topic Re: statvfs systemcall in Operating System - Linux

statvfs systemcall

sodani — Tue, 10 Jun 2008 04:41:14 GMT

Hi,

Call statvfs() on an existing file. Check file system block and inode counts. Check file system ID.

Solution:
=========

#define ExistingFile "/shwetha/readme.htm"

strcpy(DirectoryName,ExistingFile);
fd = statvfs(DirectoryName,&buf);
perror("1.Systemcall statvfs failed on ExistingFile\n");
}
else {
fprintf (stdout,"Systemcall statvfs Success on ExistingFile\n");
if(buf.f_blocks & buf.f_files & buf.f_fsid) {
fprintf (stdout, "successfully verified the the file system block, inode c
ount and file system ID \n");
}
else {
perror ("Failed to verify the the file system block, inode count and file
system ID\n");
}
}

The testcase for checking the file system block , inode counts,file system ID the logic which i used is with & operator.
i think this logic is wrong..
Please let me know how to do this..

Thanks in Advance,
shwetha

Re: statvfs systemcall

Dennis Handly — Tue, 10 Jun 2008 06:08:08 GMT

>Call statvfs() on an existing file.

This looks like an exam or homework question. This forum is not for those questions.

>the logic which i used is with & operator.

Yes, "&" is the wrong operator. Perhaps you want to use "&&" for logical AND. But checking for non-zero doesn't really "verify" anything.

Re: statvfs systemcall

James R. Ferguson — Tue, 10 Jun 2008 10:49:28 GMT

HI:

As Dennis noted, checking a non-zero return status doesn't provide a great amount of information. You would be better to use 'strerror()' and 'errno' to be able to relate errors to those documented in the manpages for 'statvfs()' :

http://www.docs.hp.com/en/B3921-60631/statvfs.2.html

Regards!

...JRF...

Re: statvfs systemcall

Dennis Handly — Tue, 10 Jun 2008 19:05:19 GMT

>JRF: checking a non-zero return status doesn't provide a great amount of information

I wasn't talking about the return status since that wasn't in the above fragment. (A bug)
I was pointing out this if:
if(buf.f_blocks & buf.f_files & buf.f_fsid) {