LJ Archive

UpFront

Tech Tip

Rich Lundeen

Issue #178, February 2009

Use SSH to Create an HTTP Proxy

SOCKS is built in to OpenSSH, so it's a trivial matter to set up a local SOCKS proxy with the -D flag. For example:

$ ssh -D 12345 myuser@remote_ssh_server

will open up the port 12345 on your local machine as a SOCKS proxy so all your HTTP traffic can be specified to go through the SSH tunnel and out remote_ssh_server on the other end. Your proxy server is now set up.

Next, set up your browser to use the proxy server. Most browsers include proxy support. For Firefox 3, go to Edit→Preferences→Advanced→Network→Settings, and specify that you want to use a Manual Proxy, localhost, port 12345, and SOCKS v5 (although OpenSSH supports both versions 4 and 5).

Now your browser is using a secure tunnel to your remote SSH server.

Tech Tip

Erik Falor

Issue #178, February 2009

Access the X Window System Clipboard from the Command Line with xclip

Ever selected text from your terminal so you could paste it into an X application? Drop the mouse and use xclip instead. Using xclip, you simply can pipe the contents that you want to clip directly into xclip:

$ lspci | xclip

Then, go to your X application and paste the captured output into the application. xclip also lets you “paste” selected text into the terminal. Just use the -o switch to output the highlighted text from the active selection:

$ xclip -o

xclip can be found at sourceforge.net/projects/xclip.

Tech Tip

Janos Gyerik

Issue #178, February 2009

Slice and Dice PDF

Using poppler-tools and psutils, you can extract a range of pages from a larger PDF file. For example, if you want to extract pages 11–14 of the PDF file afile.pdf, you could use the following command:

$ pdftops afile.pdf - | psselect -p11-14 | ps2pdf - file-p11-14.pdf

The pdftops command converts the PDF file to PostScript; the psselect command selects the relevant pages from the PostScript, and the ps2pdf command converts the selected PostScript into a new PDF file.

LJ Archive