--- old/src/linux/doc/man/jdb.1 2018-11-26 19:42:59.706335860 +0100 +++ /dev/null 2018-10-10 08:50:32.889292854 +0200 @@ -1,267 +0,0 @@ -'\" t -.\" Copyright (c) 1995, 2013, Oracle and/or its affiliates. All rights reserved. -.\" DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. -.\" -.\" This code is free software; you can redistribute it and/or modify it -.\" under the terms of the GNU General Public License version 2 only, as -.\" published by the Free Software Foundation. -.\" -.\" This code is distributed in the hope that it will be useful, but WITHOUT -.\" ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or -.\" FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -.\" version 2 for more details (a copy is included in the LICENSE file that -.\" accompanied this code). -.\" -.\" You should have received a copy of the GNU General Public License version -.\" 2 along with this work; if not, write to the Free Software Foundation, -.\" Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. -.\" -.\" Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA -.\" or visit www.oracle.com if you need additional information or have any -.\" questions. -.\" -.\" Arch: generic -.\" Software: JDK 8 -.\" Date: 21 November 2013 -.\" SectDesc: Basic Tools -.\" Title: jdb.1 -.\" -.if n .pl 99999 -.TH jdb 1 "21 November 2013" "JDK 8" "Basic Tools" -.\" ----------------------------------------------------------------- -.\" * Define some portability stuff -.\" ----------------------------------------------------------------- -.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -.\" http://bugs.debian.org/507673 -.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html -.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -.ie \n(.g .ds Aq \(aq -.el .ds Aq ' -.\" ----------------------------------------------------------------- -.\" * set default formatting -.\" ----------------------------------------------------------------- -.\" disable hyphenation -.nh -.\" disable justification (adjust text to left margin only) -.ad l -.\" ----------------------------------------------------------------- -.\" * MAIN CONTENT STARTS HERE * -.\" ----------------------------------------------------------------- - -.SH NAME -jdb \- Finds and fixes bugs in Java platform programs\&. -.SH SYNOPSIS -.sp -.nf - -\fBjdb\fR [\fIoptions\fR] [\fIclassname\fR] [\fIarguments\fR] -.fi -.sp -.TP -\fIoptions\fR -Command-line options\&. See Options\&. -.TP -\fIclass\fRname -Name of the main class to debug\&. -.TP -\fIarguments\fR -Arguments passed to the \f3main()\fR method of the class\&. -.SH DESCRIPTION -The Java Debugger (JDB) is a simple command-line debugger for Java classes\&. The \f3jdb\fR command and its options call the JDB\&. The \f3jdb\fR command demonstrates the Java Platform Debugger Architecture (JDBA) and provides inspection and debugging of a local or remote Java Virtual Machine (JVM)\&. See Java Platform Debugger Architecture (JDBA) at http://docs\&.oracle\&.com/javase/8/docs/technotes/guides/jpda/index\&.html -.SS START\ A\ JDB\ SESSION -There are many ways to start a JDB session\&. The most frequently used way is to have JDB launch a new JVM with the main class of the application to be debugged\&. Do this by substituting the \f3jdb\fR command for the \f3java\fR command in the command line\&. For example, if your application\&'s main class is \f3MyClass\fR, then use the following command to debug it under JDB: -.sp -.nf -\f3jdb MyClass\fP -.fi -.nf -\f3\fP -.fi -.sp -When started this way, the \f3jdb\fR command calls a second JVM with the specified parameters, loads the specified class, and stops the JVM before executing that class\&'s first instruction\&. -.PP -Another way to use the \f3jdb\fR command is by attaching it to a JVM that is already running\&. Syntax for starting a JVM to which the \f3jdb\fR command attaches when the JVM is running is as follows\&. This loads in-process debugging libraries and specifies the kind of connection to be made\&. -.sp -.nf -\f3java \-agentlib:jdwp=transport=dt_socket,server=y,suspend=n MyClass\fP -.fi -.nf -\f3\fP -.fi -.sp -You can then attach the \f3jdb\fR command to the JVM with the following command: -.sp -.nf -\f3jdb \-attach 8000\fP -.fi -.nf -\f3\fP -.fi -.sp -The \f3MyClass\fR argument is not specified in the \f3jdb\fR command line in this case because the \f3jdb\fR command is connecting to an existing JVM instead of launching a new JVM\&. -.PP -There are many other ways to connect the debugger to a JVM, and all of them are supported by the \f3jdb\fR command\&. The Java Platform Debugger Architecture has additional documentation on these connection options\&. -.SS BASIC\ JDB\ COMMANDS -The following is a list of the basic \f3jdb\fR commands\&. The JDB supports other commands that you can list with the \f3-help\fR option\&. -.TP -help or ? -The \f3help\fR or \f3?\fR commands display the list of recognized commands with a brief description\&. -.TP -run -After you start JDB and set breakpoints, you can use the \f3run\fR command to execute the debugged application\&. The \f3run\fR command is available only when the \f3jdb\fR command starts the debugged application as opposed to attaching to an existing JVM\&. -.TP -cont -Continues execution of the debugged application after a breakpoint, exception, or step\&. -.TP -print -Displays Java objects and primitive values\&. For variables or fields of primitive types, the actual value is printed\&. For objects, a short description is printed\&. See the dump command to find out how to get more information about an object\&. - -\fINote:\fR To display local variables, the containing class must have been compiled with the \f3javac -g\fR option\&. - -The \f3print\fR command supports many simple Java expressions including those with method invocations, for example: -.sp -.nf -\f3print MyClass\&.myStaticField\fP -.fi -.nf -\f3print myObj\&.myInstanceField\fP -.fi -.nf -\f3print i + j + k (i, j, k are primities and either fields or local variables)\fP -.fi -.nf -\f3print myObj\&.myMethod() (if myMethod returns a non\-null)\fP -.fi -.nf -\f3print new java\&.lang\&.String("Hello")\&.length()\fP -.fi -.nf -\f3\fP -.fi -.sp - -.TP -dump -For primitive values, the \f3dump\fR command is identical to the \f3print\fR command\&. For objects, the \f3dump\fR command prints the current value of each field defined in the object\&. Static and instance fields are included\&. The \f3dump\fR command supports the same set of expressions as the \f3print\fR command\&. -.TP -threads -List the threads that are currently running\&. For each thread, its name and current status are printed and an index that can be used in other commands\&. In this example, the thread index is 4, the thread is an instance of \f3java\&.lang\&.Thread\fR, the thread name is \f3main\fR, and it is currently running\&. -.sp -.nf -\f34\&. (java\&.lang\&.Thread)0x1 main running\fP -.fi -.nf -\f3\fP -.fi -.sp - -.TP -thread -Select a thread to be the current thread\&. Many \f3jdb\fR commands are based on the setting of the current thread\&. The thread is specified with the thread index described in the threads command\&. -.TP -where -The \f3where\fR command with no arguments dumps the stack of the current thread\&. The \f3where\fR\f3all\fR command dumps the stack of all threads in the current thread group\&. The \f3where\fR\f3threadindex\fR command dumps the stack of the specified thread\&. - -If the current thread is suspended either through an event such as a breakpoint or through the \f3suspend\fR command, then local variables and fields can be displayed with the \f3print\fR and \f3dump\fR commands\&. The \f3up\fR and \f3down\fR commands select which stack frame is the current stack frame\&. -.SS BREAKPOINTS -Breakpoints can be set in JDB at line numbers or at the first instruction of a method, for example: -.TP 0.2i -\(bu -The command \f3stop at MyClass:22\fR sets a breakpoint at the first instruction for line 22 of the source file containing \f3MyClass\fR\&. -.TP 0.2i -\(bu -The command \f3stop in java\&.lang\&.String\&.length\fR sets a breakpoint at the beginning of the method \f3java\&.lang\&.String\&.length\fR\&. -.TP 0.2i -\(bu -The command \f3stop in MyClass\&.