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spring-shell-docs/modules/ROOT/pages/customization/logging.adoc

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+[[using-shell-customization-logging]]
+= Logging
+
+On default a _Spring Boot_ application will log messages into a console which
+at minimum is annoying and may also mix output from a shell commands.
+Fortunately there is a simple way to instruct logging changes via boot properties.
+
+Completely silence console logging by defining its pattern as an empty value.
+
+[source, yaml]
+----
+logging:
+  pattern:
+    console:
+----
+
+If you need log from a shell then write those into a file.
+
+[source, yaml]
+----
+logging:
+  file:
+    name: shell.log
+----
+
+If you need different log levels.
+
+[source, yaml]
+----
+logging:
+  level:
+    org:
+      springframework:
+        shell: debug
+----
+
+Passing contiguration properties as command line options is not supported but
+you can use any other ways supported by boot, for example.
+
+[source, bash]
+----
+$ java -Dlogging.level.root=debug -jar demo.jar
+$ LOGGING_LEVEL_ROOT=debug java -jar demo.jar
+----
+
+NOTE: In a GraalVM image settings are locked during compilation which means
+      you can't change log levels at runtime.