@value{GDBP} @var{program} @var{core}
@end smallexample
-You can, instead, specify a process ID as a second argument, if you want
-to debug a running process:
+You can, instead, specify a process ID as a second argument or use option
+@code{-p}, if you want to debug a running process:
@smallexample
@value{GDBP} @var{program} 1234
+@value{GDBP} -p 1234
@end smallexample
@noindent
-would attach @value{GDBN} to process @code{1234} (unless you also have a file
-named @file{1234}; @value{GDBN} does check for a core file first).
+would attach @value{GDBN} to process @code{1234}. With option @option{-p} you
+can omit the @var{program} filename.
Taking advantage of the second command-line argument requires a fairly
complete operating system; when you use @value{GDBN} as a remote
@menu
* Command Syntax:: How to give commands to @value{GDBN}
+* Command Settings:: How to change default behavior of commands
* Completion:: Command completion
* Command Options:: Command options
* Help:: How to ask @value{GDBN} for help
then fetches the next line relative to the current line from the history
for editing.
+
+@node Command Settings
+@section Command Settings
+@cindex default behavior of commands, changing
+@cindex default settings, changing
+
+Many commands change their behavior according to command-specific
+variables or settings. These settings can be changed with the
+@code{set} subcommands. For example, the @code{print} command
+(@pxref{Data, ,Examining Data}) prints arrays differently depending on
+settings changeable with the commands @code{set print elements
+NUMBER-OF-ELEMENTS} and @code{set print array-indexes}, among others.
+
+You can change these settings to your preference in the gdbinit files
+loaded at @value{GDBN} startup. @xref{Startup}.
+
+The settings can also be changed interactively during the debugging
+session. For example, to change the limit of array elements to print,
+you can do the following:
+@smallexample
+(@value{GDBN}) set print elements 10
+(@value{GDBN}) print some_array
+$1 = @{0, 10, 20, 30, 40, 50, 60, 70, 80, 90...@}
+@end smallexample
+
+The above @code{set print elements 10} command changes the number of
+elements to print from the default of 200 to 10. If you only intend
+this limit of 10 to be used for printing @code{some_array}, then you
+must restore the limit back to 200, with @code{set print elements
+200}.
+
+Some commands allow overriding settings with command options. For
+example, the @code{print} command supports a number of options that
+allow overriding relevant global print settings as set by @code{set
+print} subcommands. @xref{print options}. The example above could be
+rewritten as:
+@smallexample
+(@value{GDBN}) print -elements 10 -- some_array
+$1 = @{0, 10, 20, 30, 40, 50, 60, 70, 80, 90...@}
+@end smallexample
+
+Alternatively, you can use the @code{with} command to change a setting
+temporarily, for the duration of a command invocation.
+
+@table @code
+@kindex with command
+@kindex w @r{(@code{with})}
+@cindex settings
+@cindex temporarily change settings
+@item with @var{setting} [@var{value}] [-- @var{command}]
+@itemx w @var{setting} [@var{value}] [-- @var{command}]
+Temporarily set @var{setting} to @var{value} for the duration of
+@var{command}.
+
+@var{setting} is any setting you can change with the @code{set}
+subcommands. @var{value} is the value to assign to @code{setting}
+while running @code{command}.
+
+If no @var{command} is provided, the last command executed is
+repeated.
+
+If a @var{command} is provided, it must be preceded by a double dash
+(@code{--}) separator. This is required because some settings accept
+free-form arguments, such as expressions or filenames.
+
+For example, the command
+@smallexample
+(@value{GDBN}) with print array on -- print some_array
+@end smallexample
+@noindent
+is equivalent to the following 3 commands:
+@smallexample
+(@value{GDBN}) set print array on
+(@value{GDBN}) print some_array
+(@value{GDBN}) set print array off
+@end smallexample
+
+The @code{with} command is particularly useful when you want to
+override a setting while running user-defined commands, or commands
+defined in Python or Guile. @xref{Extending GDB,, Extending GDB}.
