How to remove a tagged block of text in a file?

How can I remove all instances of tagged blocks of text in a file with sed, grep, or another program?

If I have a file which contains:

random
text
// START TEXT
internal
text
// END TEXT
more
random
// START TEXT
asdf
// END TEXT
text

how can I remove all blocks of text within the start/end lines, produce the following?

random
text
more
random
text

Solution 1:

sed '\:// START TEXT:,\:// END TEXT:d' file

Solution 2:

The proper way to do this in Perl is with Perl's flip-flop operator

perl -ne'print unless m{^// START TEXT}..m{^// END TEXT}'

x..y in Perl evaluates to true starting with x is true, and ending when y is true. The m{} is another way to write a regular expression match so we don't have to go crazy backslashing all your forward slashes.

Solution 3:

#!/usr/bin/nawk -f
BEGIN {
startblock="^/\/\ START TEXT"
endblock="^/\/\ END TEXT"
}
{
        if(! match($0,startblock)) {
                { print }
        }
        else    {
                while ( !match($0,endblock )) {
                        getline;
                }
        }

}

./removeblocks < sometextfile >anothertextfile

Solution 4:

Perl:

perl -ne '$t=1 if /^\/\/ START TEXT/; print if !$t; $t=0 if /^\/\/ END TEXT/' < sometextfile >anothertextfile