A quick way to test if an IP belongs to a TOR Exit node.

Uses the new DNS Exit Node querying method (newer than the comparing to list file, April 2020)

Also check out nodeJS port of this project

#include <tor-detector.h>
int main (){
    char ipBuffer[16];
    scanf("%15s",ipBuffer);
    int isExit = isExitNode(ipBuffer);
    return !isExit;
}

Don't forget to link!

make lib
cp libtor-detector.so $YOUR_PROJECT_DIR/libs
cd $YOUR_PROJECT_DIR
gcc -L libs your-code.c -l tor-detector -o your-app

#include <tor-detector.c>
int main (){
    char ipBuffer[16];
    scanf("%15s",ipBuffer);
    int isExit = isExitNode(ipBuffer);
    return !isExit;
}

I'm sure you can compile it yourself.

Hint: gcc your-code.c -o your-app

gcc -Wall -Werror -Wextra main.c tor-detector.c -o tor-detect
./tor-detector 1.2.3.4 # insert your ip here

Due to a bug within glibc's getaddrinfo implementation, (I have glibc 2.35-0ubuntu9) when it returns ENOADDR, there is a chance it might return null pointer to the library but forget to free the buffer it allocated itself. This will cause a memory leak or a segmentation fault if the IP address given was not a tor exit IP address, however extensive testing is required to see the actual impact.