Finding the owner and group of a file (as a string)

Question

I am trying to get a C string of the owner and group of a file, After I do a stat() I get the user ID and group ID, but how do I get the name?

Answer 1

You can use getgrgid() to get the group name and getpwuid() to get the user name:

#include <pwd.h>
#include <grp.h>

/* ... */

struct group *grp;
struct passwd *pwd;

grp = getgrgid(gid);
printf("group: %s\n", grp->gr_name);

pwd = getpwuid(uid);
printf("username: %s\n", pwd->pw_name);