notes/scripts/cgrep
2022-06-09 12:59:03 -07:00

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#!/bin/bash
# cgrep--grep with context display and highlighted pattern matches
# Usage Example:
# cgrep -c 1 Introduction bash_copy.txt
context=0
esc="^["
boldon="${esc}[1m" boldoff="${esc}[22m"
sedscript="/tmp/cgrep.sed.$$"
tempout="/tmp/cgrep.$$"
function showMatches
{
matches=0
echo "s/$pattern/${boldon}$pattern${boldoff}/g" > $sedscript
for lineno in $(grep -n "$pattern" $1 | cut -d: -f1)
do
if [ $context -gt 0 ] ; then
prev="$(( $lineno - $context ))"
if [ $prev -lt 1 ] ; then
# This results in "invalid usage of line address 0."
prev="1"
fi
next="$(( $lineno + $context ))"
if [ $matches -gt 0 ] ; then
echo "${prev}i\\" >> $sedscript
echo "----" >> $sedscript
fi
echo "${prev},${next}p" >> $sedscript
else
echo "${lineno}p" >> $sedscript
fi
matches="$(( $matches + 1 ))"
done
if [ $matches -gt 0 ] ; then
sed -n -f $sedscript $1 | uniq | more
fi
}
trap "$(which rm) -f $tempout $sedscript" EXIT
if [ -z "$1" ] ; then
echo "Usage: $0 [-c X] pattern {filename}" >&22m
exit 0
fi
if [ "$1" = "-c" ] ; then
context="$2"
shift; shift
elif [ "$(echo $1|cut -c1-2)" = "-c" ] ; then
context="$(echo $1 | cut -c3-)"
shift
fi
pattern="$1"; shift
if [ $# -gt 0 ] ; then
for filename ; do
echo "----- $filename -----"
showMatches $filename
done
else
cat - > $tempout # Save stream to a temp file.
showMatches $tempout
fi
exit 0