我有下面的代碼，在情況1中我首先嘗試：注冊(cè)一個(gè)新密碼并將其寫(xiě)入文件，此方法有效，在情況2中我遇到的問(wèn)題是：我正在嘗試使用戶(hù)提供一個(gè)密碼以通過(guò)crypt函數(shù)對(duì)其進(jìn)行加密，然后使用先前文件中的所有加密密碼對(duì)其進(jìn)行身份驗(yàn)證。但是，當(dāng)我對(duì)此進(jìn)行編譯時(shí)，出現(xiàn)錯(cuò)誤“ Segmentation Fault”。在我看來(lái)，問(wèn)題將出在log_password和對(duì)加密消息的轉(zhuǎn)換中。任何幫助將是巨大的。#define _GNU_SOURCE#include <stdio.h>#include <time.h>#include <unistd.h>#include <crypt.h>#include <string.h>#include <sys/stat.h>intmain(void){FILE *f=fopen("shadow.txt","a+");    char * line=NULL;  unsigned long seed[2];  char *log_password,salt[] = "$1$........";  const char *const seedchars =    "./0123456789ABCDEFGHIJKLMNOPQRST"    "UVWXYZabcdefghijklmnopqrstuvwxyz";  char *password,*pass;  int i,ans;  /* Generate a (not very) random seed.     You should do it better than this... */  seed[0] = time(NULL);  seed[1] = getpid() ^ (seed[0] >> 14 & 0x30000);  /* Turn it into printable characters from ‘seedchars’. */  for (i = 0; i < 8; i++)    salt[3+i] = seedchars[(seed[i/5] >> (i%5)*6) & 0x3f];  printf("Press 1 for Register.\n");  printf("Press 2 for Login.\n");  printf("Press 3 for Exit.\n");  scanf("%d",&ans);  switch(ans)  {    case 1:             password = crypt(getpass("Password:"), salt);            fprintf(f,"%s \n",password);            printf("Succesfull Register in file\n");            fclose(f);            break;    case 2:             fgets(pass,34,f);            log_password =  crypt(getpass("Login Password:"), pass);            int ok;            ok = strcmp (log_password, pass) == 0;            puts(ok ? "Access granted." : "Access denied.");            return ok ? 0 : 1;            break;    case 3:             printf("Bye\n");            exit(1);            break;    default:             printf("Try Again.\n");            break;  }  return 0;}