I'm writing up some gdb functions in my gdbinit that can help me connect to various remote targets, but I haven't been able to use the variables correctly. The variables don't seem to get expanded/ defined correctly, how do I do this correctly?
set variable HOST1="127.0.0.0"
set variable PORT1="1234"
define connect_host1
target remote $HOST1:$PORT1
end
Related
I have a pre-request script that increments an enviroment variable to generate different ids each time a request is generated. Also, I have a runner that calls this request multiple times:
However, I’ve noticed that during the runner the environment variable is not updated, at least in the environment’s tab:
But I monitor the variable in the console log and it is incrementing correctly:
My problem is that if I prematurely stop the runner before all the requests end, the environment variable didn’t register all the sets that were executed, and such it keeps the value it had at the beginning of the execution. This may be a known issue or it might just be me using the tools in the wrong way, does anyone have any advice? I can manually set the variable to the value I need after each run but it would be better if the last line of the pre-request script
pm.environment.set(“runnerCounter”, Number(pm.environment.get(“runnerCounter”)) + 1);
always worked by setting the environment variable properly.
Also, I did check the Keep variable values as true, so as to persist any variable changes, even though I’m not sure this is necessary when it comes to environment variables.
pm.variables.set is for setting local variables
to set environment variable use pm.environment.set
Note that , it will set only the current value . INitial value remains the same
read more about postman variables
https://learning.postman.com/docs/sending-requests/variables/
I am debugging a program in GDB on linux. I am using getenv and setenv calls to read and set environment variables. For example I am calling setenv("TZ", "UTC", 1); to set the TZ environment variable for timezone.
To check if the env variable is set I am using GDB command show environment. This prints all the environment variables and their values. But it dose not show TZ being set.
Even command show environment TZ says Environment variable "TZ" not defined.
Is their another way to check the environment of the debugged program?
p *(char *) getenv("TZ") reuturns correct value UTC.
The gdb command show environment shows an environment which belongs to gdb [see note], not the environment of the program being debugged.
Calling getenv seems like a totally reasonable approach to printing the running program's environment.
Note
Gdb maintains an environment array, initially copied from its own environment, which it uses to start each new child process. show environment and set environment work on this environment, so set environment will change an environment variable for the next time you start the program being debugged. Once the program is started, the loader will have copied the environment into the program's address space, and any changes made with setenv apply to that array, not the one maintained by gdb.
Addendum: How to print the debugged program's entire environment
On Linux, every process's environment is available through the pseudofile /proc/PID/environ, where PID is replaced by the pid of the process. The value of that file is a list of null-terminated strings, so printing it out takes a small amount of work.
Inside gdb, once you've started running the program to be debugged, you can get its pid with info proc and then use that to print the entire environment:
(gdb) info proc
process 6074
...
(gdb) shell xargs -0 printf %s\\n < /proc/6074/environ
XDG_VTNR=7
KDE_MULTIHEAD=false
...
Of course, I could have done that just as easily outside of gdb, from a different terminal.
You can alter GDB's view of the environment with set environment TZ =UTC but that doesn't affect a running program, only the environment that will be used next time an inferior process is started.
You can inspect a running inferior process' current environment via the global variable environ
I know that getenv() returns a value of specified environment variable of the current user, but my code requires root privileges so getenv() would only use the sudo environment variables. I also know that SUDO_USER tells which user is invoking sudo, which is the user environment I want use for getenv().
char* gnome_env_var = getenv("GDMSESSION"); //returns null as not found in sudo env
char* usr = getenv("SUDO_USER");
Is there a way I can get the value of an environment variable for the logged in user, not the sudo environment?
EDIT
Okay, so what I'm hearing is that the set of environment variables are unique to each process, not user and using sudo to invoke a process with root privileges calls execve which can create an entirely new set of environment variables for that process. So to rephrase, is there a way besides messing with the sudoers file, and within the current process, of finding the calling process's environment variables?
I particularly need the GDMSession environment variable.
getenv doesn't tell you about the environment variables of the current user, but the current process. Users are free to have as many environments as they want(and can create processes), for example with the export shell built-in. In every call to execve, the calling program is free to create an entirely new environment for the executed process.
Therefore, there is no way to get the environment variables of the user, or even those of the process executing sudo. Why do you want that anyways?
You can, however, configure sudo to keep some or all environment variables, via the keep_env and reset_env directives in /etc/sudoers.
There isn't a "user environment." Every process has its own copy of the environment variables. They don't even automatically inherit -- that they appear to is an illusion maintained by the shell and the C library. It is more accurate to think of them as a second set of command line arguments to every program.
So before we can answer your question, you need to clear up what you mean! There are possibilities - none of them are elegant, mind, but they do exist - but they depend crucially on which environment variable you want to get at in which process's state and why.
I have just added the environment variable "DataDir", but the getenv function still returns null value.
Here is my code:
const char *ret = getenv("DataDir");
I restarted my computer and it done.
did you remember to export the variable before running the program? If you are using bash shell on linux, for example, you generally should use export DataDir="..."
On windows, if you set the environment variables using the system settings window, it will not immediately propagate to all of the running programs. If "I restarted my computer and it done." means "restarting the computer resolved the issue", then I believe that explains the problem. After changing the environment variable, try closing all programs and then start a CMD session (or visual studio) and run the program again
Are you running on Windows? Did you set the environment variable through the control panel? If so, that only affects processes that you start (programs that you launch) after you changed the setting. If you're running from a command prompt, and the command prompt didn't inherit the new environment variable, then your program won't inherit it either.
After rebooting, all new processes inherit the new environment variable.
On the other hand, if you set the variable and then run the program:
C:\>set DataDir=blah
C:\>.\my_program
then your program will inherit the variable (but it won't persist across a reboot).
Similar considerations apply on Linux and other systems, but the details differ.
Note that I'm only guessing, based on the symptoms you reported, what system you're using. In the future, it would be helpful to provide that information in the question (if it's not relevant we can ignore it).
I have a FastCGI application that loads and processes a lot of data during its startup. And I want it to get some environment variable to determine its input data path, but as much as I understand so far, environment pointer envp comes with the request.
I want to do getenv before the very first request, say directly after FCGX_Init(). Is it possible?
Yeah, as it turnes out, the lighttpd's counterpart to -initial-env is "bin-environment" array in the fastcgi.server section of lighttpd.conf. The values defined there are accessible for getenv() from the very beginning of execution.