mis.rar_用户信息

#include <stdio.h> #include <stdlib.h> #include <fcntl.h> #define USER_FILE "user.dat" typedef int (*MENU) (void); typedef int (*ONMENU) (void); typedef struct tag_User { char name[256]; char passwd[256]; } USER; void menuLoop (MENU menu, ONMENU onMenu[], size_t menus) { for (;;) { int idMenu = menu (); if (idMenu < 0 || menus <= idMenu) printf ("无效选择！\n"); else if (onMenu[idMenu] () < 0) break; } } int menuLogin (void) { printf ("------------\n"); printf ("学生管理系统\n"); printf ("------------\n"); printf ("[1] 注册 \n"); printf ("[2] 登录 \n"); printf ("[0] 退出 \n"); printf ("------------\n"); printf ("请选择："); int idMenu = -1; if (scanf ("%d", &idMenu) != 1) scanf ("%*[^\n]"); return idMenu; } int menuStudent (void) { printf ("------------\n"); printf ("学生管理系统\n"); printf ("------------\n"); printf ("[1] 增加学生\n"); printf ("[2] 删除学生\n"); printf ("[3] 浏览学生\n"); printf ("[0] 注销 \n"); printf ("------------\n"); printf ("请选择："); int idMenu = -1; if (scanf ("%d", &idMenu) != 1) scanf ("%*[^\n]"); return idMenu; } int onRegister (void) { USER userNew; printf ("用户名："); scanf ("%s", userNew.name); printf ("密码："); scanf ("%s", userNew.passwd); int fd = open (USER_FILE, O_RDWR | O_CREAT, 0644); if (fd == -1) { perror ("open"); return -1; } USER userOld; ssize_t bytes; while ((bytes = read (fd, &userOld, sizeof (userOld))) > 0) if (! strcmp (userOld.name, userNew.name)) { printf ("用户名已存在，注册失败！\n"); close (fd); return 0; } if (bytes == -1) { perror ("read"); close (fd); return -1; } if (write (fd, &userNew, sizeof (userNew)) == -1) { perror ("write"); close (fd); return -1; } close (fd); printf ("注册成功！\n"); return 0; } int onAdd (void) { printf ("录入学生信息...\n"); return 0; } int onDel (void) { printf ("删除学生信息...\n"); return 0; } int onBrowse (void) { printf ("浏览学生信息...\n"); return 0; } int onLogout (void) { return -1; } int onLogin (void) { USER userLog; printf ("用户名："); scanf ("%s", userLog.name); printf ("密码："); scanf ("%s", userLog.passwd); int fd = open (USER_FILE, O_RDONLY | O_CREAT, 0644); if (fd == -1) { perror ("open"); return -1; } USER userOld; ssize_t bytes; while ((bytes = read (fd, &userOld, sizeof (userOld))) > 0) if (! strcmp (userOld.name, userLog.name)) if (strcmp (userOld.passwd, userLog.passwd)) { printf ("密码错误，登录失败！\n"); close (fd); return 0; } else break; if (bytes == -1) { perror ("read"); close (fd); return -1; } if (bytes == 0) { printf ("用户名错误，登录失败！\n"); close (fd); return 0; } close (fd); ONMENU onMenu[] = {onLogout, onAdd, onDel, onBrowse}; menuLoop (menuStudent, onMenu, sizeof (onMenu) / sizeof (onMenu[0])); return 0; } int onQuit (void) { return -1; } int main (void) { ONMENU onMenu[] = {onQuit, onRegister, onLogin}; menuLoop (menuLogin, onMenu, sizeof (onMenu) / sizeof (onMenu[0])); return 0; }