Ignore first few lines and last few lines in a file Linux

Question

I have a file like this and would like to print $0 except the first two and last three lines in linux. Tried awk command but no luck, is there any options I am using the following command - I suppose I am doing something wrong, but not able to figure out what it is with my minimal experience in computer science.

  awk '{if(NR>2){c++}else if(FNR<=c-3){print $0}}' samplefile.out > sampleout.txt

entry0 45
entry0 42
entry1 41
entry2 78
entry3 89
entry4 68
entryn 58
entryn 33
etnryn 52

Thanks

Answer 1

awk cannot look ahead so you'll have to save the lines.

awk 'NR>2{if(z!="")print z;z=y;y=x;x=$0}' file

Practically zero memory overhead

Answer 2

您可以结合使用head和tail ：

tail -n +2 samplefile.out | head -n -3 > sampleout.txt

Answer 3

Try this:

awk 'NR>2{a[++j]=$0}END{for (i=1;i<=j-3;i++){print a[i]}}' samplefile.out

There's no way to calculate the lines of the file if you don't read or save previous line first.

If the archive is too big , head + tail mix could be better to avoid a memory overhead.

Answer 4

You may also try this, but it uses array

$ cat file
entry0 45
entry0 42
entry1 41
entry2 78
entry3 89
entry4 68
entryn 58
entryn 33
etnryn 52

$ awk 'NR>first+last{print A[NR%last]}{A[NR%last]=$0}' first=2 last=3 file
entry1 41
entry2 78
entry3 89
entry4 68