Keby niekoho zaujímalo, že prečo je to tak, tak je to preto tak, lebo:
Kód:
<?php
$meno = "Janko";
echo "Volam sa $meno"; // vypise text "volam sa Janko"
echo 'Volam sa $meno'; // vypise text "volam sa $meno"
?>
Čiže, text v apostrofoch neinterpretuje špeciálne znaky ako špeciálne znaky, ale ako obyčajné znaky. Preto v tvojom prípade nespraví riadne odriadkovanie pomocou \r\n ale iba ich vypíše ako text. To samozrejme odporuje formátu protokolu a už je to celé zle.
A. S. Tanenbaum píše:
The terms LF, MF, and HF refer to low, medium, and high frequency, respectively. Clearly, when the names were assigned, nobody expected to go above 10 MHz, so the higher bands were later named the Very, Ultra, Super, Extremely, and Tremendously High Frequency bands. Beyond that there are no names, but Incredibly, Astonishingly, and Prodigiously high frequency (IHF, AHF, and PHF) would sound nice.
