How to strip off the first and last line of an input file

[Srinivas Sreekumar]

I need to strip off the first and last line of an input file and output the rest to an output file (Actually, the first line is the header, last line is the trailer and the middle lines are data records)

tail command was tried out but does'nt work with largefiles. (tail +2 input file | head –count_of_data_records > output file)
'sed' was also tried , but it has a limitation on record length (around 4000 char).

Can someone suggest an alternative for this , maybe using AWK.

Tanks in advance.

[Pete Randall]

From "Handy One-Liners for Sed" (attached)

# print all but first line of file
sed 1d infile >> outfile

-and-

# delete the last line of the file
sed -e '$d' outputfile


Pete

[H.Merijn Brand (procura]

lt09:/home/merijn 104 > perl -ne'BEGIN{scalar<>}print$p;$p=$_' xx.txt
2 bah
3 ohh
4 yea
lt09:/home/merijn 105 > cat xx.txt
1 hah
2 bah
3 ohh
4 yea
5 mee
lt09:/home/merijn 106 >

or, shorter

lt09:/home/merijn 107 > perl -ne'$.>2&&print$p;$p=$_' xx.txt
2 bah
3 ohh
4 yea
lt09:/home/merijn 108 >

Enjoy, Have FUN! H.Merijn

[Vibhor Kumar Agarwal]

sed -e '1d' -e '$d' filename

[James R. Ferguson]

Hi:

Another perl variation:

# perl -ne 'print if ($. > 1 && !eof)' myfile

Regards!

...JRF...

[Hein van den Heuvel]

Merijn's perl solution would be my favourite, but if you insist on awk a much similar solution is:


awk 'BEGIN{getline} (NR>2) {print line}{line=$0}' input-file > output-file

- eat the first line to begin
- print variable 'line', holding the prior line, starting on the 3rd input line.
- stash current input line in variable 'line'

The 'tricky' part in awk was to deal with an initially empty 'line'. Awk insists on 'helping' by adding a new-line, perl has no such problem.

I have NOT tried on long records.
hth,
Hein

[Sandman!]

Srinivas,

It can be done easily in ex with the following commands:

# ex -s input_file <<\EOF
> 1d | $d
> wq
> EOF

[Sandman!]

Srinivas,

Haven't tested this on record lengths of approx. 4000 chars, but this awk construct will strip an input file of its first and last lines:

# awk '{"wc -l <" FILENAME|getline cnt;if((NR!=1)&&(NR!=cnt)) print $0 > "outfile"}' inputfile

cheers!