（linux系统）用户数据信息获取getpwuid、getspnam

根据用户名区验证用户名密码是否正确

函数说明

The getpwnam() and getpwuid() functions return a pointer to a passwd structure, or NULL if the matching entry is not found or an error occurs. If an error occurs, errno is set appropriately. If one wantsto check errno after the call, it should be set to zero before call.

getpass() --get a password,用于获取用户输入的密码，取消了输入的回显功能 struct passwd *getpwnam(const char *name); struct passwd *getpwuid(uid_t uid);

passwd结构体

The passwd structure is defined in <pwd.h> as follows: struct passwd { char *pw_name; /* username */ char *pw_passwd; /* user password */ uid_t pw_uid; /* user ID */ gid_t pw_gid; /* group ID */ char *pw_gecos; /* user information */ char *pw_dir; /* home directory */ char *pw_shell; /* shell program */ };

验证用户密码代码

#include<stdio.h> #include<stdlib.h> #include<unistd.h> #include<shadow.h> #include<string.h> #include<crypt.h> #define _XOPEN_SOURCE /* See feature_test_macros(7) */ int main(int argc, char *argv[]) { struct spwd *shadowline; char *crypted_pass; char *input_pass; if(argc<2) { fprintf(stderr,"Usage...\n"); exit(1); } //口令获取 input_pass=getpass("PassWord:"); shadowline=getspnam(argv[1]); crypted_pass=crypt(input_pass,shadowline->sp_pwdp); if(strcmp(shadowline->sp_pwdp,crypted_pass)==0) puts("OK!"); else puts("failer!"); exit(0); } ## 根据ID显示用户名代码 ```c #include<stdio.h> #include<stdlib.h> #include<sys/types.h> #include<pwd.h> int main(int argc,char *argv[]) { struct passwd *pwdline; if(argc<2) { fprintf(stderr,"Usage...\n"); exit(1); } pwdline=getpwuid(atoi(argv[1])); puts(pwdline->pw_name); exit(0); }

调用示例