Obtain first line of a string in PHP

问题

In PHP 5.3 there is a nice function that seems to do what I want:

strstr(input,"\n",true)

Unfortunately, the server runs PHP 5.2.17 and the optional third parameter of strstr is not available. Is there a way to achieve this in previous versions in one line?

回答1:

here you go

$str = strtok($input, "\n");

strtok() Documentation

回答2:

It's late but you could use explode.

<?php
$lines=explode("\n", $string);
echo $lines['0'];
?>

回答3:

$first_line = substr($fulltext, 0, strpos($fulltext, "\n"));

or something thereabouts would do the trick. Ugly, but workable.

回答4:

try

substr( input, 0, strpos( input, "\n" ) )

回答5:

echo str_replace(strstr($input, '\n'),'',$input);

回答6:

try this:

substr($text, 0, strpos($text, chr(10))

回答7:

list($line_1, $remaining) = explode("\n", $input, 2);

Makes it easy to get the top line and the content left behind if you wanted to repeat the operation. Otherwise use substr as suggested.

回答8:

not dependent from type of linebreak symbol.

(($pos=strpos($text,"\n"))!==false) || ($pos=strpos($text,"\r"));

$firstline = substr($text,0,(int)$pos);

$firstline now contain first line from text or empty string, if no break symbols found (or break symbol is a first symbol in text).

回答9:

You can use strpos combined with substr. First you find the position where the character is located and then you return that part of the string.

$pos = strpos(input, "\n");

if ($pos !== false) {
echo substr($input, 0, $pos);
} else {
echo 'String not found';
}

Is this what you want ?

l.e. Didn't notice the one line restriction, so this is not applicable the way it is. You can combine the two functions in just one line as others suggested or you can create a custom function that will be called in one line of code, as wanted. Your choice.

回答10:

Many times string manipulation will face vars that start with a blank line, so don't forget to evaluate if you really want consider white lines at first and end of string, or trim it. Also, to avoid OS mistakes, use PHP_EOL used to find the newline character in a cross-platform-compatible way (When do I use the PHP constant "PHP_EOL"?).

$lines = explode(PHP_EOL, trim($string));
echo $lines[0];

回答11:

A quick way to get first n lines of a string, as a string, while keeping the line breaks.

Example 6 first lines of $multilinetxt

echo join("\n",array_splice(explode("\n", $multilinetxt),0,6));

Can be quickly adapted to catch a particular block of text, example from line 10 to 13:

echo join("\n",array_splice(explode("\n", $multilinetxt),9,12)); 

来源：https://stackoverflow.com/questions/9097682/obtain-first-line-of-a-string-in-php