Suppose we are asked to install a Debian based flavor on an old laptop or PC but we are unsure about the type of disk that is used. One solution could be the use of a bootable live usb to check performance and gather system specifications prior to installation. This post will walk us through helpf...

7. Working with strings

7.1 Case insensitive matching

The i or I as a flag for the substitution command implies case-insensitive substitution. Here, the pattern is lowercase and the s command will substitute to upper case ignoring case.

sed  -n 's/victor hugo/VICTOR HUGO/pi' books.log

Th...