seek and fgets and fputs fopen

[dave]

In c is it possible to open a file for read write and without using a buffer
or second file change one character in the file and close it modified form

ex.
status.txt contains:
This is mode 1.

change to

This is mode 3

 

[Gianni Mariani]

In c is it possible to open a file for read write and without using a buffer
or second file change one character in the file and close it modified form

see:

std:stream::seekp
std:stream::write

 

[BobR]

dave wrote in message ...

In c is it possible to open a file for read write and without using a buffer
or second file change one character in the file and close it modified form

ex.
status.txt contains:
This is mode 1.

change to

This is mode 3

std::fstream Zstat("status.txt", std::ios:ut | std::ios::binary);
Zstat.seekp( 13 );
if( not Zstat ){
using std::cout; // for NG posting
cout<<" file error="<<Zstat.flags()<<std::endl;
cout<<" ios::good="<<Zstat.good()<<std::endl;
cout<<" ios::bad="<<Zstat.bad()<<std::endl;
cout<<" ios::eof="<<Zstat.eof()<<std::endl;
cout<<" ios::fail="<<Zstat.fail()<<std::endl;
}
else{
Zstat << "3";
}

 

[dave]

dave wrote in message ...


std::fstream Zstat("status.txt", std::ios:ut | std::ios::binary);
Zstat.seekp( 13 );
if( not Zstat ){
using std::cout; // for NG posting
cout<<" file error="<<Zstat.flags()<<std::endl;
cout<<" ios::good="<<Zstat.good()<<std::endl;
cout<<" ios::bad="<<Zstat.bad()<<std::endl;
cout<<" ios::eof="<<Zstat.eof()<<std::endl;
cout<<" ios::fail="<<Zstat.fail()<<std::endl;
}
else{
Zstat << "3";
}

how bout using fopen with *FILE and fputs

 

[BobR]

dave wrote in message ...

how bout using fopen with *FILE and fputs

Why, when you have std::fstream?

std::ifstream Ping("Some.png", std::ios_base::binary );
std::vector<unsigned char> Image;
char In(0);
while( Ping.get( In ) ){
Image.push_back( static_cast<unsigned char>( In ) );
}
std::cout<<"\n Image.size() = "<<Image.size()<<" bytes."<<std::endl;