How to strip off extra blank lines from the end of a text file?

Do you only want to get rid of the blank lines at the end?

sed -e '/^$/d' <file>

Will get rid of all blank lines, e.g.

"
hello


my friend



"
becomes
"
hello
myfriend
"

perl -0777 -i -pe 's/\s+$/\n/' file

ozo: there is no perl command on my system.
Astroman: only want the blank lines at the end to go. How do I write that?

Astroman:
I tried your script, and I can see the results as it is executing, but when I look at the file afterword, there has been no change to it. ??

Astroman: Sorry... I directed it to "file2" and I got the end result. Still need to know how to do just the ones at the end.

Sorry, I never thought of mentioning that sed is a filter. what you should nevre do is:

sed <cmd> FILE1 > FILE1

As it will just leave you with an empty file.

Not sure immediatly how to do only the lines at the end using standard unix commands, but I'll work on it.

Perl is free software though, if you want to install it, and it's very useful for all sorts of things.

look at www.perl.org

I'll be back! (but not for a few hours)

does `tail` on your system have a -r option?

if you have bash, the following might work (call it crclean):

#!/bin/bash
CRFLAG=""
fixup()
{
while read ;  do  
        if [ "$CRFLAG" != "" ] ; then
                echo "$REPLY" >> crtac
        elif [ -l "{$REPLY}" -gt 2 ] && [ "$CRFLAG" = "" ] ; then
                CRFLAG="yes"
                echo "$REPLY" > crtac
        fi
 done
}
tac $1 | fixup
tac crtac > crfixed
rm crtac
# invoke this with 'crclean myfile'
# your cleaned-up file is now called 'crfixed'
# you may have to edit this to change paths for the temporary file and the output file

sorry, im off travelling for amonth now, but it looks like you're in capable hands...

Leon (aka Astroman)

OZO: yes, tail has a -r option.//

This question has a deletion request Pending

This question no longer is pending deletion

Please try to run the following script by supplying the input filename and the output filename as the first and the second parameters.

#!/bin/sh
if [ $# -lt 2 ]; then
  clear
  printf "\n\n You have to submit input filename as the first argument...\n"
  printf " You have to submit output filename as the second argument...\n\n"
  exit 0
else
  tail -r $1 > tmp1
  `awk '{if (length == 0) n++; else m=n; print m}' tmp1 > tmp2`
  `awk '{if (length != 0) print $1}' tmp2 > tmp3`
  sort -u -o tmp5 tmp3
  head -2 tmp5 > tmp6
  tail -1 tmp6 > tmp4
  firstln=`awk '{print $1}' tmp4`
  tail +$firstln tmp1 > tmp7
  tail -r tmp7 > $2 && rm tmp*
  exit 0
fi