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Questions tagged [getenv]

Anything related to C or C++ standard library functions `getenv` (C) or `std::getenv` (C++). These functions are used to get the value of an environment variable.

Anything related to C or C++ standard library functions getenv (defined in <stdlib.h> C standard header) or std::getenv (defined in <cstdlib> C++ standard header). These functions are used to get the value of an environment variable.

See CPPreference.com:

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Why this piece of code can get environment variable address?

64-bit Linux stack smashing tutorial: Part 1 uses Get environment variable address gist to get environment variable address. The prerequisite is to first disable ASLR via echo 0 > /proc/sys/kernel/randomize_va_space. The content of the gist is: /* …
Jingguo Yao
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which is better between getting hostname using InetAddress or System.getenv

I posted a question about a problem that concerns inetaddress in java 8 : InetAddress java 8 is not getting the hostname however I found a simple solution by using System.getenv("HOSTNAME") instead of InetAddress.getLocalHost().getHostName()... I…
Mohamed Taboubi
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AppData / Similar for all OS : C++?

I'm looking to store some "preferences" for my C++ application. Under windows I know I have to use the "AppData" folder, but I need the equivalent for Linux and OsX. Is there some library or portable way to get such information in C++ ? Here is the…
ClubberLang
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chdir(getenv("HOME") prompts error "No such file or directory"

Being quite new to writing shell. I am trying to get "cd" to go to home directory when I don't give any extra argument. But when I call "cd" and the code tries to chdir(getenv("HOME")), it shows an error message "No such file or directory". /* …
donkey
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Which environment variables the app is using

I have binary executable file compiled from C-source and I know that it uses some of UNIX system environment variables. Unfortunately I have no documentation and decompiling/reverse-engineering is very difficult. Is there a way to find which env…
Aleksei Petrenko
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Strange behaviour for setenv & getenv in OS X Yosemite

When I set an environment variable launchctl setenv FOO test I can fetch the value by launchctl getenv FOO which returns me 'test', but a simple echo $FOO doesn't substitute, the result is empty. In same terminal as well as in new…
ctp
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getenv() returns null within a MySQL UDF

I'm experiencing a strange issue with the C/C++ function getenv(). The function is used within a MySQL UDF on a Linux system (Linux Mint 16 Cinnamon 64bit). I've set the JAVA_HOME environment variable system-wide by editing the file /etc/environment…
user46726
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using getenv and env doesn't give the same results:

I have a C program that prints every environmental variable, whose name is given by stdin. It prints variables such as $PATH, $USER but it doesn't see the environmental variables that i defined myself in the Linux shell... For instance, in ~.bashrc…
user2177446
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getenv returns null when asked for the username?

I want to get the username using the stdlib functio getenv ()However I always get NULL here is the code that I have written: #include #include main() { char *hai; printf("The current User name is\n"); hai="USER"; …
user1680944
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warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]

I was learning C with a book called "C in Linux" by David Haskins but there's a problem. When i try to compile this code: #include #include int main (int argc, char *argv[], char *env[]) { …
user2680683
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PHP getenv results in MAC address not IP

New so maybe a problem with correct use however; Developing a php /web based ordering system needing to identify device (browser) when placing order. Currently using getenv: $terminal = getenv('REMOTE_ADDR'); Majority of results as expected -…
user2570883
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getenv in Visual C++ 2012

I want to use a getenv function from C in my C++ project in Visual Studio 2012. The code: extern "C" System::SByte^ getenv(const System::SByte^ name); and then in some function: String^ h1 = "HOMEDRIVE"; const System::SByte^ c1 = dynamic_cast
user2383085
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Stack smashing detected and no source for getenv

I'm having the weirdest problem ever when programming in C. My function sometimes runs and other times it doesn't, and even though I tried searching for these errors (stack smashing detected and no source for getenv) I can't seem to find the answer…
PL-RL
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Implementing environment variables in simple linux shell

I am to program a simple shell in linux that can implement various stuffs including environment variables. I tried printing these variables using getenv but I have some problems. getenv always return NULL even if the user types a correct variable…
mkab
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(C) How do I include a directory path after a getenv()?

I have been trying to figure out how to (in C) put "getenv()" and "/filetest" into one char. I've thought that you could do it by putting: char *file = getenv("HOME") + "/filetest"; But, I can't seem to figure it out. I tried after that to do: char…
0NeXt
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