function call:
string trim ( string $str [, string $charlist ])

description:
This function returns a string with whitespace stripped from the beginning and end of $str. Without the second parameter, trim() will strip these characters:

• " " (ASCII 32 (0x20)), an ordinary space.
• "\t" (ASCII 9 (0x09)), a tab.
• "\n" (ASCII 10 (0x0A)), a new line (line feed).
• "\r" (ASCII 13 (0x0D)), a carriage return.
• "\0" (ASCII 0 (0x00)), the NUL-byte.
• "\x0B" (ASCII 11 (0x0B)), a vertical tab.

test trim online:

$str

$charlist