🚀 go-pugleaf

vincent@datmuc.UUCP (vincent) writes:
> 
> #include	<fstream.h>
> #include	<iomanip.h>
> 
> main (int argc, char **argv)
> {
> 	fstream ci;
> 	char s [3];
> 
> 	ci. open (argv [1], ios::in | ios::binary);
> 	ci. unsetf (ios::skipws);
> 
> 	s [1] = '_';
> 	s [2] = '\0';
> 
> 	while (ci. good ()) {
> 		ci >> s [0];
> 		if (ci. eof ())
> 			break;
> 		cout << s;
> 	}
> }
>
> Looks benign, well it is. BUT I've got a problem with it.
> My input file contains "Hello World!"
> My output is:
> 
> __e_l_l_o _W_o_r_l_d_!_


The problem, if somebody hasn't answered by now, is that in binary
mode the input will not have the automatic translation of 
the linefeed and carriage return characters to '\n'.  Sooooo, what
end up happening is that after print out

H_e_l_l_o _W_o_r_l_d_!_

you're programming then reads the linefeed char and puts into
your s array: s[0] = '\l', s[1] = '_', s[2] = 0
and end up moving the cursor to the begginning of the line and
overwriting your 'H' char with the '_' char.
I'm sure you can see fixes for this. Here's one (untested):

 	while (ci. good ()) {
 		ci >> s [0];
 		if (ci. eof ())
 			break;
		if (s[0] == '\0x0A') { // do look ahead 1 char for LF
			char tchar;
			ci >> tchar; // get next char
			// option taken: ignore LF char + EOF
			// option not taken: print s then break
 			if (ci. eof ()) break;
			// translate LF-CR to '\n'
			if (tchar == '\0xD') cout << '\n';
			// print LF and look ahead char
			else { cout << s; s[0] = tchar; cout << s }
		} else cout << s; // no look ahead necessary
 	}
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