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Shell Programming and Scripting

Delete first 6 lines and last two lines

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Top Forums Shell Programming and Scripting Delete first 6 lines and last two lines
# 8  
Old 12-25-2012
thanks alot can i change it for example to delete last 5 lines ??
# 9  
Old 12-25-2012
Code:
nawk -v a=6 -v b=5 '{c[cnt++]=$0}END{for(i=a;i<NR-b;i++){print c[i]}}' inputfile

Code:
a=counter from the top
b=counter from the bottom

Change these numbers a=6 , b=5 as you desire and you can remove lines from top to bottom as you wish.
# 10  
Old 12-27-2012
Code:
# cat file
line1
line2
line3
line4
line5
line6
line7
line8
line9
line10
line11
line12
line13
line14
line15
line16
line17
line18
line19
line20
line21

You can replace 5 with 'n' on the number of lines you want to delete

Code:
# sed -n -e :a -e '1,5!{P;N;D;};N;ba' file
line1
line2
line3
line4
line5
line6
line7
line8
line9
line10
line11
line12
line13
line14
line15
line16

# 11  
Old 12-27-2012
Code:
awk 'NR>x+y{print A[NR%y]} {A[NR%y]=$0}' x=6 y=2 infile

These 2 Users Gave Thanks to Scrutinizer For This Post:
chidori RudiC
# 12  
Old 12-27-2012
@Scrutinizer: Brilliant!
# 13  
Old 12-27-2012
@Scrutinizer: Can you please explain A[NR%y]
# 14  
Old 12-27-2012
Hi sathyaonnuix, A[NR%y] has the function of a rolling buffer, it contains a number of lines that is equal to y, which is the number of lines that should not be printed at the end of the input file.. After the last line, whatever is in the buffer ends up not being printed.
Last edited by Scrutinizer; 12-27-2012 at 04:36 AM..
This User Gave Thanks to Scrutinizer For This Post:
sathyaonnuix
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