+
+@smallexample
+(@value{GDBN}) with print pretty on -- my_complex_command
+@end smallexample
+
+To change several settings for the same command, you can nest
+@code{with} commands. For example, @code{with language ada -- with
+print elements 10} temporarily changes the language to Ada and sets a
+limit of 10 elements to print for arrays and strings.
+
+@end table
+
@node Completion
@section Command Completion
of such variables.
@kindex info types
-@item info types @var{regexp}
-@itemx info types
+@item info types [-q] [@var{regexp}]
Print a brief description of all types whose names match the regular
expression @var{regexp} (or all types in your program, if you supply
no argument). Each complete typename is matched as though it were a
@code{whatis}, it does not print a detailed description; second, it
lists all source files and line numbers where a type is defined.
+The output from @samp{into types} is proceeded with a header line
+describing what types are being listed. The optional flag @samp{-q},
+which stands for @samp{quiet}, disables printing this header
+information.
+
@kindex info type-printers
@item info type-printers
Versions of @value{GDBN} that ship with Python scripting enabled may
@smallexample
-catch-throw -r exception_type
-^done,bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y",
- addr="0x00000000004006c0",what="exception throw",
- catch-type="throw",thread-groups=["i1"],
+^done,bkpt=@{number="1",type="catchpoint",disp="keep",enabled="y",
+ what="exception throw",catch-type="throw",
+ thread-groups=["i1"],
regexp="exception_type",times="0"@}
(gdb)
-exec-run
@smallexample
-catch-rethrow -r exception_type
-^done,bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y",
- addr="0x00000000004006c0",what="exception rethrow",
- catch-type="rethrow",thread-groups=["i1"],
+^done,bkpt=@{number="1",type="catchpoint",disp="keep",enabled="y",
+ what="exception rethrow",catch-type="rethrow",
+ thread-groups=["i1"],
regexp="exception_type",times="0"@}
(gdb)
-exec-run
@smallexample
-catch-catch -r exception_type
-^done,bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y",
- addr="0x00000000004006c0",what="exception catch",
- catch-type="catch",thread-groups=["i1"],
+^done,bkpt=@{number="1",type="catchpoint",disp="keep",enabled="y",
+ what="exception catch",catch-type="catch",
+ thread-groups=["i1"],
regexp="exception_type",times="0"@}
(gdb)
-exec-run
subcommands. This is used by the testsuite to validate completion
support in the command options framework.
-@kindex maint test-settings
-@item maint test-settings set @var{kind}
-@itemx maint test-settings show @var{kind}
+@kindex maint set test-settings
+@kindex maint show test-settings
+@item maint set test-settings @var{kind}
+@itemx maint show test-settings @var{kind}
These are representative commands for each @var{kind} of setting type
@value{GDBN} supports. They are used by the testsuite for exercising
the settings infrastructure.
+
+@kindex maint with
+@item maint with @var{setting} [@var{value}] [-- @var{command}]
+Like the @code{with} command, but works with @code{maintenance set}
+variables. This is used by the testsuite to exercise the @code{with}
+command's infrastructure.
+
@end table
The following command is useful for non-interactive invocations of
gdb program core
@end smallexample
-You can, instead, specify a process ID as a second argument, if you want
-to debug a running process:
+You can, instead, specify a process ID as a second argument or use option
+@code{-p}, if you want to debug a running process:
@smallexample
gdb program 1234
@end smallexample
@noindent
-would attach @value{GDBN} to process @code{1234} (unless you also have a file
-named @file{1234}; @value{GDBN} does check for a core file first).
-With option @option{-p} you can omit the @var{program} filename.
+would attach @value{GDBN} to process @code{1234}. With option @option{-p} you
+can omit the @var{program} filename.
Here are some of the most frequently needed @value{GDBN} commands:
projects / deliverable / binutils-gdb.git / blobdiff