I move between three different network configurations with my powerbook in an average day. Two of these configurations have proxy servers and one does not. Mac OS X has really excellent network location support that lets me configure this stuff once so that switching locations is as simple as invoking QuickSilver, typing the first few letters of the network location and BAM.
Most applications automatically pick up the new proxy configuration
but some do not, like Firefox (which is one of three big reasons I
still use Safari). I do a lot of work from the command line with network
based tools such as
etc. None of these use the system proxy settings but most support
specifying a proxy server via the
I’ve searched high and low for a mechanism that would handle setting the
http_proxy variable based on my current network location but have come
up with nothing.
First, you need to create a file
/etc/http_proxy that specifies the
proxy servers for each Network Location you have setup in your Network
Preferences (If anyone can figure out how to get the proxy information
directly please let me know. I can get the current network location but
not information about it). The file might look something like this:
Work = http://proxy.example.com:80 Library = http://proxy.library.com:80
The keys are the names of your network locations and the values are in
Next, you’ll need to put the following script somewhere along your
proxy-config and give it a
chmod +x too.
#!/bin/bash # source this into your current to have the proxy # environment variables needed by many command line # apps setup correctly. # get the current network location name netloc=$(/usr/sbin/scselect 2>&1 | egrep '^ \* ' | \ sed 's:.*(\(.*\)):\1:') # find the proxy in /etc/http_proxy based on the # current location http_proxy=$(egrep "$netloc[ \t]*=" /etc/http_proxy | \ sed 's/.*=[ \t]*\(.*\)/\1/') if [ -n "$http_proxy" ]; then export http_proxy export HTTP_PROXY="$http_proxy" else unset http_proxy unset HTTP_PROXY fi # the rest of this is used for symlink commands bn=$(basename $0) if [ "$bn" != "proxy-config" ]; then dn=$(cd $(dirname $0); pwd) for p in $(echo $PATH | sed 's/:/ /g'); do [ "$p" != "$dn" ] && [ -x "$p/$bn" ] && exec "$p/$bn" "[email protected]" done fi
This script has two usage scenarios. You can source this into your
current shell to have the
http_proxy set correctly based on your
current network location:
$ . proxy-config $ echo $http_proxy http://proxy.example.com:80
Alternatively, you can create symlinks to the
using the names of commands that require
http_proxy and the script
will automatically set the variable and exec the real command.
Got that? No? Okay, let’s move on.
Pretend you have
/usr/bin/curl and you put the script from above at
/usr/local/bin/proxy-config. You can get
curl to use the approriate
proxy settings by doing something like this:
# mkdir /usr/local/proxybin # cd /usr/local/proxybin # ln -s ../bin/proxy-config curl # ls -l total 4 lrwxr-xr-x 1 root wheel 19 May 11 13:30 curl -> ../bin/proxy-config
As long as
/usr/local/proxybin is on your
curl will actuall call
then setup the proxy settings and exec
Now just create a symlink just like the one made for
curl for anything
else that requires proxy settings and enjoy network location support
from the command line.