how VI reads from a file ,what flow of system calls gets executed

devkpict · 12-03-2007, 01:47 AM

While ,working with VI on my suse machine,I found that VI actually,
deletes the original file and creates all new file,with the same name,
both files have different inodes.

So iwant to figure out how he do it,What systemcalls get executed in the kernel.

druuna · 12-03-2007, 04:24 AM

Hi,

You can use strace to follow what vi is doing. Something like: strace vi infile 2>strace.out. strace.out holds all the system calls and signals.

Depending on how vim is configured (we are talking about vim, not vi I hope) the infile is unlinked or moved. The latter happens when set backup and set bex=.bak are set in the vimrc file (local or global).

Hope this helps.

devkpict · 12-03-2007, 11:36 PM

Quote:

Originally Posted by druuna

Hi,

You can use strace to follow what vi is doing. Something like: strace vi infile 2>strace.out. strace.out holds all the system calls and signals.

Depending on how vim is configured (we are talking about vim, not vi I hope) the infile is unlinked or moved. The latter happens when set backup and set bex=.bak are set in the vimrc file (local or global).

Hope this helps.

Thanks a lot,

Can we find what calls get executed at filesystem level.
i.e ext3

druuna · 12-04-2007, 07:54 AM

Hi,

Quote:

Originally Posted by devkpict

Thanks a lot,

You're welcome.

Quote:

Can we find what calls get executed at filesystem level.
i.e ext3

I don't think I understand the question. A 'normal' program doesn't (have to/ want to) know what FS it runs on, FS related stuff isn't taken care of by the 'normal' program.

You can however see in the strace output which files and dirs are called/written by vi.

Hope this helps.