hey guys i am new to unix and programming in it plz help me.
i have written a code in unix

#include<iostream>
#include<unistd.h>
#include<fcntl.h>
using namespace std;
int main()
{
int fld;
char *buf;
fld=open("manu.txt",1);
cout<<"dsada";
int d=read(0,buf,1);
cout<<"manu";
cout<<d;
return 0;
}


the above code in output window cursor is blinking nothing else happens..

The problem is that the output isn't being flushed. One way to flush is to send a new line (std::endl), or if you don't want a newline, send std::flush. Out of curiosity, why do you open "manu.txt" but never use it? And you might want to find a way to handle the rest of the input (including the newline from the user) or the rest of it will be sent to bash after the program terminates. Maybe read until the newline, and throw the information away.

Also, in order to read something, you need to assign some memory to your buffer, as it is now, you are trying to read a byte from the input into the position pointed to by a pointer that has not yet been assigned, which is a very bad idea. Since you are only using a single byte you should initialize it as
or make it bigger if you like.

1 members found this post helpful.

thanks.

Moved: This thread is more suitable in <PROGRAMMING> and has been moved accordingly to help your thread/question get the exposure it deserves.

For future reference, please post code between [code] tags to preserve indentation.

Also, you don't need to do IO like that. You can use the C++ facilities, e.g.

#include <fstream>
using namespace std;

(irrelevant code omitted)

ifstream in("somefile");
int x;

in >> x;

See, e.g. this.