O_APPEND与读操作

#include <iostream> #include <fcntl.h> #include"unistd.h" using namespace std; int main() { int fd=open("work1",O_RDWR|O_APPEND); if(fd==-1) { cout<<"open work1 error"<<endl; } char buf='z'; if (write(fd,&buf,1)==-1) { cout<<"write error"<<endl; } //else //cout<<write(fd,&buf,1)<<endl; off_t CurrentPoint=lseek(fd,0,SEEK_CUR);//get current lseek point cout<<"CurrentPoint is "<<CurrentPoint<<endl; if (lseek(fd,0,SEEK_SET==-1)) { cout<<"lseek error"<<endl; } off_t NewCurrentPoint=lseek(fd,0,SEEK_CUR);//0 means offset cout<<"the newcurrentpoint is "<<NewCurrentPoint<<endl; char buf1='j'; if (write(fd,&buf1,1)==-1) cout<<"write error"<<endl; //else cout<<write(fd,&buf1,1)<<endl; close(fd); return 0; }