Remove lines of text using a script

[glennzo]

I wonder if anyone can help me and at the same time teach me ... how to remove lines containing selected text from a text file using bash scripting. For example, if a text file contains the following lines, at random locations within the file and not necessarily one following the other:

PHP Code:

glenn the_linuxfan
mike the_linuxfan
john the_linuxfan 


How the h-e double hockey sticks is this accomplished? I've examined sed and awk, loops, arrays, etc. but I just-can't-get-it-right !!!!

Your kind suggestions will be immensely appreciated.

[sea]

Found a link to explain this task:
http://en.kioskea.net/faq/1451-sed-d...es-from-a-file
http://www.cyberciti.biz/faq/howto-l...l-blank-lines/

[DBelton]

you can delete the lines using grep.

Using your above examples:

cat oldfilename |  grep -Ev 'glenn the_linuxfan|mike the_linuxfan|john the_linuxfan' > newfilename

You can also have grep read a file with the "criteria" in it as well. Check grep out some more and see if it's what you need.

[jpollard]

Note, that delete will also delete any lines that CONTAIN the pattern matched.

This applies to lines that have more than the text, which you might want to keep. Judicious use of matching beginning of lines and end of lines would be needed then.

Oh, and you can shorten the command to "grep -Ev '....'<oldfilename >newfilename"
or even drop the input redirection.

[stevea]

Originally Posted by jpollard

Note, that delete will also delete any lines that CONTAIN the pattern matched.

Re-read the original problem statement in post #1 please. That IS what was requested.
You are confabulating exceptions unnecessarily.

Originally Posted by glennzo

... how to remove lines containing selected text [...]

Glenn wants to remove lines matching the pattern, not just exact whole line matches.

[RupertPupkin]

If you want to edit the file in place (and not save to a different file), you could use sed:

sed -i -e '/\(glenn the_linuxfan\|mike the_linuxfan\|john the_linuxfan\)/d' myfile.txt

[jpollard]

Originally Posted by stevea

Re-read the original problem statement in post #1 please. That IS what was requested.
You are confabulating exceptions unnecessarily.

Yes it was. All I was doing was noting what COULD be desired to ONLY remove those lines.

Not exceptions at all.

[glennzo]

Great solutions! I thank you all for your comments. I'll use Rupert's solution if the rest of you don't mind.

Step up to the virtual bar. I'm buying.