Opens the current folder in Finder in Mac OSX Terminal
Answer:
Assume you are currently in folder /tmp/ in Terminal, and you want open this folder in Finder, you can type the following command:
# cd /tmp/
# open .Apr 092009
Linux Ask!
Apr 072009
Get user IP using PHP
Answer:
The following function is extracted from the popular phpMyAdmin, so why write it yourself?
function PMA_getIp()
{
global $REMOTE_ADDR;
global $HTTP_X_FORWARDED_FOR, $HTTP_X_FORWARDED, $HTTP_FORWARDED_FOR, $HTTP_FORWARDED;
global $HTTP_VIA, $HTTP_X_COMING_FROM, $HTTP_COMING_FROM;
// Get some server/environment variables values
if (empty($REMOTE_ADDR) && PMA_getenv('REMOTE_ADDR')) {
$REMOTE_ADDR = PMA_getenv('REMOTE_ADDR');
}
if (empty($HTTP_X_FORWARDED_FOR) && PMA_getenv('HTTP_X_FORWARDED_FOR')) {
$HTTP_X_FORWARDED_FOR = PMA_getenv('HTTP_X_FORWARDED_FOR');
}
if (empty($HTTP_X_FORWARDED) && PMA_getenv('HTTP_X_FORWARDED')) {
$HTTP_X_FORWARDED = PMA_getenv('HTTP_X_FORWARDED');
}
if (empty($HTTP_FORWARDED_FOR) && PMA_getenv('HTTP_FORWARDED_FOR')) {
$HTTP_FORWARDED_FOR = PMA_getenv('HTTP_FORWARDED_FOR');
}
if (empty($HTTP_FORWARDED) && PMA_getenv('HTTP_FORWARDED')) {
$HTTP_FORWARDED = PMA_getenv('HTTP_FORWARDED');
}
if (empty($HTTP_VIA) && PMA_getenv('HTTP_VIA')) {
$HTTP_VIA = PMA_getenv('HTTP_VIA');
}
if (empty($HTTP_X_COMING_FROM) && PMA_getenv('HTTP_X_COMING_FROM')) {
$HTTP_X_COMING_FROM = PMA_getenv('HTTP_X_COMING_FROM');
}
if (empty($HTTP_COMING_FROM) && PMA_getenv('HTTP_COMING_FROM')) {
$HTTP_COMING_FROM = PMA_getenv('HTTP_COMING_FROM');
}
// Gets the default ip sent by the user
if (!empty($REMOTE_ADDR)) {
$direct_ip = $REMOTE_ADDR;
}
// Gets the proxy ip sent by the user
$proxy_ip = '';
if (!empty($HTTP_X_FORWARDED_FOR)) {
$proxy_ip = $HTTP_X_FORWARDED_FOR;
} elseif (!empty($HTTP_X_FORWARDED)) {
$proxy_ip = $HTTP_X_FORWARDED;
} elseif (!empty($HTTP_FORWARDED_FOR)) {
$proxy_ip = $HTTP_FORWARDED_FOR;
} elseif (!empty($HTTP_FORWARDED)) {
$proxy_ip = $HTTP_FORWARDED;
} elseif (!empty($HTTP_VIA)) {
$proxy_ip = $HTTP_VIA;
} elseif (!empty($HTTP_X_COMING_FROM)) {
$proxy_ip = $HTTP_X_COMING_FROM;
} elseif (!empty($HTTP_COMING_FROM)) {
$proxy_ip = $HTTP_COMING_FROM;
} // end if... elseif...
// Returns the true IP if it has been found, else false
if (empty($proxy_ip)) {
// True IP without proxy
return $direct_ip;
} else {
$is_ip = preg_match('|^([0-9]{1,3}\.){3,3}[0-9]{1,3}|', $proxy_ip, $regs);
if ($is_ip && (count($regs) > 0)) {
// True IP behind a proxy
return $regs[0];
} else {
// Can't define IP: there is a proxy but we don't have
// information about the true IP
return false;
}
} // end if... else...
} // end of the 'PMA_getIp()' function
Apr 022009
How to enable / disable service during startup in Fedora?
Answer:
Firstly, check if the service can be managed by chkconfig, e.g. Apache httpd
# chkconfig --list httpd
httpd 0:off 1:off 2:off 3:on 4:on 5:on 6:off
To disable the service during normal startup, use
# chkconfig httpd off
To re-enable it, use
# chkconfig httpd on --level 3,4,5
Mar 262009
How to replace multiple strings using sed?
Answer:
If you have multiple strings to replace, you can either using the "-e" option in sed, e.g.
sed -e 's/a/A/' -e 's/b/B/' < old.txt > new.txt
or, you can use a sed script file to store all the replace conditions
e.g. vi replace.sed
s/a/A/g
s/b/B/g
s/c/C/g
and execute like
sed -f replace.sed < old.txt > new.txt
Mar 142009
Install APC for PHP on Ubuntu
Answer:
APC is a very fast byte-code caching module for PHP. (It will become part of PHP6 in the future). By installing it, the performance of your PHP codes can be speed up by 200-300%.
To install it under Ubuntu,
# sudo apt-get install php-apc
Then restart Apache,
# sudo /etc/init.d/apache2 restart
