1VGDB(1)                         Release 3.15.0                         VGDB(1)
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NAME

6       vgdb - intermediary between Valgrind and GDB or a shell
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SYNOPSIS

9       vgdb [options]
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DESCRIPTION

12       vgdb ("Valgrind to GDB") is used as an intermediary between Valgrind
13       and GDB or a shell. It has two usage modes:
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15        1. As a standalone utility, it is used from a shell command line to
16           send monitor commands to a process running under Valgrind. For this
17           usage, the vgdb OPTION(s) must be followed by the monitor command
18           to send. To send more than one command, separate them with the -c
19           option.
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21        2. In combination with GDB "target remote |" command, it is used as
22           the relay application between GDB and the Valgrind gdbserver. For
23           this usage, only OPTION(s) can be given, but no COMMAND can be
24           given.
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OPTIONS

27       --pid=<number>
28           Specifies the PID of the process to which vgdb must connect to.
29           This option is useful in case more than one Valgrind gdbserver can
30           be connected to. If the --pid argument is not given and multiple
31           Valgrind gdbserver processes are running, vgdb will report the list
32           of such processes and then exit.
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34       --vgdb-prefix
35           Must be given to both Valgrind and vgdb if you want to change the
36           default prefix for the FIFOs (named pipes) used for communication
37           between the Valgrind gdbserver and vgdb.
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39       --wait=<number>
40           Instructs vgdb to search for available Valgrind gdbservers for the
41           specified number of seconds. This makes it possible start a vgdb
42           process before starting the Valgrind gdbserver with which you
43           intend the vgdb to communicate. This option is useful when used in
44           conjunction with a --vgdb-prefix that is unique to the process you
45           want to wait for. Also, if you use the --wait argument in the GDB
46           "target remote" command, you must set the GDB remotetimeout to a
47           value bigger than the --wait argument value. See option
48           --max-invoke-ms (just below) for an example of setting the
49           remotetimeout value.
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51       --max-invoke-ms=<number>
52           Gives the number of milliseconds after which vgdb will force the
53           invocation of gdbserver embedded in Valgrind. The default value is
54           100 milliseconds. A value of 0 disables forced invocation. The
55           forced invocation is used when vgdb is connected to a Valgrind
56           gdbserver, and the Valgrind process has all its threads blocked in
57           a system call.
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59           If you specify a large value, you might need to increase the GDB
60           "remotetimeout" value from its default value of 2 seconds. You
61           should ensure that the timeout (in seconds) is bigger than the
62           --max-invoke-ms value. For example, for --max-invoke-ms=5000, the
63           following GDB command is suitable:
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65                   (gdb) set remotetimeout 6
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69       --cmd-time-out=<number>
70           Instructs a standalone vgdb to exit if the Valgrind gdbserver it is
71           connected to does not process a command in the specified number of
72           seconds. The default value is to never time out.
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74       --port=<portnr>
75           Instructs vgdb to use tcp/ip and listen for GDB on the specified
76           port nr rather than to use a pipe to communicate with GDB. Using
77           tcp/ip allows to have GDB running on one computer and debugging a
78           Valgrind process running on another target computer. Example:
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80               # On the target computer, start your program under valgrind using
81               valgrind --vgdb-error=0 prog
82               # and then in another shell, run:
83               vgdb --port=1234
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85           On the computer which hosts GDB, execute the command:
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87               gdb prog
88               (gdb) target remote targetip:1234
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90           where targetip is the ip address or hostname of the target
91           computer.
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93       -c
94           To give more than one command to a standalone vgdb, separate the
95           commands by an option -c. Example:
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97               vgdb v.set log_output -c leak_check any
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99       -l
100           Instructs a standalone vgdb to report the list of the Valgrind
101           gdbserver processes running and then exit.
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103       -D
104           Instructs a standalone vgdb to show the state of the shared memory
105           used by the Valgrind gdbserver. vgdb will exit after having shown
106           the Valgrind gdbserver shared memory state.
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108       -d
109           Instructs vgdb to produce debugging output. Give multiple -d args
110           to increase the verbosity. When giving -d to a relay vgdb, you
111           better redirect the standard error (stderr) of vgdb to a file to
112           avoid interaction between GDB and vgdb debugging output.
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SEE ALSO

115       valgrind(1), $INSTALL/share/doc/valgrind/html/index.html or
116       http://www.valgrind.org/docs/manual/index.html, Debugging your program
117       using Valgrind's gdbserver and GDB[1] vgdb[2], Valgrind monitor
118       commands[3].
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AUTHOR

121       Philippe Waroquiers.
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NOTES

124        1. Debugging your program using Valgrind's gdbserver and GDB
125           http://www.valgrind.org/docs/manual/manual-core-adv.html#manual-core-adv.gdbserver
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127        2. vgdb
128           http://www.valgrind.org/docs/manual/manual-core-adv.html#manual-core-adv.vgdb
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130        3. Valgrind monitor commands
131           http://www.valgrind.org/docs/manual/manual-core-adv.html#manual-core-adv.valgrind-monitor-commands
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135Release 3.15.0                    04/13/2019                           VGDB(1)