Print text between tags (inclusive) if certain text is found

Question

I've got a task to extract data from several Apache servers. The task is to print out:

<Directory ...>
  ...
</Directory>

where +ExecCGI is located within. Let me give an example to illustrate. Assume that the Apache configuration file has numerous Directory sections as indicated below:

<Directory /var/www/site1/htdocs>
  Options +ExecCGI
  ...
  ...
</Directory>
...
...
...
<Directory /var/www/site1/Promo>
  Options -ExecCGI
  ...
  ...
</Directory>

From above, I would only like to get the following output:

<Directory /var/www/site1/htdocs>
  Options +ExecCGI
  ...
  ...
</Directory>

I've searched the forums and have found posts where people have asked questions on how to print out a whole section between tags (I know how to do that), or to change certain text when found (again, I know how to do that).

I will be changing the +ExecCGI to -ExecCGI, but the changes need to go through a review process and hence this question so that I can pull this data out.

Answer 1

perl -l -0777 -ne 'for (m{<Directory.*?</Directory>}gs) {print if /\+ExecCGI/}'

Or with GNU grep:

grep -zPo '(?s)<Directory(?:.(?!</Directory))*?\+ExecCGI.*?</Directory>'

Answer 2

You could probably also use awk

awk 'BEGIN{RS="</Directory>\n"; ORS=RS} /\+ExecCGI/ {print}' file

Answer 3

If you can use perl, here is a solution:

$ perl -nle '
    if (/<Directory/) {
        $flag = 1;
    }
    push @a, $_ if $flag;
    if (/<\/Directory/) {
        $flag = 0;
        if (grep {$_ =~ /\+ExecCGI/} @a) {
            push @f, @a;
        }
        @a = ();
     }
END {
    print join "\n", @f;
}' file
<Directory /var/www/site1/htdocs>
  Options +ExecCGI
  ...
  ...
</Directory>

Explanation

• Each time we see <Directory, we set $flag = 1.
• If $flag is true (1 means true in boolean context), we push current entry to array @a.
• If we see </Directory, meaning we complete the block, we check if block contains +ExecCGI string grep {$_ =~ /\+ExecCGI/, then we push @a to @f.
• Set @a to empty array to process another block.

Answer 4

Here's an example in Bash (You should be able to do something similar in pretty much any language):

$ cat test.sh
#!/bin/bash

DIR=0
BLOCK=''
while read line
do
    if [ $DIR -eq 0 ] ; then
        if [[ $(echo $line | grep -i '<Directory') ]] ; then
            DIR=1
            BLOCK="$line"
        fi
    else
        BLOCK="$BLOCK\n$line"
        if [[ $(echo $line | grep -i '</Directory') ]] ; then
            if [[ $(echo $BLOCK | grep -i 'Options.*+ExecCGI') ]] ; then
                echo -e $BLOCK
            fi
            DIR=0
            BLOCK=""
        fi
    fi
done

Basically, we're just saving the block as we go along and then grepping it to see if it's got our pattern in it.

It's very simple, and is likely to have problems with some edge cases (if your config file has \ in it it might confuse echo -e for example), but you could expand the basic idea to deal with them.

Example in use:

$ cat test.conf
<Directory /var/www/site1/htdocs>
  Options +ExecCGI
  1
  2
</Directory>
3
4
5
<Directory /var/www/site1/Promo>
  Options -ExecCGI
  6
  7
</Directory>
<Directory /var/www/site1/htdocs>
  Options -Whatever +ExecCGI
  8
  9
</Directory>

$ cat test.conf | bash test.sh
<Directory /var/www/site1/htdocs>
Options +ExecCGI
1
2
</Directory>
<Directory /var/www/site1/htdocs>
Options -Whatever +ExecCGI
8
9
</Directory>