Re: [linuxiran] [OT] C programming, variable size array

[Arash Partow]

> be khatere hamin fekr nemikonam marbot be ANSI ya POSIX bashe!
> be in dalaiel estefade nemikonan !

1.)what are you basing this on?
2.)have you read the POSIX specifications?


Regards


Arash


__________________________________________________
Be one who knows what they don't know,
Instead of being one who knows not what they don't know,
Thinking they know everything about all things.
http://www.partow.net




----- Original Message ----- 
From: "Mohammad Reza Ghorbani" <address@hidden>
To: "GNU/Linux in Iran" <address@hidden>
Sent: Saturday, December 13, 2003 3:17 PM
Subject: Re: [linuxiran] [OT] C programming, variable size array


> On Saturday 13 December 2003 00:51, Aryan Ameri wrote:
> >   exit(EXIT_SUCCESS);
> >    /*
> >     proper posix way to exit.
> >    */
> >    return 0;
> >
> > Which one do you mean is the proper POSIX way of exiting? the exit
> > function? or return 0? I always put return 0; though my incompetent
> > instructor doesn't even put it. But I haven't seen the exit() function
> > before, well, I haven't studdied the POSIX standard !!!
> >
> > Also, what does sizeof() do? from the code it seems to me it is used for
> > counting. Am I right?
> >
> > You use if (((char)tempValue) == EOF) to determine EOF. I
> >
> >
> > The way I have learned, I use the getchar() function to do so, as in
> > while ( (tmp = getchar() ) != EOF )
> >
> > Any advantages to any method?
> >
> > Also now that I am here, let me abuse your knowledge, and ask one more
> > thing. I just learned the gets() function, and when I use it on my gcc
> > 3.2, it gives me a "the gets function is dangerous. It shouldn not be
> > used" warning. I guess gets is now deprecated, but it is still being
> > tought in our univ. Do you know what is the correct way of inputting a
> > string of characters, not using gets ?
> >
> > Thanks again, very very much.
> >
> > Cheers
>
> Salam . . .
>   Aval mazerat mikham ke fingilish minivisam ! :( chon zabanam kheili bad
> hastesh ! ama mohem nist :
>
> dar morede soale avalet ke farghe "exit(EXIT_SUCCESS);" ba "return 0" bood
> bayad begam ke agar dar akhare barname estefade beshan TAGHRIBAN hich
farghi
> ba ham nadaran.ama betore koli az "exit(int)" baraye khoroje gheyre normal
ya
> "ABNORMAL" estefade mishe.va baraye manteghe barname nevisi dorost nist
> darhalate normal az on estefade konim.(hatman midoni har meghdari ke
main()
> return kone dar ENVAIROMENT VARIABLE e '$?' zakhire mishe ke ba shell
> mitooni befahmi ke barname ba che error_codi kharej shode).
> ama ye farghe kocholo baham daran ke momkene kasi az "exit(EXIT_SUCCESS);"
> be jaie rerurn 0;"estefade kone (ama man jaie nadidam" :
> bebin vaghti barnameie ma tamom mishe ye seri etefagh barash miyofde:
> masalan:
> 1. agar TEMP FILE dasfte bashi ke khodet close nakarde bashi on "FILE *"
close
> mishe.
> 2.ya buffere STDIO, flush mishe va gheire !
> va momkene yeki bekhad az vasate barname NORMAL kharej she ! :-o
> return faghat male vaghtie ke reside bashi be akhare block!
> vali akhare barname hich farghi baham nadaran!
> ye chize dige ham begam :
> bebin ye farghi mohem return ba exit dare :
> return KeyWord hastesh va exit Function !
> Performance KeyWord ha az Function ha kheili bishtare .
> elatesham in ke KeyWord OVER_HEAD nadare vali function dare!
> to C/C++ performance barname baromon kheili moheme!
> baraye hamin ba return 0 barnamaro tamom mikonim!
> be khatere hamin fekr nemikonam marbot be ANSI ya POSIX bashe!
> be in dalaiel estefade nemikonan !
> --------------------------------------------------------------------------
---------------------------------------------------------
> ye chize dige baraye EOF begam !
> mamolan to linux rasm bar ine ke barname haie ke az Terminal mikhan faghat
> vorodie chand khati begiran (MESLE PHP interpreter) vgahti kare user tamom
> shod,user bayad ye "CONTROL + C" bezane.
> in jori chi mishe ?
> ye Signal be barname ferestade mishe be esme SIGINIT ke barname nevis in
> signalo handel(catch) mikone! yani to barnamsh mige vaghti in signal resid
ye
> kari bokon!
> agar dost dashti fekr mikonam az in ghabliyat estefade koni barnamat
khoshgel
> mishe!
> chon nemidonam cheghadara ba signal ashnaie bishtar tozih nemidam! vali
> agar khasti mitoni behem begi ke baz barat begam!
> --------------------------------------------------------------------------
--------------------------------------------------------
> ye chize dige :
> gets tole vorodi ro chek nemikone va ta vaghti ke user '\n' type kone
vorodi
> migire! khob in kheili bade! momkene to ye 'char str[20]' tarif koni vali
> tosh 45 CHAR berzan.in jori 25 khoneie badie hafezat kharab mishe!
> va aslan malom nist chi be sare barnamat miyad!
> agar esme BUFER_OVERFLOW ro shenide bashi bayad begam ke hameie in
> exploit ha to interenet baraye deghat nakrdan be hamin moshkelat e!
>
> baraye hamin agar to dashte bashi :
> char str[20];
> behtare benivisi:
> fgets(str ,20 ,STDIN);
>
> in khat daghighan kare hamono mikone vali kheili behtare !
> --------------------------------------------------------------------------
--------------------------------------------------------
> dar akhar pish nahad mikonam :
> http://www.advancedlinuxprogramming.com
> ro bekhoooonin !
> -------------------------------------------------------------------------
>      Ghorbanat
> Mohammad Reza
>      7 : 39 am
>
>
>
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>
>