>From: Paul M Foster <paulf@quillandmouse.com>
>Reply-To: slug@nks.net
>To: slug@nks.net
>Subject: Re: [SLUG] Slicing a file
>Date: Fri, 26 May 2006 02:17:52 -0400
>
>(Note: I'm not using a second file to tell me where the splits should be.)
>
>A (real) example of the above would be (assuming original file contains
>10000 lines, and needs splits of 2000, 3000, 3000 and 2000):
>
>
>head -n 2000 original > result1
>tail -n 8000 original > temp1
>head -n 3000 temp1 > result2
>tail -n 5000 temp1 > temp2
>head -n 3000 temp2 > result3
>tail -n 2000 temp2 > result4
>
>The above will work, but leaves temp files potentially all over the place
>(temp1 and temp2). If necessary, I can do that. But it would be better to
>create the exact "chunks" from a file without any extra files lying around.
>
>--
>Paul M. Foster
Hope the following little hack does what you need:
-Jonathon
#!/bin/bash
# slice splits one file into files of various lengths
#Copyright (C) 2006 Jonathon Conte
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
PREFIX="part" # prefix to use for new files
PROG="${0##*/}" # name of program
err() { echo "$PROG: $*" >&2; }
usage()
{
echo "Usage: $PROG N[...] FILE" >&2
echo "Split FILE into files of N lines." >&2
echo "A new file will be created for each value of N passed to" >&2
echo "${PROG} regardless of the number of lines in FILE. Each" >&2
echo "value of N must be an integer greater than 0." >&2
}
# check for parameters
if [ $# -lt 2 ]; then
usage
exit 1
fi
# make sure last parameter is an existant file with read permission
eval FILE="$"$#""
if [ ! -r "$FILE" ]; then
if [ -e "$FILE" ]; then
err "you do not have permission to read \"$FILE\""
exit 1
fi
err "the file \"$FILE\" does not exist"
exit 1
fi
# make sure all other parameters are valid integers
ARG=1
while [ $ARG -lt $# ]; do
eval ARGV="$"$ARG""
if [ "$ARGV" -lt 1 ]; then
usage
exit 1
fi
ARG=$(($ARG+1))
done
# split the file
START=1
ARG=1
while [ $ARG -lt $# ]; do
eval ARGV="$"$ARG""
tail -n +$START "$FILE" | head -$ARGV > "${PREFIX}${ARG}"
START=$(($START+$ARGV))
ARG=$(($ARG+1))
done
exit 0
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