linux - 在 rpc 中登录的用户数

Question

我是 rpc 的新手，即我处于学习阶段，我想找出从以下程序登录的用户数我像这样编译“cc samrpc.c -lrpcsvc”但是它显示的错误和警告是

     samrpc.c: In function ‘main’:
 samrpc.c:9:1: warning: incompatible implicit declaration of built-in function ‘exit’       [enabled by default]
  samrpc.c:13:1: warning: incompatible implicit declaration of built-in function ‘exit’    [enabled by default]
/tmp/ccxyIUNJ.o: In function `main':
samrpc.c:(.text+0x51): undefined reference to `rnusers'
collect2: error: ld returned 1 exit status

你能详细告诉我如何编译这个程序吗？我需要什么要求？注意:samrpc.c是程序名我的程序在下面

 #include <stdio.h>
 int main(argc, argv)
 int argc;
 char **argv;
 { 
 int num;
  if (argc != 2) {
 fprintf(stderr, "usage: rnusers hostname\n");
 exit(1);
 }
 if ((num = rnusers(argv[1])) < 0) {
 fprintf(stderr, "error: rnusers\n");
 exit(-1);
 }
 printf("%d users on %s\n", num, argv[1]);
 return 0;
 }

Answer 1

检查你的代码

ld returned 1 exit status means you have undefined reference to your main function Due to which linker doesn't find a entry point to program

In you code main has not been defined properly your run time argument too have not been passed properly

#include <stdio.h>
#include<process.h>
int main(int argc,char ** argv)
{
 int num;
  if (argc != 2) {
 fprintf(stderr, "usage: rnusers hostname\n");
 exit(1);
 }
 if ((num = rnusers(argv[1])) < 0) {
 fprintf(stderr, "error: rnusers\n");
 exit(-1);
 }
 printf("%d users on %s\n", num, argv[1]);
 return 0;
 }

正确定义main，它应该可以工作