substitution in files

[Kelicula]

I am trying to open a file, and search for a srting. Once found I want to substitute it for something else and acually change the file.

ie) File named "stuff.txt" contains:

Hello I am Kelly
Hello I am David
Hello I am mark
 

I want to find David and change it to Josh.

This is how I am trying to do it, but it doesn't work.

open (FIL, "+<stuff.txt") or die "$!";
 
foreach $line (<FIL>){
 
if($line =~ m/David/){
$line =~ s/David/Josh/;
}
print $line;
}
 

What am I doing wrong?
I tried opening the file with ">>" and "+>>", to no avail.

???

[Kelicula]

I have solved this problem.
I load the lines into an array and then replace the line that matches.
ie)

open (INFO, "<stuff.txt") or die "$!";
 
@w =<INFO>;
close (INFO);
 
foreach $i (@w){
if ($i =~ m/David/){
$i =~ s/David/Josh/;
}
}

Now what I need is a way to disearn if it has been 24 hours since the last entry???


whatever...

I know it's too complicated to post here.

[miller]

Instead of loading the entire file into memory, I suggest that you take advantage of Tie::File for editing a file.

perlfaq5 - How do I change one line in a file/delete a line in a file/insert a line in the middle of a file/append to the beginning of a file?

- Miller

[Kelicula]

Thanks! because the file in question is going to get pretty big.
I am creating a survey for people to vote on a band. But the owner (my boss) wants people to be able to vote every 24 hrs. So my next challange is to be able to see if the time is greater than or less than 24 hrs from the last time they voted. (assuming the same ip address has voted before)
This has stopped me in my tracks.... :0 wft?
How in the world am I gonna do that? the date is formatted to a string and a number...
here's the page:
http://www.liveaudiomag.com/survey.shtml

right now all it does is display the file that I append to. I'm in the process of searching for ip and replacing line if found and greater than 24 hours ago. But wft? How am I going to be able to tell if they voted greater than 24 hours ago?


any help is greatly appreciated!!

[KevinADC]

when a person votes store the time they voted in epoch seconds using the time function:

$voted = time;

store that along with any other information you are already storing. Then check to see if the time is less than 24 hours. 24 hours would need to be broken down into seconds:

60x60x24=86400

so:

if ( $time+86400 < time) {
   less than 24 hours has passed
} 

where $time is the time you stored previously

[Kelicula]

KevinADC, you are truly brilliant!
Thanks, it works fine.
I am acually going to be able to have this thing running by the end of the weekend.
The Tie::File was a great help too.

Much Thanks!

[Kelicula]

I noticed in the Tie file page it mentions that concurrent access to files is inappropriate.

What would happen if several people were voting at the same time?

[KevinADC]

Look for "flock" in the Tie::File documentation. Thats about all you can do with a text file.