sed stops to output with -n option 1

[vakimova]

dear all,
the command
>sed s/m/x/g
works on my box OK. But adding '-n'
>sed -n s/m/x/
makes it to output blank lines even after those containing "m's"
How to understand this deviation from a tutorial predictions?

yours`
serguey

 

[feherke]

Hi

With -n [tt]sed[/tt] produce no default output. If you want it to write something, you must tell it, for example with the [tt]p[/tt] ( print ) command.

Feherke.

http://rootshell.be/~feherke/

 

[vakimova]

dear Feherke,

thank you for the info,
maybe I've knocked on a wrong tutorial.

yours`
serguey