programs you run. When debugging, it can be useful to try running your program with a modified environment without having to start GDB over again.

show envvar

List all the environment variables used by GDB.

show paths

Display the list of search paths for executables

 

(the PATH environment variable).

show environment [varname]

Print the value of environment variable varname

 

to be given to your program when it starts. If you

 

do not supply varname, print the names and

 

values of all environment variables to be given

 

to your program. You can abbreviate

 

environment as env.

set environment varname

Set environment variable varname to value.

[=value]

The value changes for your program only, not

 

for GDB itself. The value may be any string; the

 

values of environment variables are just strings,

 

and any interpretation is supplied by your

 

program itself. The value parameter is optional;

 

if it is eliminated, the variable is set to a null

 

value.

 

For example, this command:

 

set env USER = foo

 

tells the debugged program, when subsequently

 

run, that its user is named 'foo'. (The spaces

 

around '=' are used for clarity here; they are not

 

actually required.)

unset environment varname

Remove variable varname from the environment

 

to be passed to your program. This is different

 

from 'set env varname ='; unset

 

environment removes the variable from the

 

environment, rather than assigning it an empty

 

value.

path directory

Add directory to the front of the PATH

 

environment variable (the search path for

 

executables), for both GDB and your program.

 

You may specify several directory names,

 

separated by whitespace or by a

 

system-dependent separator character (`:' on

 

Unix, `;' on MS-DOS and MS-Windows). If

 

directory is already in the path, it is moved

 

to the front, so it is searched sooner.

42 Running Programs Under GDB