Tab delimited txt file PHP selecting from array - php

Question

I am trying to select columns in my tab separated document.
The problem i am having is i get this error....
Notice: Undefined offset: 1 in E:\xampp\htdocs\qrcode\tab.php on line 11
Notice: Undefined offset: 2 in E:\xampp\htdocs\qrcode\tab.php on line 12
Notice: Undefined offset: 3 in E:\xampp\htdocs\qrcode\tab.php on line 13
Code:
$file = "t_rac.txt";// Your Temp Uploaded file
$handle = fopen($file, "r"); // Make all conditions to avoid errors
$read = file_get_contents($file); //read
$lines = explode("\n", $read);//get
$i= 0;//initialize
$o=1;
foreach($lines as $key => $value){
$cols[$i] = explode("\t", $value);
$list=($cols[$o++][1]);
$list.=($cols[$o++][6]);
$list.=($cols[$o++][7]);
$i++;
}
echo $list;

Answer 1

Updated code off of data this works for ya.
I skip the 1st line, and make sure the column is not out of bounds before adding item.
$lines = explode("\n", $read); //get
$i = 0;//initialize
$list = "";
foreach($lines as $value)
{
if($i != 0)
{
$cols[$i] = explode("\t", $value);
if(isset($cols[$i][1]))
$list.=($cols[$i][1]);
if(isset($cols[$i][6]))
$list.=($cols[$i][6]);
if(isset($cols[$i][7]))
$list.=($cols[$i][7]);
$list.= "<br />";
}
$i++;
}
echo $list;

Answer 2

Your array keys are totally wrong:
$list=($cols[$o++][1]);
^^^^
That changes $o every time you use it. So on your first iteration of the loop, you're doing:
$list=($cols[1][1]);
$list.=($cols[2][6]);
$list.=($cols[3][7]);
Note that $o is now 4... On your second iteration you're doing
$list=($cols[4][1]);
$list.=($cols[5][6]);
$list.=($cols[6][7]);
and $o is 7 at the end of the iteration, etc... If you have 100 rows to process, $o will end up being 301, and you do NOT have that many columns in your $cols array.

Answer 3

May I suggest using the fgetcsv PHP function to parse character delimited files. There is no need to use explode.
Edit - I just read your other comment and understand now what you mean. Updated.
Edit - So you need to get columns 1, 6 and 7 from the same row then. Also added check for first row.
function getMeTheString($file) {
$str = "";
if (($handle = fopen($file, "r")) === FALSE) return;
$line = 0;
while (($cols = fgetcsv($handle, 1000, "\t")) !== FALSE) {
if ($line > 0) { // Ignore 1st line
$str .= $cols[1];
$str .= $cols[6];
$str .= $cols[7];
}
$line++;
}
return $str;
}
echo getMeTheString("t_rac.txt");

Answer 4

Thank you so much everyone! Here is the working code! Works like a charm #Demodave Thank you!!
<?php
$file = "t_rac.txt";// Your Temp Uploaded file
$handle = fopen($file, "r"); // Make all conditions to avoid errors
$read = file_get_contents($file); //read
$lines = explode("\n", $read); //get
$i = 0;//initialize
$list = "";
foreach($lines as $value)
{
if($i != 0)
{
$cols[$i] = explode("\t", $value);
if(isset($cols[$i][2]))
$list.=($cols[$i][2]);
$list.= "--";
if(isset($cols[$i][3]))
$list.=($cols[$i][3]);
$list.= "--";
if(isset($cols[$i][4]))
$list.=($cols[$i][4]);
$list.= "--";
if(isset($cols[$i][6]))
$list.=($cols[$i][6]);
$list.= "--";
if(isset($cols[$i][7]))
$list.=($cols[$i][7]);
$list.= "--";
if(isset($cols[$i][23]))
$list.=($cols[$i][23]);
$list.= "<br />";
}
$i++;
}
echo $list;
?>