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VGDB(1) vgdb VGDB(1) NAME vgdb - intermediary between Valgrind and GDB or a shell SYNOPSIS vgdb [options] DESCRIPTION vgdb ("Valgrind to GDB") is used as an intermediary between Valgrind and GDB or a shell. It has three usage modes: 1. As a standalone utility, it is used from a shell command line to send monitor commands to a process running under Valgrind. For this usage, the vgdb OPTION(s) must be followed by the monitor command to send. To send more than one command, separate them with the -c option. 2. In combination with GDB "target remote |" command, it is used as the relay application between GDB and the Valgrind gdbserver. For this us- age, only OPTION(s) can be given, but no COMMAND can be given. 3. In the --multi mode, vgdb uses the extended remote protocol to communi- cate with GDB. This allows you to view output from both valgrind and GDB in the GDB session. This is accomplished via the "target ex- tended-remote | vgdb --multi". In this mode you no longer need to start valgrind yourself. vgdb will start up valgrind when gdb tells it to run a new program. For this usage, the vgdb OPTIONS(s) can also include --valgrind and --vargs to describe how valgrind should be started. OPTIONS --pid=<number> Specifies the PID of the process to which vgdb must connect to. This option is useful in case more than one Valgrind gdbserver can be con- nected to. If the --pid argument is not given and multiple Valgrind gdbserver processes are running, vgdb will report the list of such processes and then exit. --vgdb-prefix Must be given to both Valgrind and vgdb if you want to change the de- fault prefix for the FIFOs (named pipes) used for communication between the Valgrind gdbserver and vgdb. --wait=<number> Instructs vgdb to search for available Valgrind gdbservers for the specified number of seconds. This makes it possible start a vgdb process before starting the Valgrind gdbserver with which you intend the vgdb to communicate. This option is useful when used in conjunction with a --vgdb-prefix that is unique to the process you want to wait for. Also, if you use the --wait argument in the GDB "target remote" command, you must set the GDB remotetimeout to a value bigger than the --wait argument value. See option --max-invoke-ms (just below) for an example of setting the remotetimeout value. --max-invoke-ms=<number> Gives the number of milliseconds after which vgdb will force the invo- cation of gdbserver embedded in Valgrind. The default value is 100 mil- liseconds. A value of 0 disables forced invocation. The forced invoca- tion is used when vgdb is connected to a Valgrind gdbserver, and the Valgrind process has all its threads blocked in a system call. If you specify a large value, you might need to increase the GDB "re- motetimeout" value from its default value of 2 seconds. You should en- sure that the timeout (in seconds) is bigger than the --max-invoke-ms value. For example, for --max-invoke-ms=5000, the following GDB command is suitable: (gdb) set remotetimeout 6 --cmd-time-out=<number> Instructs a standalone vgdb to exit if the Valgrind gdbserver it is connected to does not process a command in the specified number of sec- onds. The default value is to never time out. --port=<portnr> Instructs vgdb to use tcp/ip and listen for GDB on the specified port nr rather than to use a pipe to communicate with GDB. Using tcp/ip al- lows to have GDB running on one computer and debugging a Valgrind process running on another target computer. Example: # On the target computer, start your program under valgrind using valgrind --vgdb-error=0 prog # and then in another shell, run: vgdb --port=1234 On the computer which hosts GDB, execute the command: gdb prog (gdb) target remote targetip:1234 where targetip is the ip address or hostname of the target computer. --vgdb-multi Makes vgdb start in extended-remote mode and to wait for gdb to tell us what to run. --valgrind The path to valgrind to use, in extended-remote mode. If not specified, the system valgrind will be launched. --vargs Options to run valgrind with, in extended-remote mode. For example -q. Everything following --vargs will be provided as arguments to valgrind as is. -c To give more than one command to a standalone vgdb, separate the com- mands by an option -c. Example: vgdb v.set log_output -c leak_check any -l Instructs a standalone vgdb to report the list of the Valgrind gdb- server processes running and then exit. -T Instructs vgdb to add timestamps to vgdb information messages. -D Instructs a standalone vgdb to show the state of the shared memory used by the Valgrind gdbserver. vgdb will exit after having shown the Val- grind gdbserver shared memory state. -d Instructs vgdb to produce debugging output. Give multiple -d args to increase the verbosity. When giving -d to a relay vgdb, you better redirect the standard error (stderr) of vgdb to a file to avoid inter- action between GDB and vgdb debugging output. SEE ALSO valgrind(1), $INSTALL/share/doc/valgrind/html/index.html or http://www.val- grind.org/docs/manual/index.html, Debugging your program using Valgrind's gdbserver and GDB[1] vgdb[2], Val- grind monitor commands[3]. AUTHOR Philippe Waroquiers. NOTES 1. Debugging your program using Valgrind's gdbserver and GDB http://www.valgrind.org/docs/manual/manual-core-adv.html#manual-core-adv.gdbserver 2. vgdb http://www.valgrind.org/docs/manual/manual-core-adv.html#manual-core-adv.vgdb 3. Valgrind monitor commands http://www.valgrind.org/docs/manual/manual-core-adv.html#manual-core-adv.valgrind-monitor-commands Release 3.26.0.GIT 08/01/2026 VGDB(1)
NAME | SYNOPSIS | DESCRIPTION | OPTIONS | SEE ALSO | AUTHOR | NOTES
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