php通用函数--html--时间--文件大小--生成随机数

function format_html($str) {
return htmlentities($str, ENT_COMPAT, 'UTF-8');
}

function format_ago($time, $ago = false) {
$minute = 60;
$hour = $minute * 60;
$day = $hour * 24;

$when = $time;

if ($when >= 0)
$suffix = 'ago';
else {
$when = -$when;
$suffix = 'in the future';
}

if ($when > $day) {
$when = round($when / $day);
$what = 'day';
} else if ($when > $hour) {
$when = round($when / $hour);
$what = 'hour';
} else if ($when > $minute) {
$when = round($when / $minute);
$what = 'minute';
} else {
$what = 'second';
}

if ($when != 1) $what .= 's';

if ($ago) {
return "$when $what $suffix";
} else {
return "$when $what";
}
}

function format_size($size) {
$sizes = array('B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB');

if ($size == 0) {
return '0 B';
} else {
return round($size / pow(1024, ($i = floor(log($size, 1024)))), 1).' '.$sizes[$i];
}
}

function str_rand($length) {
$r = '';

for (; $length > 0; --$length) {
$r .= chr(rand(32, 126)); // 32 - 126 is the printable ascii range
}

return $r;
}