linux用户信息

1. getlogin

char *getlogin (void);

返回用户登录时的用户名

2. getpwuid
getpwnam由login程序使用
getpwuid由ls程序使用

struct passwd *getpwuid(uid_t uid);
struct passwd *getpwnam(const char *name);

strcut passwd
{
    char *pw_name;
    char *pw_passwd;
    uid_t pw_uid;
    gid_t pw_gid;
    char *pw_gecos;
    char *pw_dir;
    char *pw_shell;
}

3. 举例

uid_t userid;
struct passwd* pwd;
userid = getuid();
printf("userid is %d\n", userid);
//pwd = getpwnam("root");
pwd = getpwuid(userid);
printf("username is %s\nuserdir i %s\n", pwd->pw_name, pwd->pw_dir);