Nrthugu

I am trying to extract lines from a file where the end string is different from the begin string

I have the following input file in format:

<item_id>6</item_id>

  <info1>abc</info1>

  <info2>123</info2>

<item_id>6</item_id>

  <info1>def</info1>

  <info2>456</info2>

<item_id>6</item_id>

  <info1>ghi</info1>

  <info2>789</info2>

<item_id>9</item_id> 

  <info1>jkl</info1>

  <info2>012</info2>

<item_id>9</item_id>

  <info1>mno</info1>

  <info2>345</info2>

I want to extract from "6" until "9" (9 being a random number)

Begin is <item_id>6<item_id>

End is <item_id>X<item_id> X being anything but 6

Expected result:

<item_id>6</item_id>

  <info1>abc</info1>

  <info2>123</info2>

<item_id>6</item_id>

  <info1>def</info1>

  <info2>456</info2>

<item_id>6</item_id>

  <info1>ghi</info1>

  <info2>789</info2>

I tried:

sed -n "/<item_id>6</item_id>/,/<item_id>!6</item_id>/p" input.file > output.6

sed -n "/<item_id>6</item_id>/,/<item_id>!6</item_id>/p" input.file > output.6

sed -n "/<item_id>6</item_id>/,/<item_id>{!6}</item_id>/p" input.file > output.6

sed -n "/<item_id>6</item_id>/,/<item_id>(6)@!.</item_id>/p" input.file > output.6

sed -n "/<item_id>6</item_id>/,/<item_id>! 6</item_id>/p" input.file > output.6

Maybe this GNU sed script will work for you:

sed '/<item_id>6</item_id>/{:1;n;/<item_id>[^6]</item_id>/{Q};b1};d' file

Keep deleting d lines until a 6 line is found, then keep in the internal loop b1 printing each line until a not 6 ([^6]) line is found, at which time the script is Quit.

Understand that this works only for one character numbers (the 6 or the 9).

It gets quite messy to get it to work with any number (GNU):

sed -e 'h;s,<item_id>([0-9]*)</item_id>,1,;/^6$/!d;/^6$/{g;:1;h;s,<item_id>([0-9]*)</item_id>,1,;t2;:3;g;n;b1};d;b;:2;/^6$/!Q;b3' file

Using a couple of vars makes it a bit better, but not that much

reg='<item_id>([0-9]*)</item_id>'

item='6'



sed -e "h;s,$reg,1,;/^$item$/!d;/^$item$/{g;:1;h;s,$reg,1,;t2;:3;g;n;b1};d;b;:2;/^$item$/!Q;b3" file

And a POSIXfyed one looks like gibberish:

sed -ne 'h;s,<item_id>([0-9]*)</item_id>,1,;/^6$/!d;/^6$/{g;:1;h;s,<item_id>([0-9]*)</item_id>,1,;t2;:3;g;p;n;b1;};d;b;:2;/^6$/!q;b3' file

Only this extended code might(?) be more readable:

reg='<item_id>([0-9]*)</item_id>'

item='6'



sed -ne 'h;                 # hold copy of line being processed.

         s,'"$reg"',1,;    # extract included number.

         /^'"$item"'$/!d;   # Not the correct number?: get next line.

         /^'"$item"'$/{

         g;                 # restore line from hold buffer.

         :1

         h;                 # store successive lines in hold buffer.

         s,'"$reg"',1,;    # extract the number (again).

         t2

         :3

         g;                 # restore the line back from hold buffer.

         p;                 # print the line.

         n;                 # go to process next line.

         b1

         };                 # end of loop.

         d;                 # avoid printing this last line.

         q;                 # quit the sed script.

         :2

         /^'"$item"'$/!q;   # Test if the number is the one selected.

         b3

        ' file

Maybe you should use some other language or tool.

Assuming this is a well-formed XML document, the following uses XMLStarlet to pick out the info_id nodes whose values are 6, and then the immediately following sibling info1 and info2 nodes:

$ xmlstarlet sel -t -m '//item_id[. = 6]' 

    -c . -nl 

    -c './following-sibling::info1[1]' -nl 

    -c './following-sibling::info2[1]' -nl file.xml

<item_id>6</item_id>

<info1>abc</info1>

<info2>123</info2>

<item_id>6</item_id>

<info1>def</info1>

<info2>456</info2>

<item_id>6</item_id>

<info1>ghi</info1>

<info2>789</info2>

Alternatively, to ignore what the following nodes are called:

xmlstarlet sel -t -m '//item_id[. = 6]' 

    -c . -nl 

    -c './following-sibling::*[1]' -nl 

    -c './following-sibling::*[2]' -nl file.xml