Tag Archives: sed

SSH tunnels are a great tool to solve various problems with routing where a firewall does not allow to access a certain local network. They allow forwarding connections to a specified port on the server machine to a local or remote computer through an encrypted channel.

Although there are nice …

Sometimes it is useful to keep the header of an output of some command while grepping the same output for something else. In the example below, the column information is absent:

A solution without regular expressions

There are many ways for selecting columns in a delimited text. The easiest ones require GNU awk, cut and Perl. Let's consider the following file: