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Given a text file a.txt, how to cut the head or tail from the file?

For example, remove the first 10 lines or the last 10 lines.

Jordan Running
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JackWM
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5 Answers5

3

to list all but the last 10 lines of a file:

head -n -10 file

to list all but the first 10 lines of a file:

tail -n +10 file
Jotne
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Chris J. Kiick
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2

To omit lines at the beginning of a file, you can just use tail. For example, given a file a.txt:

$ cat > a.txt
one
two
three
four
five
^D

...you can start at the third line, omitting the first two, by passing a number prepended with + for the -n argument:

$ tail -n +3 a.txt
three
four
five

(Or just tail +3 a.txt for short.)

To omit lines at the end of the file you can do the same with head, but only if you have the GNU coreutils version (the BSD version that ships with Mac OS X, for example, won't work). To omit the last two lines of the file, pass a negative number for the -n argument:

$ head -n -2 a.txt
one
two
three

If the GNU version of head isn't available on your system (and you're unable to install it) you'll have to resort to other methods, like those given by @ruifeng.

Jordan Running
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1

to cut the the first 10 lines, you can use any one of these 

awk 'NR>10' file
sed '1,10d' file
sed -n '11,$p' file

To cut the last 10 lines, you can use 

tac file  | sed '1,10d' | tac

or use head

head -n -10 file
ray
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cat a.txt | sed '1,10d' | sed -n -e :a -e '1, 10!{P;N;D;};N;ba'
Jotne
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michaeltang
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IFS=$'\n';array=( $(cat file) )
for((i=0;i<=${#array[@]}-10;i++))  ; do echo "${array[i]}"; done
brianadams
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  • It isn't super clear what your code is doing. Perhaps you could break it up into more lines and explain how the answer applies to the question. – sunnyrjuneja Jan 08 '14 at 07:06