Remove lines with no visible characters when reading a file

Question

Reading the official manual, if I want to skip empty line in a txt file, I just need to call the function file() with FILE_SKIP_EMPTY_LINES. I wrote:

$fileArray = file($uploadDirectory . $tracklistFile_name, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);

but it also shows empty lines. So, in a text like this :

// START OF THE DOCUMENT
aaa
bbb

ccc
ddd

// END OF THE DOCUMENT

In fact sizeof($fileArray) is 6 : it adds the empty lines between bbb and ccc, and the last one. Why?

Answer 1

There are a load of ways you could clean up the array but I like this one:

$fileArray = array_values(array_filter($fileArray, "trim"));

Answer 2

FILE_SKIP_EMPTY_LINES really only skips empty lines. If you have spaces or tabs or other whitespace in it, file() will not consider it an empty line.

It doesn't do a trim before checking, it looks if $line=="\n" and only then considers it an empty line.

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As alternative you could use:

$file = array_filter(array_map("trim", file("text.txt")), "strlen");