On Sun, Jan 4, 2009 at 5:54 PM, niamathullah sharief <[email protected]> wrote: > > can you tell me what is this sysfs....its general system call?
Yes its a virtual filesystem showing device topology. sysfs is mounted in '/sys' directory if not mounted use this command #mount -t sysfs sysfs /sys browse to /sys directory to view this topology. you will see the following things: block bus class dev devices firmware fs kernel module power You must be familiar with kobjects to understand sysfs better. Refer Linux Kernel Development,by Robert Love. ch 17 > --- On Sat, 3/1/09, Robert P. J. Day <[email protected]> wrote: > > From: Robert P. J. Day <[email protected]> > Subject: Re: ioctl() > To: "Rohit Sharma" <[email protected]> > Cc: "rishi agrawal" <[email protected]>, [email protected], "Kernel > newbies" <[email protected]> > Date: Saturday, 3 January, 2009, 8:42 PM > > On Sat, 3 Jan 2009, Rohit Sharma wrote: > >> ioctls are also known as generic system calls. Its a simple switch >> case implementation inside a device. >> you send command and argument through ioctls as parameters. >> Its a way you use to interact with the device itself. >> >> for using it just open the device and use its fd to invoke ioctls. >> >> for eg. >> >> fd = open("/dev/mydev", O_RDONLY); >> >> ioctl(fd, cmd, argument); >> >> >> its internal representation is something like: >> >> ioctl( struct file *, struct inode*, unsigned int cmd, unsigned long arg) >> { >> switch(cmd) { >> case 1: ....... >> case 2: ......... >> } >> } >> >> for more details refer Beginning Linux Programming. >> I hope that helps. > > the last i heard, while ioctl's aren't going away any time soon, > they're deprecated in favour of ... uh, files under /sys? am i > remembering that correctly? in short, if you're already working with > an ioctl-based code base, keep doing that. but if you have the > opportunity to design some kernel code from scratch, use the sysfs. > > or am i way off base here? > > rday > -- > > ======================================================================== > Robert P. J. Day > Linux Consulting, Training and Annoying Kernel Pedantry: > Have classroom, will lecture. > > http://crashcourse.ca Waterloo, Ontario, CANADA > ============================================================ > ============ > > -- > To unsubscribe from this list: send an email with > "unsubscribe kernelnewbies" to [email protected] > Please read the FAQ at http://kernelnewbies.org/FAQ > > > ________________________________ > Add more friends to your messenger and enjoy! Invite them now. -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to [email protected] Please read the FAQ at http://kernelnewbies.org/FAQ
