p4.3.cxx

linux程序设计例程

/* program p4.3.cxx: using chdir to change current working directory */
#include <unistd.h>
#include <iostream>

int main(void){
   long cur_path_len;
   char* cur_work_dir;
   
   /*获得目录最大长度*/
   if((cur_path_len=pathconf(".",_PC_PATH_MAX))==-1){
      perror("Couldn't get current working path length");
      return 1;
   }

  std::cout<<"Current Path Length Is "<<cur_path_len<<std::endl;

  /*根据获得的目录最大长度，分配内存*/
  if((cur_work_dir=(char *)malloc(cur_path_len))==NULL){
      perror("Couldn't allocate memory for the pathname");
      return 1;
  }

  if(getcwd(cur_work_dir,cur_path_len)==NULL){
      perror("Couldn't get current working directory");
      return 1;
  }

  std::cout<<"Current Working Directory is"<<cur_work_dir<<std::endl;
   
  /*更改当前工作目录到上级目录*/
  if(chdir("..")==-1){
     perror("Couldn't change current working directory");
     return 1;
  }

  if(getcwd(cur_work_dir,cur_path_len)==NULL){
      perror("Couldn't get current working directory");
      return 1;
  }

  std::cout<<"After chdir function call,Current Working Directory is"<<cur_work_dir<<std::endl;

  return 0;
}