Dear Sirs,
I use the gcc 3.3.5 20050117 prerelease that came with SuSe 10 and have a
problem and a question.
The problem first:
When debugging programs like this:
quote
-----
using namespace std;
#include <iostream>
#include <cstring>
class Nwh {
char Firstname [12];
int age;
public:
Nwh ( char * Firstname_, int age_ );
}; // class Nwh {
Nwh :: Nwh ( char * Firstname_, int age_ ) {
strcpy ( Firstname, Firstname_ );
age = age_;
} // Nwh :: Nwh ( char * Firstname_, int age_ ) {
int main ( ) {
Nwh Me ( "Hans", 15 );
cout << "Done";
return 1;
} // int main ( ) {
unquote
-------
I can put a breakpoint in the subprogram, gdb says it has been put, but it
never stops there, and stepping through the program I see it pass my break. Of
course I collided to it in more complicated sources.
---
My problem is this:
Stroustrup: The C++ ... is very cumbersome to understand after chapter 20 or
so. I frequently have the problem to read ( sequence of charstrings, integers
and doubles ) as lines from a file built by some other program or by myself as
a form in textmode. `sscanf` has always been a stepchild for C and C++, and
the debugger handles it terribly. Integers and doubles read correctly by
`sscanf ( s+60, "%lf", Myint )` are OK when printed ( `cout << ...` ), but gdb
gives them as e.g. 3.43567655+345.
Stroustrup ch 20 and 21 give very little information on sprintf, and only
mentions sscanf once. On internet Google search on "C++ tutorial sstream"
gives > 800 hits, but only three really on sstreams and 1, maybe 2 can be
used.
But I have, as said, to read from a file ( `is.getline ( line, 200 )` ) a line
formatted as an 2 integers from position 10, resp 20, a string on positions 30
- 70, and a number of doubles at well-defined positions after that.
The string may include spaces, and that is the problem since a stringstream
thinks it has done what I asked for as soon as it finds a space, so I have to
tell him that he should read all 40 chars, no matter the contents are and then
start reading the trailing doubles. In the sources I can't find the
solution. setw(40) does not help me out. So I need some formatting directives
for sstream, such as `an integer from positions 1 to 10; possibly another
integer from positions 11 - 20; a string of chars, including spaces from
positions 30 - 70; ...' .
I have been looking in the gnu.org/onlinedocs manuals, but found nothing like
'<sstring>'.
Can you please tell me how to solve my problem?
A second question is: How must I interpret the avalanche of @'s in
/usr/include/c++/3.3.5/ files?
If you find in my internetsite a reason for cooperation, I will be happy to
discuss that. In these days I make mainly diskutilities like signalling
double, triple, quadruple, ... files on 500 GB background memory, a standard
format for all kinds of textfiles etc.
Nieuwenhuizen, J.K.
2006-03-05T15:10
--
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Prof. Ir. J.K. Nieuwenhuizen email: [EMAIL PROTECTED]
dom Paul Bellotweg 8 internet: www.nieuwenhuizen-jk.nl
5624 KZ Eindhoven
Netherlands Tel : [{00xx|0}40] 2442226
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