I am writing small c++ code to access and edit certain text file in user's home directory. Currently I have following code (this is the relevant part):
bool core(void) {
std::string autostart_entry = "";
std::string user_entry = "";
std::fstream username;
username.open("username.txt", std::fstream::in);
std::string location;
std::string user_name;
if (username.fail()) {
username.open("username.txt", std::fstream::out);
std::cout << "What's your system username? ";
std::getline(std::cin, user_name);
username << user_name;
}
else
username >> user_name;
username.close();
location = "/home/" + user_name + "/.config/openbox/autostart";
...
}
This way, as you can see, I ask user for his username, and append it to the location string, is there any easy way to find user's home directory without asking for user's input? I have tried "~/..." and it doesn't work.
I know I could scan "/etc/passwd" file to find it from there but I am wondering if there is another way.
Your best bet here is probably to use the getenv function:
#include <stdlib.h>
const char* homeDir = getenv("HOME");
The $HOME environment variable is generally always set under linux, and it will return you a string to a users home directory (even when it isn't under /home)
EDIT: This will only work for the home directory of the user running the program. If you want the home directory for a different user, you will need to use another approach
EDIT2: Actually, thinking about this for more than 1 second... the above will work, and you should use it first. However, if HOME is not set, you can use getpwuid:
#include <unistd.h>
#include <sys/types.h>
#include <pwd.h>
const char *homedir = getenv("HOME");
if ( homedir == NULL ) {
homedir = getpwuid(getuid())->pw_dir;
}
If you wanted to go to the home directory, just use chdir("~")
else,
This is a dirty hack but it works
#include <unistd.h>
char currdir[100];
char homedir[100];
getcwd(currdir); //store the current directory in currdir
chdir("~"); // change the working directory to user's home directory
getcwd(homedir); // get the full address
chdir(currdir); // go back to the previous directory