Linux / Unix: sed Command Print Only Matching Lines

Posted on in Categories last updated October 19, 2012

I see many examples and man pages on how to do operations like search-and-replace using sed. But, I want to match a given string or a regular pattern expression and display on the screen. How do I print lines with matching pattern using sed command only under Unix like operating systems?

Linux: warning: CUPSEXT could not be loaded. Please check HPLIP installation.

Posted on in Categories , last updated September 29, 2012

I‘m trying to install latest version of Hewlett-Packard’s Linux Imaging and Printing software (HPLIP) for my office jet printer. In order to install latest version of HPLIP I removed the hplip-gui, hplip, hplip-cups, hplip-data, hpijs, and hpijs-ppds Debian Linux packages However, I’m getting the following error:

Debian warning: CUPSEXT could not be loaded. Please check HPLIP installation.

How do I fix this error while installing hplip-3.12.9.run under Debian Linux 6.0.5 amd64 bit?

awk: warning: escape sequence '\<' treated as plain '>'

Posted on in Categories last updated September 29, 2012

I‘m trying to match words using GNU awk command and getting the following error:

echo 'foo bar this that blah' | awk '{gsub("\<regex-word\>", "NEW-WORD");print}'

But getting the following warning on screen and it is not working:
awk: warning: escape sequence `\<' treated as plain `<' awk: warning: escape sequence `\>' treated as plain `>'

How do I fix this problem under Unix like operating systems?