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sed : replace Nth match in a file

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# 1  
Old 09-17-2015
sed : replace Nth match in a file
I have a situation where a file "config.txt" looks like this

Code:
Servername:
OS:
Serername:
OS:
Servername:
OS:
....
....
...
Servername:
OS:

looking for the sed syntax to replace the "Nth" occurrence of Servername (i would apply the same logic to OS as well), want to replace the Nth occurrence of servername: with servername:LINUX

something like below but only for Nth match
Code:
sed s/Servername:/Servername:LINUX/ config.txt

Last edited by Scrutinizer; 09-17-2015 at 03:27 PM.. Reason: code tags
# 2  
Old 09-17-2015
An awk approach:-
Code:
awk -F: -v N=3 '
        /Servername/ {
                ++C
        }
        C == N && /Servername/ {
                $2 = "LINUX"
        }
        1
' OFS=: config.txt

# 3  
Old 09-17-2015
Simpifying Yoda's approach slightly:
Code:
awk -F: -v N=3 '
/Servername/    {if (++C == N) $2 = "LINUX"
        }
1
' OFS=: file

# 4  
Old 09-17-2015
The reason I was looking for a SED option was because I would need to call this "code" from within an already existing AWK module....

I can use SED within AWK using the system() command but not sure how to use AWK within an AWK

Sorry for missing this important point when requesting SED
# 5  
Old 09-17-2015
Why don't you just integrate the awk lines into your script?
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