Remove a particular sub-string from string

Question

I have following text after reading a file:

06/16/2011 04:01:05 AM : Process Start
06/16/2011 04:01:05 AM : Creating File
06/16/2011 04:01:05 AM : Opening File
06/16/2011 04:01:05 AM : Writing Text
06/16/2011 04:01:05 AM : Closing File
06/16/2011 04:01:05 AM : Sending File in email
06/16/2011 04:01:05 AM : Process End

I want to remove date and time in the beginning of each line like this:

Process Start
Creating File
Opening File
Writing Text
Closing File
Sending File in email
Process End

How can we do this with string matching technique ?

Thanks

Split each line of string (using AM or PM as condition) into 2 parts and pick the second part — Predator
– Predator, Commented Jun 16, 2011 at 9:58

Kokos · Accepted Answer · 2011-06-16 10:08:48Z

5

One way to do this would be the following: (assuming the prefix is always the same length)

$output = '';
$tmp    = explode("\n",$input);

foreach($tmp as $t)
    $output .= substr($t,25)."\n";

echo $output;

First you explode the input into a variable by splitting it on every new line, and then for each line you remove the first 25 characters to create a new output.

http://codepad.org/ewuecNuU

edited Jun 16, 2011 at 10:08

answered Jun 16, 2011 at 9:57

Kokos

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Comments

IvanGL · Accepted Answer · 2011-06-16 09:56:27Z

2

Date and time have constant length in your file. Use substr function to cut off 25 symbols from start of each line.

answered Jun 16, 2011 at 9:56

IvanGL

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3 Comments

Student Over a year ago

How to get each line separately and process it ??

Kokos Over a year ago

@Student, if you look at my explanation I've provided code to do what IvanGL describes here.

IvanGL Over a year ago

use explode function: $lines = explode("\n", $text);

Miki · Accepted Answer · 2011-06-16 09:57:03Z

2

If all strings are prefixed with text of the same length, use substring. If not, use regular expression matching.

answered Jun 16, 2011 at 9:57

Miki

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Comments

Karolis · Accepted Answer · 2011-06-16 10:05:21Z

2

According to your example it seems that the best thing is to use substr() because the size of the prefix is always the same. But if you really need a matching technique it will look something like this:

$new_line = preg_replace('^/\d{2}\/\d{2}\/\d{4}\/ \d{2}:\d{2}:\d{2}\/ (?:AM|PM) : /', '', $line);

answered Jun 16, 2011 at 10:05

Karolis

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Stuck · Accepted Answer · 2011-06-16 10:04:25Z

1

echo preg_replace('/(.*): /', '', $input);

answered Jun 16, 2011 at 10:04

Stuck

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3 Comments

Student Over a year ago

It is good but it is not working correctly when there is another : in message after first :

Stuck Over a year ago

yes, but your question does not provide that information. Use karolis more verbose answere then.

Student Over a year ago

Yes. Therefore I up-voted you.. But my actual file contains extra :. Anyway Thanks...

questioner · Accepted Answer · 2011-06-16 10:12:58Z

1

$str = "text : to : remove :  text to keep";
$pos = strrpos($str, ":");
$str2 = substr($str, $pos+1);
echo $str2;

edit: changed strpos to strrpos, to find the last occurrence, as per comment below

edited Jun 16, 2011 at 10:12

answered Jun 16, 2011 at 10:05

questioner

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1 Comment

Kokos Over a year ago

This wouldn't work, there's : in the date as well, plus this would remove the ability to have : in the "text to keep".

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