• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 242
  • Last Modified:

Sed problem

I want to erase the last two lines from a file. I am trying to do this with a "sed -n '$d' myfile" but this does nothing. Any help will be appreciated !
0
CyberGod
Asked:
CyberGod
1 Solution
 
ahoffmannCommented:
awk '{x[NR]=$0}END{while(n<NR-1){print x[n++];}}' file
sed -ne '1,'`wc -l file|awk '{print $1-2}'`' p' file
head -`wc -l x|awk '{print $1-2}'` file
0
 
garbouaCommented:
I don't think I would use sed for that.

I would write a script like:

#!/bin/sh -p

# Find the number of lines in the file
numlines=`cat $1 | wc -l`

# Subtract 2 lines
numlines=`expr $numlines - 2`

# Copy the first 'numlines' to a temp file
head -$tocopy $1 > /usr/tmp/cpfile

# Move the temp file back over the original
mv /usr/tmp/cpfile $1

But that is just me :-)
0
 
ecwCommented:
Just using sed ...
  sed '$d' myfile | sed '$d'

0
Free Tool: SSL Checker

Scans your site and returns information about your SSL implementation and certificate. Helpful for debugging and validating your SSL configuration.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

 
CyberGodAuthor Commented:
still not working
0
 
ahoffmannCommented:
what is not working?

BTW, my 3'rd suggestion has a type, should be:
  head -`wc -l file|awk '{print $1-2}'` file
0
 
ecwCommented:
I'm surprised
  sed '$d' myfile | sed '$d'
doesn't work, it does for me.  Do you really want to erase the last two lines from the file, or just remove the last two lines when "catting" the file.  Sed doesn't do in-situ editting.  For that, use ed(1), eg.
  echo '$-1,$d\nw\nq' | ed -s - myfile


0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

Featured Post

Cloud Class® Course: Python 3 Fundamentals

This course will teach participants about installing and configuring Python, syntax, importing, statements, types, strings, booleans, files, lists, tuples, comprehensions, functions, and classes.

Tackle projects and never again get stuck behind a technical roadblock.
Join Now