Modify A Program

UNIX for Advanced & Expert Users
1

hi all,

I'm sorry for my english.

I have this problem:
I and my collegues can modify the same file at the same time.
Is it possible delete this problem?

The editor is VI.

thanks.

2

Good Morning,

this is not a problem, this is a feature :slight_smile:

No, of course you can edit the same file X times at the same time, but when you are not the first one, who edit this file, you will usually get a message, that a temporary file exists.
So you have to accept it and go on with modification, bad idea, or you you have to leave.

Maybe it's a better idea to work locally on your own file, and after editing, you sync your file with the original file, look at cvs for example, its very powerfull.

regards
Alex

3

Hi,

a solition might be ci/co, standard on HP-ux and Sun (and maybe more). It's a horrible apllication but it keeps you from these problems.

Of course you can write a script that does, the folowing ? :

#!/usr/local/bin/perl
# Script that creates lock-file

$file=$ARGV[0];
@last_f=split(/\//, $file );
@last_f=reverse @last_f;
$last_f = $last_f[0];

if ( -f "/tmp/${last_f}" ) {
print "Sorry, $last_f is still opened by someone else \n";
}
else {
`touch /tmp/${last_f}`;
$cmd = sprintf("/usr/bin/vi %s",$file);
$status = system($cmd);
`rm /tmp/$last_f`;
}

Regs David

4

just make sure not to run that script as root....someone could put a symbolic link where that /tmp lockfile is to point to /etc/nologin, or worse yet /dev/kmem. etc, etc.

5

i think mandatory locking would do what you want...
that forbid multi-access to one file...

chmod +l <file>

read the man page for better explanation...

greetings Pre�y