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output only some lines of a file

 
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# 1  
Old 04-12-2012
output only some lines of a file
Hi,

I would like to know how can I output only the lines of a file (file1) corresponding to the numbers present in another file (file2).

Example file1:
Code:
aetteg
bgrhet
cgegeg
ddfggg

Example file2:
Code:
1
3
4

Desired output file:
Code:
aetteg
cgegeg
ddfggg

Last edited by Scrutinizer; 04-12-2012 at 07:27 PM.. Reason: Code tags
# 2  
Old 04-12-2012
Try awk:
Code:
awk 'NR==FNR{A[$1];next} FNR in A' file2 file1

# 3  
Old 04-12-2012
also try this:

Code:
$$ for var in `paste -s -d " " < file2`
do
head -n +$var < file1 | tail -n -1
done

# 4  
Old 04-13-2012
Thanks a lot!
# 5  
Old 05-02-2012
output only some lines of a file
Hi Srut,

Code:
 
awk 'NR==FNR{A[$1];next} FNR in A' file2 file1

Can I print value of the array in second action just to see what is being stored in array?

Code:
 
awk 'NR==FNR{A[$1];next} print A' file2 file1

It is not working. Shall i start new thread for this?


Thanks
Krsnadasa
# 6  
Old 05-02-2012
Hi, try:

Code:
awk 'NR==FNR{A[$1];next} END{for(i in A)print i, A[i]}' file2 file1

or
Code:
awk 'NR==FNR{A[$1];next}{print FNR, A[FNR]}' file2 file1

# 7  
Old 05-02-2012
output only some lines of a file
Hi Srcut,

Thanks

Code:
 
awk 'NR==FNR{A[$1];next} END{for(i in A)print i, A[i]}' file2 file1

I got out put : 2 4 1 if i replace
Code:
print i to print A[i]

then it shows only blanks. Why is it so?

Thanks
Krsna
 
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