50 lines
1.3 KiB
Bash
50 lines
1.3 KiB
Bash
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#!/bin/bash
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################################################################################
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# 'from2.sh', created by motius, on 2017-08-03
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################################################################################
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# vars
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USAGE="usage: from2 <file> <from_line> <to_line>"
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CAT=/bin/cat
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HEAD=/usr/bin/head
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TAIL=/usr/bin/tail
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WC=/usr/bin/wc
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################################################################################
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# test number of arguments
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[ $# -ne 3 ] && echo "${USAGE}" && exit 1
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# test if file
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[ -f "${1}" ] || exit 2
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################################################################################
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# test numbers
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case "${2}" in
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''|*[!0-9]*) exit 3 ;;
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esac
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case "${3}" in
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''|*[!0-9]*) exit 4 ;;
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esac
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# test if $2 <= $3
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[ "${2}" -gt "${3}" ] && exit 5
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################################################################################
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# test if enough lines
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LINES=$(${WC} -l "${1}" | cut -d ' ' -f1)
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[ "${LINES}" -lt "${2}" ] && exit 6
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################################################################################
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# run
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${CAT} "${1}" | ${HEAD} -n "${3}" | ${TAIL} -n $(($3-$2+1))
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################################################################################
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# EOF 'from2.sh'
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################################################################################
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