Add --strict so failures report a non-zero exit code

Every error path did printStackTrace() then System.exit(0), making a
failed run indistinguishable from a successful one to any caller checking
$?. pipekit works around this by grepping stdout for stack-trace text
(_detect_silent_failure); 112 /opt/sync scripts run under `set -e` and
cannot detect a jrunner failure at all.

All 14 error exits now route through die(), which honours --strict.
Opt-in rather than default: flipping it unconditionally would change the
behaviour of those 112 scripts at once. --strict is pre-scanned from argv
so it applies to failures during argument parsing too.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

jrunner/src/main/java/jrunner/jrunner.java

@@ -70,6 +70,7 @@ public class jrunner {
         msg = msg + nl + "-b         bulk copy into destination (SQL Server dest only)";
         msg = msg + nl + "-f         output format (csv, tsv, table, json) - default: csv";
         msg = msg + nl + "--passfile path to the connection alias file - default: ~/.jrunnerpass";
+        msg = msg + nl + "--strict   exit 1 on failure (default exits 0, for legacy callers)";
         msg = msg + nl + "--help     info";
         msg = msg + nl + "";
         msg = msg + nl + "Prefer -sc/-dc aliases over -scp/-dcp: a password given on the";
@@ -83,6 +84,12 @@ public class jrunner {
 
         //---------------------------------------parse args into variables-------------------------------------------------
 
+        // Pre-scan: -sq can fail while the loop is still running, and it must
+        // honour --strict regardless of where the flag sits in argv.
+        for (String a : args) {
+            if (a.equals("--strict")) strictExit = true;
+        }
+
         for (int i = 0; i < args.length; i = i +1 ){
             switch (args[i]) {
                 //source connection alias
@@ -126,7 +133,7 @@ public class jrunner {
                     catch (Exception e) {
                         //System.out.println(nl + "error reasing source sql file: " + printStackTrace());
                         e.printStackTrace();
-                        System.exit(0);
+                        die();
                         return;
                     }
                     break;
@@ -150,6 +157,9 @@ public class jrunner {
                 case "--passfile":
                     passFilePath = args[i+1];
                     break;
+                //exit non-zero on failure (handled in the pre-scan above)
+                case "--strict":
+                    break;
                 case "-v":
                     System.out.println(msg);
                     return;
@@ -223,7 +233,7 @@ public class jrunner {
             Class.forName("com.ibm.as400.access.AS400JDBCDriver");
         } catch (ClassNotFoundException cnf) {
             System.out.println("The AS400 JDBC driver did not load");
-            System.exit(0);
+            die();
         }
 
         //-------------------------------------------establish connections-------------------------------------------------
@@ -245,7 +255,7 @@ public class jrunner {
         } catch (SQLException e) {
             System.out.println("issue connecting to source:");
             e.printStackTrace();
-            System.exit(0);
+            die();
         }
         if (!queryMode) {
             System.out.println(" ✅ source database");
@@ -257,7 +267,7 @@ public class jrunner {
             } catch (SQLException e) {
                 System.out.println("issue connecting to destination:");
                 e.printStackTrace();
-                System.exit(0);
+                die();
             }
             System.out.println(" ✅ destination database");
         }
@@ -276,7 +286,7 @@ public class jrunner {
         } catch (SQLException e) {
             System.out.println("issue retrieving rows from source:");
             e.printStackTrace();
-            System.exit(0);
+            die();
         } 
 
         //---------------------------------------build meta---------------------------------------------------------------
@@ -290,7 +300,7 @@ public class jrunner {
             dtn  = new String[cols + 1];
         } catch (SQLException e) {
             e.printStackTrace();
-            System.exit(0);
+            die();
         }
         try {
             for (int i = 1; i <= cols; i++){
@@ -301,7 +311,7 @@ public class jrunner {
             }
         } catch (SQLException e) {
             e.printStackTrace();
-            System.exit(0);
+            die();
         }
         //-------------------------clear the target table if requeted----------------------------------------------------
         if (!queryMode && clear) {
@@ -314,7 +324,7 @@ public class jrunner {
             } catch (SQLException e) {
                 e.printStackTrace();
                 System.out.println(sql);
-                System.exit(0);
+                die();
             }
         }
         if (queryMode) {
@@ -323,7 +333,7 @@ public class jrunner {
                 outputQueryResults(rs, cols, dtn, outputFormat);
             } catch (SQLException e) {
                 e.printStackTrace();
-                System.exit(0);
+                die();
             }
         } else if (bulk && dcu.toLowerCase().startsWith("jdbc:sqlserver:")) {
             //-------------------------------bulk copy (SQL Server dest)-------------------------------------------------
@@ -347,7 +357,7 @@ public class jrunner {
                 System.out.print("\r" + src.rowsWritten());
             } catch (Exception e) {
                 e.printStackTrace();
-                System.exit(0);
+                die();
             }
         } else if (bulk && dcu.toLowerCase().startsWith("jdbc:postgresql:")) {
             //-------------------------------bulk copy (COPY, Postgres dest)--------------------------------------------
@@ -389,7 +399,7 @@ public class jrunner {
                 System.out.print("\r" + rows);
             } catch (Exception e) {
                 e.printStackTrace();
-                System.exit(0);
+                die();
             }
         } else {
             System.out.println("------------row count-------------------------------------");
@@ -523,7 +533,7 @@ public class jrunner {
                     } catch (SQLException e) {
                         e.printStackTrace();
                         System.out.println(sql);
-                        System.exit(0);
+                        die();
                     }
                     sql = "";
                 }
@@ -538,12 +548,12 @@ public class jrunner {
                 } catch (SQLException e) {
                     e.printStackTrace();
                     System.out.println(sql);
-                    System.exit(0);
+                    die();
                 }
             }
             } catch (SQLException e) {
                 e.printStackTrace();
-                System.exit(0);
+                die();
             }
         }
         //System.out.println(sql);
@@ -767,6 +777,17 @@ public class jrunner {
         return value;
     }
 
+    // Historically every error path did printStackTrace() then System.exit(0),
+    // so a failed run was indistinguishable from a successful one to any
+    // caller checking $?. 112 /opt/sync scripts run under `set -e` against
+    // that behaviour, so flipping it unconditionally would change them all at
+    // once; --strict makes the correct exit code opt-in until they're audited.
+    private static boolean strictExit = false;
+
+    private static void die() {
+        System.exit(strictExit ? 1 : 0);
+    }
+
     private static String escapeTSV(String value) {
         return value.replaceAll("\t", " ").replaceAll("\n", " ").replaceAll("\r", " ");
     }