Shell Commands (Debugging with GDB)
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2.3 Shell Commands
If you need to execute occasional shell commands during your debugging session, there is no need to leave or suspend GDB; you can just use the shell
command.
shell command-string
!command-string
Invoke a standard shell to execute command-string
. Note that no space is needed between !
and command-string
. On GNU and Unix systems, the environment variable SHELL
, if it exists, determines which shell to run. Otherwise GDB uses the default shell (/bin/sh
on GNU and Unix systems, cmd.exe
on MS-Windows, COMMAND.COM
on MS-DOS, etc.).
The utility make
is often needed in development environments. You do not have to use the shell
command for this purpose in GDB:
make make-args
Execute the make
program with the specified arguments. This is equivalent to ‘shell make make-args
’.
pipe [command] | shell_command
| [command] | shell_command
pipe -d delim command delim shell_command
| -d delim command delim shell_command
Executes command
and sends its output to shell_command
. Note that no space is needed around |
. If no command
is provided, the last command executed is repeated.
In case the command
contains a |
, the option -d delim
can be used to specify an alternate delimiter string delim
that separates the command
from the shell_command
.
Example:
(gdb) p var $1 = { black = 144, red = 233, green = 377, blue = 610, white = 987 }
(gdb) pipe p var|wc 7 19 80 (gdb) |p var|wc -l 7
(gdb) p /x var $4 = { black = 0x90, red = 0xe9, green = 0x179, blue = 0x262, white = 0x3db } (gdb) ||grep red red => 0xe9,
(gdb) | -d ! echo this contains a | char\n ! sed -e 's/|/PIPE/' this contains a PIPE char (gdb) | -d xxx echo this contains a | char!\n xxx sed -e 's/|/PIPE/' this contains a PIPE char! (gdb)
The convenience variables $_shell_exitcode
and $_shell_exitsignal
can be used to examine the exit status of the last shell command launched by shell
, make
, pipe
and |
. See Convenience Variables.
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