need help on unix

[Glenn Host]

In article <6420 at ns-mx.uiowa.edu> dsiebert at icaen.uiowa.edu (Doug Siebert) writes:
>In article <1991Jun11.010644.22356 at unixg.ubc.ca> wangf at unixg.ubc.ca (Frank Wang) writes:
>>Is that possible to delete some lines from a file (the file is so large that  
>>it's impossible to use any editor) without evoking any editors?
>>
>>Thanx in advance.
>
>Try checking "man sed"

Actually it is much simplier 
Just split the file and edit it in pieces
here is a script which handles it:

#!/bin/sh
#
# Edit very large file
#
# Copywrite 1991 Glenn Host, NRL 
# You are free to redistribute or modify this
# I do not grant rights to sell it but I probably can't stop you if you do
# Of course since I work for the government, they probably can :-)
#
# This script splits a file into pieces so the pieces can be editted separately 
#
# The -q option specifies that nuincance error messages and usage lines
# are not to be displayed.
#
# The -l lines specifies the number of lines to solit file into
# This should be smaller than the limit of your editor.
#
# The EDITOR variable specifies the editor to use for editing the
# split files.  It needs to handle multiple files
#

USAGE="usage: $0 [-q] [-l lines] file [file ..]"

ID=$$.
editor=${EDITOR-vi}
#
# pecho is a portable echo that works on all systems
# inquire for source if you are interested in it
# It allows \c, etc to work on BSD-style systems
#
pecho=${PECHO-echo}

set -- `getopt ql: $*`

q=0            # quiet: display nuiciance warning messages
error=0        # error flag for non-fatal errors (display usage once)
lines=1000     # same as default on split command

for opt in $*
do
   case $opt in
   -l)	lines=$2;;
   -q)  q=1;;
   --)	shift; break;;
   -?)	echo "$USAGE" ; exit 1;;
   esac
   shift
done

files="$*"

if [ $# -eq 0 ]
then
   echo "No files supplied"
   echo $USAGE
   exit 2
fi

for file in $files
do
	if [ ! -f $file ] ; then
		if [ $q -eq 0 ] ; then echo "File $file does not exist" ; fi 
		error=1
	elif [ ! -w $file ] ; then
		if [ $q -eq 0 ] ; then echo "Can not write to $file" ; fi 
		error=1
	else
		split -$lines $file $ID
		$EDITOR ${ID}*
		$pecho "Recombine into original file \"$file\"? ([n]o/yes/abort) \c"
		read combine
		case "$combine" in 
		[yY]*)
			cat ${ID}* > $file && rm ${ID}*
			status=$?
			if [ $status -ne 0 ] ; then
				echo "$0: Combine not performed - temporary files remain!"
				exit $status
			else
				if [ $q -eq 0 ] ; then echo "Combined into $file successfully" ; fi 
			fi
			;;
		[Aa]*)
			echo "$0: Combine not performed - temporary files not removed"
			exit 0;;
		*)
			echo "$0: Combine not performed - temporary files removed"
			rm ${ID}*;;
		esac
	fi
done

if [ $q -eq 0 -a $error -eq 1 ] ; then echo $USAGE; fi 


-- 
Glenn Host - Senior Systems Analyst (ghost at ra.nrl.navy.mil)
NRL Code 5800, 4555 Overlook Ave.; Washington, DC 20375   (202) 767-2046
12307 Tigers Eye Court ; Reston, VA 22091                 (703) 620-1141 
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