If I have a text file that has a dozen lines/rows, how do I select a specific row as an array?

For example the following | delimited file:

1234|abc1234|def1234
1235|abc1235|def1235
1236|abc1236|def1236
1237|abc1237|def1237
1238|abc1238|def1238

How would I select the line that starts with 1237, and echo column 3? I know the echo would look something like this: echo column [2], but I don't know how to select the row I want parsed into an array.

Can someone point me in the right direction?

You need 2 things:
1) iterate through lines
2) convert the line to an array

For the point 1, use fgets()
http://www.php.net/manual/en/function.fgets.php
For the point 2, use explode()
http://www.php.net/manual/en/function.explode.php

PHP Code:

$h=fopen("file.txt",r);
$run=true;
while( (false!=$buffer=fgets($h)) && ($run==true) ){
  $ary=explode("|",$buffer);
  //... Test your condition here against $ary
  if($ary[0]=='1237'){
    echo "found it! ->{$ary[2]}\n";
    //To stop the file parsing
    $run=false;
  }
  else{
    echo "not found...\n";
  }
}
fclose($h); 


Just a side note, array indexes starts from 0, so the first field is 0, and your data field is nbr 2.

Hi,
I am prefer to use file function.

PHP Code:

<?php
// looking for 1237 line

$file = file("data.txt");
foreach($file as $val) {
list($id, $first, $second) = explode("|", $val);
   if($id == "1237") {
      echo "Id = " . $id . "<br />First data = " . $first . "<br />Second data = " . $second;
      break;  // stop the loop
   }
}
?>

Shivaji

Which option is better under heavy server load? fopen or file?

Depend your file size.
Fgets parse the file line by line.
file() fetch all the file in memory.

It's the only significant difference, I'd say.
But on a 1+Mo file, it can be noticeable.

Now that I figured that out, I have another problem. In column [0], the first row, I have a number. How do I check for the largest number in the column, and set a variable to be the largest number +1?

In that case, you don't exit the parsing of the file when you look for your line, and you keep the greatest value in a variable.
But why do you bother with a text file?
For what I see, a database would be way more suited.

PHP Code:

$h=fopen("file.txt",r);
$run=true;
$max=0;
while( (false!=$buffer=fgets($h)) && ($run==true) ){
  $ary=explode("|",$buffer);
  //... Test your condition here against $ary
  if($ary[0]=='1237'){
    echo "found it! ->{$ary[2]}\n";
    //To stop the file parsing
    //$run=false;
  }
  else{
    echo "not found...\n";
  }
  if($max<$ary[0]){
    //$max will hold the biggest value from your file after that.
    $max=$ary[0];
  }
}
fclose($h); 


Are you afraid of databases or your hoster does not offer mysql on free plan? Considering your current needs you will have to migrate to database anyway.

No, this is just an attempt on my part to learn some basics of using text files. My host does provide mysql.

I am just trying to learn something new.