Text file as single string in PHP code

Question

my text file is like this:

atagatatagatagtacataacta\n
actatgctgtctgctacgtccgta\n
ctgatagctgctcgctactacgat\n
gtcatgatctgatctacgatcaga\n

I need this file in single string or in single line in both same and reverese order like this:

atagatatagatagtacataactaactatgctgtctgctacgtccgtactgatagctgctcgctactacgatgtcatgatctgatctacgatcaga

and "reverese" (for which I didn't write code because I need help ).
I am using:

<?php
    $re = "/[AG]?[AT][AT]GAGG[ATC]GC[GA]?[ATGC]/"; 

    $str = file_get_contents("filename.txt");
    trim($str);

    preg_match($re, $str, $matches);
    print_r($matches);
?>

Why do you use preg_match? Just remove the newline characters. — user4035
– user4035, Commented Mar 10, 2015 at 6:56

Mario A · Accepted Answer · 2015-03-10 07:05:39Z

1

You can remove spaces and newlines using preg_replace, and you can reverse a string using strrev.

$yourString = "atagatatagatagtacataacta\n actatgctgtctgctacgtccgta\n ctgatagctgctcgctactacgat\n gtcatgatctgatctacgatcaga\n";    
$stringWithoutSpaces = preg_replace("/\s+/", "", $yourString);
$stringReversed = strrev($stringWithoutSpaces);
echo $stringReversed;

http://php.net/manual/de/function.preg-replace.php

http://php.net/manual/en/function.strrev.php

Explanation: With preg_replace you replace any character in $yourString with an empty string "" that matches the search pattern "/\s+/". The \s in the search pattern stands for any whitespace character (tab, linefeed, carriage return, space, formfeed), the + is there to match also multiple whitespace characters, not just one.

edited Mar 10, 2015 at 7:05

answered Mar 10, 2015 at 6:59

Mario A

3,3711 gold badge20 silver badges25 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Mario A Over a year ago

By the way, in your example you use /n as newlines, which will not work, you have to use \n. I made an update in my example to correct this.

Collectives™ on Stack Overflow

Text file as single string in PHP code

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related