RE: [Dev-C++] BC++, gcc and Win98SE shell

[Ioannis V. <no...@ya...>]

> -----Original Message-----
> From: dev...@li... 
> [mailto:dev...@li...] On Behalf 
> Of gi...@li...
> Sent: Monday, February 25, 2002 12:38 AM
> To: dev...@so...
> Subject: RE: [Dev-C++] BC++, gcc and Win98SE shell
> 
> 
> Sorry for my previous post, it was not very clear.
> 
> Let me try again.
> 
> The test program is, this time, a little different:
> 
> /* echo.c */
> #include <stdio.h>
> int main(int argc, char *argv[])
> {
>     while (--argc > 0)
>        printf("%s%s", *++argv, (argc > 1) ? " ": "");
>     printf("\n");
>     return 0;
> }
> 
> IMHO the above is more or less equivalent to the program I 
> posted before 
> but I changed in the hope that Ioannis won't yell at me this time :-)
> 
> Anyway the program is not the point, it is just a mean to 
> show that: when I use a program compiled by gcc, it seems 
> that the shell expands 
> wildcards before invoking the program (as it should always 
> be), instead 
> when I compile the same program using BC++, the shell does 
> not expand the 
> wildcards.
> 
> To prove it, what I did was:
> 1. create a directory named c:\temp
> 2. used the program "touch" (a Borland tool) to create: 
> c:\temp\foo.c and 
> c:\temp\bar.c
> 3. switched to the directory c:\temp
> 4. issued the command: echo_g *.c
> 
> The ouput of the command was:
> 
> bar.c foo.c
> 
> This means that the shell expanded "*.c" into "bar.c foo.c", the two 
> arguments were then echoed by the program "echo_g" (where the 
> "_g" means 
> compiled using gcc).
> 
> Instead if I use the version of echo compiled by BC++ (named 
> "echo_b.exe"), 
> that is, when step #4 becomes:
> 
> 4. issued the command: echo_b *.c
> 
> The output is:
> 
> *.c
> 
> This means that the shell did not expand "*.c". Or, if you 
> prefer, I have 
> the same  ANSI C89 program give two different outputs, 
> according to which 
> compiler was used to build the executable. I have no 
> explanation for this, 
> other than there is some bug in the shell.


This is compiler bug. **argv represents the passed arguments as a string
and i think that the behavior of BCC is the correct  (expected) here.
The standard requires the exact arguments to be represented as C-strings
in *argv[] and then if the programmer wishes he can execute system
commands like system("dir *.c");

The C  & C++ standards write:

"int main(int argc, char* argv[]) { /* ... */ }

In the latter form argc shall be the number of arguments passed to the
program from the environment in
which the program is run."



> 
> My questions are
> 1. Why is the Windows shell (or command.com, if you prefer) acting 
> differently?


I do not think it is the environment. I rather think is the use of the
environment from the produced exe (produced by the compiler).


> 2. Is this happening on my Win98SE or is it happening on 
> other versions of 
> Windows too?


It is happening in my win2k too and i use the cmd.exe .



Ioannis
 
* Ioannis Vranos
* Programming pages: http://www.noicys.d2g.com
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