Shell script to extract particular content using find, xargs, and grep

Question

Hi everyone. Well i am new to linux shell and i can't understand any regexp :(

Here is my question: I have a directory called /var/visitors and under this directory, i have directories like a, b, c, d. In each of these directories, there is a file called list.xml and here is the content of list.xml belonging to /var/visitors/a directory:

<key>Name</key>
<string>Mr Jones</string>
<key>ID</key>
<string>51</string>
<key>Len</key>
<string>53151334</string>

what i want to do is to merge Name field with its corresponding string and merge ID field with its corresponding string.. I don't need other fields..

Name: Mr Jones
ID: 51
---
Name: Ms Maggie
ID: 502

Here is what i can write:

cd /var/visitors
find -name "list.xml" | xargs grep ?????

Well please help me :(( I am really stuck I need to write this asap :( Thanks for your attention.

Answer 1

Grep is not going to help you here, you are going to need to use something like sed or awk.

Answer 2

This is real dirty, but if you're sure they're in the format they're in, you could throw some perl together to parse it... something like

for (<STDIN>) {
  if (/<key>([^<]*)</) { print $1 . " : "; }
  if (/<string>([^<]*)</) { print $1 . "\n"; }
}

that may not be perfect, but close to accomplishing what you're looking for. I'm sure there is probably some perl module that will parse XML for you, too, but for such a non-complex schema, I think you'll be ok without it.

Answer 3

Assuming you have the file foo.bar containing the following text:

<key>Name</key>
<string>Mr Jones</string>
<key>ID</key>
<string>51</string>
<key>Len</key>
<string>53151334</string>

something like this will work:

$ awk -F '[<>]' '{if (FNR%2==1) {printf "%s: ",$3} else {print $3}}' foo.bar
Name: Mr Jones
ID: 51
Len: 53151334

If it's not entirely what you're wanting, shoe-horn it further to meet your specific requirements.

Answer 4

Not elegant, but this will work:

find -name "list.xml" | xargs cat | tr -d "\n" | sed 's/<\/string>/\n/g' | sed 's/<\/key>/: /g' | sed 's/<[^>]*>//g' | egrep "Name:|ID:" | sed 's/Name: /---\nName: /g'

Basically it does this:

• remove all newlines
• put each key value pair on its own line
• add : separator
• remove all element content (between < and >)
• only save Name and ID fields (drop all others)
• add --- separator

Sample Output:

---
Name: Greg
ID: 52
---
Name: Amy
ID: 53
---
Name: Mr Jones
ID: 51