Re: [Fwd: Re: Implementing a file counter (like "ls | wc")]

["John T. Williams" <jowillia@vt.edu>]

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I just want to say after much testing, I've gone and proved myself
wrong.  

Anyone interested in playing with the concept I've included the code. 



On Thu, 2004-04-08 at 22:00, A. Murat Eren wrote:
>  Hi,
> 
>  I've read all of the mailing thread about this subject and i'd like to ask 
> some questions..
> 
> > But most important always try to avoid system calls!
> 
>  I guess eveybody is accepting that the syscalls is slowing down the process 
> when invoking them from the critical parts of the code (i hope i understand 
> properly).. I'm trying to write a basic shell for me (just for fun, nothing 
> serious), i'm setting up my user's shell in passwd file to my basic shell's 
> compiled binary, and when i'm logging in from the console, normally i'm 
> falling to a prompt which is written by me.
> 
>  I'm not using the well-known programs such as 'ls', 'cd' etc.. i have my own 
> envoriment variables and my own basic programs those are invoking from my 
> prompt with fork and execvp. If i do not want to use the syscalls such as 
> readdir, opendir what i must do?
> 
>  With readdir, i can read everything from the every type of file system which 
> supported by kernel *transparently*, for example when i'm working on a disk 
> partition which is formatted with ext3 file system i don't have to try to 
> read the superblocks and inode's adresses from disk because VFS takes care 
> all of the low level operations via readdir (and kernel's modules for that 
> file system) for me, isn't it? If i want to do all of them by my self (sure, 
> this is not necessary but i just want to try and learn) which is the right 
> way i have to go? I thought that it would be a very simple and absolute way 
> looking into the glibc for implementations of the functions like readdir, but 
> nearly i'm sure that it would be impossible to undrstand (and this is another 
> problem, i can't understand the source code usually :( it would be great to 
> hear your advices about how i improve my vision).
> 
> 
>  Thanks for your time from now,
>  Regards.

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