dev-cpp-users

[Dev-C++] how to do a shell like input..

[<ca...@kr...>]

hi Dev-C++,
[this is a followup thread to 'stdin reset..']

I want to programm a shell-like interface for my application, in which
I know some special commands with options and arguments.

the problem I have is, how do I create an input-buffer, that is able
to hold whatever is read from stdin, since i can not say what would be
the longest valid entry (say cat some large text...).

is there a way to dynamically read the length of the inputstring up to
the first '\n' and then malloc some string and THEN scanf() ???

 
gruss
/Christian                   mailto:ca...@kr...

---


I propose that the following character sequence for joke markers:

:-)

                             19-Sep-82 11:44    Scott E  Fahlman

RE: [Dev-C++] how to do a shell like input..

[Ioannis V. <iv...@at...>]

> -----Original Message-----
> From: dev...@li...=20
> [mailto:dev...@li...] On Behalf=20
> Of Christian Sch=E4fer
> Sent: Saturday, April 26, 2003 10:29 AM
> To: Dev-C++ Mailing List
> Subject: [Dev-C++] how to do a shell like input..
>=20
>=20
> hi Dev-C++,
> [this is a followup thread to 'stdin reset..']
>=20
> I want to programm a shell-like interface for my application, in which
> I know some special commands with options and arguments.
>=20
> the problem I have is, how do I create an input-buffer, that is able
> to hold whatever is read from stdin, since i can not say what would be
> the longest valid entry (say cat some large text...).
>=20
> is there a way to dynamically read the length of the inputstring up to
> the first '\n' and then malloc some string and THEN scanf() ???


You can use a temporary buffer in the automatic storage of a fixed size
where you will store using getchar(), and then use malloc() and =
realloc() to
allocate the necessary space on the free store and strcat() from the =
temp
buffer... In C++ you would simply do:


string s;

while(cin>>s)
     ;



Ioannis Vranos
=20
* Programming pages: http://www.noicys.freeurl.com
* Alternative URL 1: http://run.to/noicys
* Alternative URL 2: http://www.noicys.cjb.net


Anti-racism movement: http://www.positive-youthfoundation.org
Iraq Peace Pledge: http://www.peacepledge.org


Ioannis Vranos
=20
* Programming pages: http://www.noicys.freeurl.com
* Alternative URL 1: http://run.to/noicys
* Alternative URL 2: http://www.noicys.cjb.net


Anti-racism movement: http://www.positive-youthfoundation.org
Iraq Peace Pledge: http://www.peacepledge.org

Re[2]: [Dev-C++] how to do a shell like input..

[<ca...@kr...>]

hi!

ok, then I got down to this little snippet. thanks to your help.
a buffer overflow won't come I think but can there be a EOF before
'\n' on stdin???

<snip>
    #define BUFFER_MAX_SIZE 4096    // <- I think this limit is even
                                    //    used in the bash
    int i = 0;
    char c;
    char buffer[BUFFER_MAX_SIZE];

    while((c = getchar()) != '\n')
        if(i < BUFFER_MAX_SIZE) buffer[i++] = (c == '\n') ? 0 : c;
</snap>

 
gruss
/Christian                   mailto:ca...@kr...

---


I propose that the following character sequence for joke markers:

:-)

                             19-Sep-82 11:44    Scott E  Fahlman

Re[3]: [Dev-C++] how to do a shell like input..

[<ca...@kr...>]

>     #define BUFFER_MAX_SIZE 4096    // <- I think this limit is even
>                                     //    used in the bash

I thought about using a small buffer for starters and then reallocate
memory when needed but that seemed much to inefficient to me, since
realloc whether adds very often very little space or not so often a
lot of space to the string. so you either end up with very much
performance on reallocating tiny additions to the buffer or with a
too long buffer in which case you could've use a large buffer in the
first place. so that's what I'm doing I guess. ;)

 
gruss
/Christian                   mailto:ca...@kr...

---


I propose that the following character sequence for joke markers:

:-)

                             19-Sep-82 11:44    Scott E  Fahlman