, -b:\tEnable banner recognition to find out which service is running behind port (Default :%b)
                     --delay, -d:\t\tWaiting period in millis for connection attempts for a host (Default: %d)
                     --disableOnlineCheck, -do:\tDon't check if Host is reachable (Default: %b)
-                    --input, -i:\t\tRead file to get host targets to scan (Default: null)
+                    --input, -i:\t\tRead file to get host targets to scan. If set to "-" than Stdin is read (Default: null)
                     --maxHostsLimit, -m:\tMax number of hosts that are scanned at the same time (Default: %d)
                     --maxWorkersPerHost, -mh:\tVirtual Worker Threads run per Host. Higher doesn't mean necessarily faster. But the more you use the more RAM is required (Default: %d)
                     --ports, -p:\t\tDefine ports to be scanned (Default: %s)