what is the "-ex" command option?

what is the "-ex" command option?

[Smith John]

hi:
    when debugging using gdb , what  is  the   use  of   "-ex"  command option?


thanks!

Re: what is the "-ex" command option?

[Mike Frysinger]

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On Saturday 11 August 2012 03:33:26 Smith John wrote:
>     when debugging using gdb , what  is  the   use  of   "-ex"  command
> option?

$ gdb --help | grep -e--eval-command -A 3
  --eval-command=COMMAND, -ex
                     Execute a single GDB command.
                     May be used multiple times and in conjunction
                     with --command.

$ echo 'main(){}' | gcc -x c - -g -o a.out

$ gdb -ex 'break main' -ex run ./a.out
Reading symbols from /home/vapier/a.out...done.
Breakpoint 1 at 0x4004c8: file <stdin>, line 1.
Starting program: /home/vapier/a.out 

Breakpoint 1, main () at <stdin>:1
1       <stdin>: No such file or directory.
(gdb) 
-mike

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Re: what is the "-ex" command option?

[Eli Zaretskii]

> From: Mike Frysinger <vapier@gentoo.org>
> Date: Sat, 11 Aug 2012 11:59:15 -0400
> Cc: Smith John <horserivers@gmail.com>
> 
> $ gdb --help | grep -e--eval-command -A 3
>   --eval-command=COMMAND, -ex
>                      Execute a single GDB command.
>                      May be used multiple times and in conjunction
>                      with --command.

Btw, the place we show "-ex" on the screen is unfortunate, as it is
very hard to find it at first glance.  See how it is obscured by text
above and below it:

  --cd=DIR           Change current directory to DIR.
  --command=FILE, -x Execute GDB commands from FILE.
  --eval-command=COMMAND, -ex
                     Execute a single GDB command.
                     May be used multiple times and in conjunction

It would be much better if we reformat the output like this:

  --cd=DIR           Change current directory to DIR.
  --command=FILE, -x Execute GDB commands from FILE.
  --eval-command=COMMAND,
                 -ex Execute a single GDB command.
                     May be used multiple times and in conjunction