#include 
     
      #include 
      
       char* getEnvWrapper(char* key) {    char* value = getenv(key);    if (!value) {        value = "not found";    }    return value;}int putEnvWrapper(char*  key, char*  value) {    return setenv(key, value, 1);}int main(int argc, char** argv){	if(argc == 2){		char* r = getEnvWrapper(argv[1]);		printf("GetEnv %s = %s\n", argv[1], r);	}else if(argc == 3 ) {		printf("SetEnv => %s:%s\n", argv[1], argv[2]);		int r = putEnvWrapper(argv[1], argv[2]);		printf("GetEnv result code = %d\n", r);	}else {		printf("usage : ./envop key [value]\n");	}}