\fR uses \f3\fR to identify the static initialization code for \f3MyClass\fR\&. -.PP -When a method is overloaded, you must also specify its argument types so that the proper method can be selected for a breakpoint\&. For example, \f3MyClass\&.myMethod(int,java\&.lang\&.String)\fR or \f3MyClass\&.myMethod()\fR\&. -.PP -The \f3clear\fR command removes breakpoints using the following syntax: \f3clear MyClass:45\fR\&. Using the \f3clear\fR or \f3stop\fR command with no argument displays a list of all breakpoints currently set\&. The \f3cont\fR command continues execution\&. -.SS STEPPING -The \f3step\fR command advances execution to the next line whether it is in the current stack frame or a called method\&. The \f3next\fR command advances execution to the next line in the current stack frame\&. -.SS EXCEPTIONS -When an exception occurs for which there is not a \f3catch\fR statement anywhere in the throwing thread\&'s call stack, the JVM typically prints an exception trace and exits\&. When running under JDB, however, control returns to JDB at the offending throw\&. You can then use the \f3jdb\fR command to diagnose the cause of the exception\&. -.PP -Use the \f3catch\fR command to cause the debugged application to stop at other thrown exceptions, for example: \f3catch java\&.io\&.FileNotFoundException\fR or \f3catch\fR\f3mypackage\&.BigTroubleException\fR\&. Any exception that is an instance of the specified class or subclass stops the application at the point where it is thrown\&. -.PP -The \f3ignore\fR command negates the effect of an earlier \f3catch\fR command\&. The \f3ignore\fR command does not cause the debugged JVM to ignore specific exceptions, but only to ignore the debugger\&. -.SH OPTIONS -When you use the \f3jdb\fR command instead of the \f3java\fR command on the command line, the \f3jdb\fR command accepts many of the same options as the \f3java\fR command, including \f3-D\fR, \f3-classpath\fR, and \f3-X\fR options\&. The following list contains additional options that are accepted by the \f3jdb\fR command\&. -.PP -Other options are supported to provide alternate mechanisms for connecting the debugger to the JVM it is to debug\&. For additional documentation about these connection alternatives, see Java Platform Debugger Architecture (JPDA) at http://docs\&.oracle\&.com/javase/8/docs/technotes/guides/jpda/index\&.html -.TP --help -.br -Displays a help message\&. -.TP --sourcepath \fIdir1:dir2: \&. \&. \&.\fR -.br -Uses the specified path to search for source files in the specified path\&. If this option is not specified, then use the default path of dot (\&.)\&. -.TP --attach \fIaddress\fR -.br -Attaches the debugger to a running JVM with the default connection mechanism\&. -.TP --listen \fIaddress\fR -.br -Waits for a running JVM to connect to the specified address with a standard connector\&. -.TP --launch -.br -Starts the debugged application immediately upon startup of JDB\&. The \f3-launch\fR option removes the need for the \f3run\fR command\&. The debugged application is launched and then stopped just before the initial application class is loaded\&. At that point, you can set any necessary breakpoints and use the \f3cont\fR command to continue execution\&. -.TP --listconnectors -.br -List the connectors available in this JVM\&. -.TP --connect connector-name:\fIname1=value1\fR -.br -Connects to the target JVM with the named connector and listed argument values\&. -.TP --dbgtrace [\fIflags\fR] -.br -Prints information for debugging the \f3jdb\fR command\&. -.TP --tclient -.br -Runs the application in the Java HotSpot VM client\&. -.TP --tserver -.br -Runs the application in the Java HotSpot VM server\&. -.TP --J\fIoption\fR -.br -Passes \f3option\fR to the JVM, where option is one of the options described on the reference page for the Java application launcher\&. For example, \f3-J-Xms48m\fR sets the startup memory to 48 MB\&. See java(1)\&. -.SH OPTIONS\ FORWARDED\ TO\ THE\ DEBUGGER\ PROCESS -.TP --v -verbose[:\fIclass\fR|gc|jni] -.br -Turns on verbose mode\&. -.TP --D\fIname\fR=\fIvalue\fR -.br -Sets a system property\&. -.TP --classpath \fIdir\fR -.br -Lists directories separated by colons in which to look for classes\&. -.TP --X\fIoption\fR -.br -Nonstandard target JVM option\&. -.SH SEE\ ALSO -.TP 0.2i -\(bu -javac(1) -.TP 0.2i -\(bu -java(1) -.TP 0.2i -\(bu -javap(1) -.RE -.br -'pl 8.5i -'bp