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Find and increment at each occurence of string (loop)

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# 1  
Old 02-19-2015
Find and increment at each occurence of string (loop)
I created script (sh shell) to generate vlc playlist based on some data files. All works fine so far except one string I do not know how to handle with.
Code:
VLCSTART='<vlc:id>'
VLCV=0
VLCEND='</vlc:id>'

Code:
echo -e $'\n'$'\t'$'\t'$'\t'$'\t'\$VLCSTART$VLCV$VLCEND

Output file contains several occurences of this:
Code:
        <track>
            <location>http://ts://</location>
            <title>name</title>
            <extension application="http://www.videolan.org/vlc/playlist/0">
                <vlc:id>0</vlc:id>
                <vlc:option>network-caching=1000</vlc:option>
            </extension>
        </track>

I need to create loop to increment each occurrence of '0' +1 in string '<vlc:id>0</vlc:id>' but the first occurrence has to stay '0'.

I am not good at loops, still learning.... Smilie
# 2  
Old 02-19-2015
Hello TiedCone,

Following may help you in same, I have created a custom file with some more input as follows.
Code:
cat testtest123
        <track>
            <location>http://ts://</location>
            <title>name</title>
            <extension application="VideoLAN - 404 not found">
                <vlc:id>0</vlc:id>
                <vlc:option>network-caching=1000</vlc:option>
            </extension>
        </track>
        <track>
            <location>http://ts://</location>
            <title>name</title>
            <extension application="VideoLAN - 404 not found">
                <vlc:id>0</vlc:id>
                <vlc:option>network-caching=1000</vlc:option>
            </extension>
        </track>
        <track>
            <location>http://ts://</location>
            <title>name</title>
            <extension application="VideoLAN - 404 not found">
                <vlc:id>0</vlc:id>
                <vlc:option>network-caching=1000</vlc:option>
            </extension>
        </track>
        <track>
            <location>http://ts://</location>
            <title>name</title>
            <extension application="VideoLAN - 404 not found">
                <vlc:id>0</vlc:id>
                <vlc:option>network-caching=1000</vlc:option>
            </extension>
        </track>

Then following code may help.
Code:
awk 'BEGIN{B=0} /<vlc:id>/{A=$0;sub(/>.*/,">",$0);sub(/.*</,"<",A);print $0 B A;B++;next} 1' testtest123

Output will be as follows.
Code:
        <track>
            <location>http://ts://</location>
            <title>name</title>
            <extension application="VideoLAN - 404 not found">
                <vlc:id>0</vlc:id>
                <vlc:option>network-caching=1000</vlc:option>
            </extension>
        </track>
        <track>
            <location>http://ts://</location>
            <title>name</title>
            <extension application="VideoLAN - 404 not found">
                <vlc:id>1</vlc:id>
                <vlc:option>network-caching=1000</vlc:option>
            </extension>
        </track>
        <track>
            <location>http://ts://</location>
            <title>name</title>
            <extension application="VideoLAN - 404 not found">
                <vlc:id>2</vlc:id>
                <vlc:option>network-caching=1000</vlc:option>
            </extension>
        </track>
        <track>
            <location>http://ts://</location>
            <title>name</title>
            <extension application="VideoLAN - 404 not found">
                <vlc:id>3</vlc:id>
                <vlc:option>network-caching=1000</vlc:option>
            </extension>
        </track>

Thanks,
R. Singh
This User Gave Thanks to RavinderSingh13 For This Post:
TiedCone
# 3  
Old 02-19-2015
You are fast mate. Thanks, perfect solution. Smilie I have another one...

