[wellylug] Is there a good way to....

[Tony Booth]

Enkidu wrote:

> Is there a good way to drop lines from a file or do I have to do
something like
> (pseudo-code) ....
> 
> Open Output
> 	Open Input
> 	Read While Input
> 		If Record is a Match
> 			Then Write Output
> 			Else Nothing
> 	End Read
> 	Close Input
> Close Output
> 
> Cheers,

Well, I only have access to a Windows machine right now, so I haven't
tested this, but you could try:

sed -e '/RE!/s/(.*)/\1/g' filename

Where:

* RE is a regular expression to match (as in your 'Record is a Match'
pseudo-code) 
* The exclamation mark _should_ negate the RE, so that only lines not
matching are picked up.  This isn't totally clear from the
documentation, but I hope it will work.
* (.*) is the line from the file (you might need backslashes before each
bracket)
* \1 means to replace the line with the the (.*) text (i.e. take the
whole line and just print it out)

Best of luck.