getenv always return NULL in GDB/DDD

Simon Marchi simon.marchi@polymtl.ca
Fri Oct 26 14:21:00 GMT 2018


On 2018-10-26 05:35, Luo, Ginger wrote:
> Hello, GDB experts
> 
> 
> I try to call getenv in my C code, this can return correct env string
> in terminal, while it returns NULL in GDB/DDD.
> 
> 
> #include <stdlib.h>
> 
> #include <string.h>
> 
> #include <stdio.h>
> 
> void main() {
>   char * a = getenv("ANCHOR"); // ANCHOR exists in the terminal
>   if (strlen(a)>0)
>     printf("%s\n", a);
> }
> 
> 
> The GDB/DDD is started from the same terminal. Even I "show
> environment", this env exists.
> 
> Anyone any idea?
> 
> OS/Tools version info: RHEL Linux hostname1 2.6.32-754.3.5.el6.x86_64
> #1 SMP Thu Aug 9 11:56:22 EDT 2018 x86_64 GNU/Linux
> 
> GNU gdb (GDB) 7.12
> 
> gcc (GCC) 6.3.0
> SHELL is tcsh, DDD/GDB is using default settings.
> 
> Let me know if you need any further info.

I don't see off-hand why this would happen.  One thing to try would be 
"set startup-with-shell off".  If, for some reason, your shell (through 
which the debugged program is ran) messes up with the environment, this 
would bypass it entirely.

Otherwise, as usual, I would recommend trying the latest version of GDB. 
  I don't have anything specific in mind that changed recently, but it's 
good to try.

Simon



More information about the Gdb mailing list