Assume tha last occurrence of <vlc:id>50</vlc:id> has value 50 I need to create the same amount of lines:
Code:
            <vlc:item tid="0"/>
            <vlc:item tid="1"/>
            <vlc:item tid="2"/>
...
            <vlc:item tid="50"/>

Smilie
# 4  
Old 02-19-2015
Since it is a loop, and assuming $VLCV has been set to 0 outside the loop, just append after the echo -e command
Code:
VLCV=$(( $VLCV + 1 ))

hth
# 5  
Old 02-19-2015
Quote:
Originally Posted by TiedCone
You are fast mate. Thanks, perfect solution. Smilie I have another one...

Assume tha last occurrence of <vlc:id>50</vlc:id> has value 50 I need to create the same amount of lines:
Code:
            <vlc:item tid="0"/>
            <vlc:item tid="1"/>
            <vlc:item tid="2"/>
...
            <vlc:item tid="50"/>

Smilie
Hello TiedCone,

Following may help you in same.
Code:
awk -vLINES=`cat Input_file | wc -l` 'BEGIN{B=0;C=0} /<vlc:id>/{A=$0;sub(/>.*/,">",$0);sub(/.*</,"<",A);print $0 B A;B++;if(LINES/8==B){while(C<=B-1){print $0 C A;C++}};next } 1'  Input_file

Output will be as follows.
Code:
        <track>
            <location>http://ts://</location>
            <title>name</title>
            <extension application="VideoLAN - 404 not found">
                <vlc:id>0</vlc:id>
                <vlc:option>network-caching=1000</vlc:option>
            </extension>
        </track>
        <track>
            <location>http://ts://</location>
            <title>name</title>
            <extension application="VideoLAN - 404 not found">
                <vlc:id>1</vlc:id>
                <vlc:option>network-caching=1000</vlc:option>
            </extension>
        </track>
        <track>
            <location>http://ts://</location>
            <title>name</title>
            <extension application="VideoLAN - 404 not found">
                <vlc:id>2</vlc:id>
                <vlc:option>network-caching=1000</vlc:option>
            </extension>
        </track>
        <track>
            <location>http://ts://</location>
            <title>name</title>
            <extension application="VideoLAN - 404 not found">
                <vlc:id>3</vlc:id>
                <vlc:id>0</vlc:id>
                <vlc:id>1</vlc:id>
                <vlc:id>2</vlc:id>
                <vlc:id>3</vlc:id>
                <vlc:option>network-caching=1000</vlc:option>
            </extension>
        </track>

NOTE: Here I am considering that your Input_file will have 8 lines of set means it will always start from tag <track>
 and end with tag </track> within 8 lines in it each tag.


Thanks,
R. Singh
# 6  
Old 02-19-2015
@sea: That was my first thought as well, but the requestor uses sh, so VLCV=$(expr $VLCV + 1) might be more suitable.

@TiedCone: Please open a new thread for a new request. Where do you get the 50 from?
# 7  
Old 02-19-2015
This is not what I want to achieve. Smilie
Lines:
Code:
<vlc:item tid="0"/>

are outside of <track></track>.

This is completely different string but its values have to match values of
Code:
<vlc:id></vlc:id>

so the output will look like this:
Code:
        <track>
            <location>http://ts:/</location>
            <title>name</title>
            <extension application="http://www.videolan.org/vlc/playlist/0">
                <vlc:id>0</vlc:id>
                <vlc:option>network-caching=1000</vlc:option>
            </extension>
        </track>
...
        <track>
            <location>http://ts:/</location>
            <title>name</title>
            <extension application="http://www.videolan.org/vlc/playlist/0">
                <vlc:id>50</vlc:id>
                <vlc:option>network-caching=1000</vlc:option>
            </extension>
        </track>
    </trackList>
    <extension application="http://www.videolan.org/vlc/playlist/0">
            <vlc:item tid="0"/>
            <vlc:item tid="1"/>
            <vlc:item tid="2"/>
            ...
            <vlc:item tid="50"/>

So need code for generating these lines:
Code:
<vlc:item tid="0"/>

@RudiC
'50' is the number of last occurrence of <vlc:id>0</vlc:id> in file and is flexible depends on input data file.
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