原创 第六章——系统数据文件和信息

yannzi:x:1000:1000:yannzi User,,,:/home/yannzi:/bin/bash

finger -p yannzi

Login: yannzi                     Name: yannzi User
Directory: /home/yannzi                 Shell: /bin/bash
On since Sun Mar 15 07:29 (CST) on tty7 from :0
On since Sun Mar 15 07:31 (CST) on pts/0 from :0.0
No mail.

vipw 个更改的是/etc/passwd

getpwnam函数的一个实现。
      1 #include <pwd.h>
      2 #include <stddef.h>
      3 #include <string.h>
      4
      5 struct passwd*
      6 getpwnam(const char *name)
      7 {
      8         struct passwd *ptr;
      9 
     10         setpwent();
     11         while ((ptr = getpwent()) != NULL)
     12                 if (strcmp(name, ptr->pw_name) == 0)
     13                         break;
     14         endpwent();
     15         return (ptr);
     16 }