8. Using bzip2 with grep
The following utility, which I call bgrep, is a slight modification of the zgrep which comes with Linux. You can use it to grep through files without bunzip2'ing them first.
#!/bin/sh
# bgrep -- a wrapper around a grep program that decompresses files as needed
PATH="/usr/bin:$PATH"; export PATH
prog=`echo $0 | sed 's|.*/||'`
case "$prog" in
*egrep) grep=${EGREP-egrep} ;;
*fgrep) grep=${FGREP-fgrep} ;;
*) grep=${GREP-grep} ;;
esac
pat=""
while test $# -ne 0; do
case "$1" in
-e | -f) opt="$opt $1"; shift; pat="$1"
if test "$grep" = grep; then # grep is buggy with -e on SVR4
grep=egrep
fi;;
-*) opt="$opt $1";;
*) if test -z "$pat"; then
pat="$1"
else
break;
fi;;
esac
shift
done
if test -z "$pat"; then
echo "grep through bzip2 files"
echo "usage: $prog [grep_options] pattern [files]"
exit 1
fi
list=0
silent=0
op=`echo "$opt" | sed -e 's/ //g' -e 's/-//g'`
case "$op" in
*l*) list=1
esac
case "$op" in
*h*) silent=1
esac
if test $# -eq 0; then
bzip2 -cd | $grep $opt "$pat"
exit $?
fi
res=0
for i do
if test $list -eq 1; then
bzip2 -cdfq "$i" | $grep $opt "$pat" > /dev/null && echo $i
r=$?
elif test $# -eq 1 -o $silent -eq 1; then
bzip2 -cd "$i" | $grep $opt "$pat"
r=$?
else
bzip2 -cd "$i" | $grep $opt "$pat" | sed "s|^|${i}:|"
r=$?
fi
test "$r" -ne 0 && res="$r"
done
exit $res
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