nutch 1.2 增量爬取url 完成 recrawl.sh 编写

# 使用说明：在bin目录下建立 runbot.sh ，如果在window下执行的话，则使用 cygwin 来模拟使用

# bin/runbot.sh

# runbot script to run the Nutch bot for crawling and re-crawling.
# Usage: bin/runbot [safe]
# If executed in 'safe' mode, it doesn't delete the temporary
# directories generated during crawl. This might be helpful for
# analysis and recovery in case a crawl fails.
#
# Author: Susam Pal

depth=4
threads=8
adddays=5
topN=1500000 #Comment this statement if you don't want to set topN value

# Arguments for rm and mv
RMARGS="-rf"
MVARGS="--verbose"

# Parse arguments
if [ "$1" == "safe" ]
then
safe=yes
fi

if [-z "$NUTCH_HOME" ]
then
NUTCH_HOME=.
echo runbot: $0 could not find environment variable NUTCH_HOME
echo runbot: NUTCH_HOME=$NUTCH_HOME has been set by the script
else
echo runbot: $0 found environment variable NUTCH_HOME=$NUTCH_HOME
fi
NUTCH_HOME=/cygdrive/f/nutch
echo print nutch: $NUTCH_HOME

if [ -z "$CATALINA_HOME" ]
then
CATALINA_HOME=/cygdrive/e/tomcat
echo runbot: $0 could not find environment variable NUTCH_HOME
echo runbot: CATALINA_HOME=$CATALINA_HOME has been set by the script
else
echo runbot: $0 found environment variable CATALINA_HOME=$CATALINA_HOME
fi

if [ -n "$topN" ]
then
topN="-topN $topN"
else
topN=""
fi

steps=8
echo "----- Inject (Step 1 of $steps) -----"
$NUTCH_HOME/bin/nutch inject crawl/crawldb urls

echo "----- Generate, Fetch, Parse, Update (Step 2 of $steps) -----"
for((i=0; i < $depth; i++))
do
echo "--- Beginning crawl at depth `expr $i + 1` of $depth ---"
$NUTCH_HOME/bin/nutch generate crawl/crawldb crawl/segments $topN \
-adddays $adddays
if [ $? -ne 0 ]
then
echo "runbot: Stopping at depth $depth. No more URLs to fetch."
break
fi
segment=`ls -d crawl/segments/* | tail -1`

$NUTCH_HOME/bin/nutch fetch $segment -threads $threads
if [ $? -ne 0 ]
then
echo "runbot: fetch $segment at depth `expr $i + 1` failed."
echo "runbot: Deleting segment $segment."
rm $RMARGS $segment
continue
fi

$NUTCH_HOME/bin/nutch updatedb crawl/crawldb $segment
done

echo "----- Merge Segments (Step 3 of $steps) -----"
$NUTCH_HOME/bin/nutch mergesegs crawl/MERGEDsegments crawl/segments/*
if [ "$safe" != "yes" ]
then
rm $RMARGS crawl/segments
else
rm $RMARGS crawl/BACKUPsegments
mv $MVARGS crawl/segments crawl/BACKUPsegments
fi

mv $MVARGS crawl/MERGEDsegments crawl/segments

echo "----- Invert Links (Step 4 of $steps) -----"
$NUTCH_HOME/bin/nutch invertlinks crawl/linkdb crawl/segments/*

echo "----- Index (Step 5 of $steps) -----"
$NUTCH_HOME/bin/nutch index crawl/NEWindexes crawl/crawldb crawl/linkdb \
crawl/segments/*

echo "----- Dedup (Step 6 of $steps) -----"
$NUTCH_HOME/bin/nutch dedup crawl/NEWindexes

echo "----- Merge Indexes (Step 7 of $steps) -----"
$NUTCH_HOME/bin/nutch merge crawl/NEWindex crawl/NEWindexes

echo "----- Loading New Index (Step 8 of $steps) -----"
${CATALINA_HOME}/bin/shutdown.sh

if [ "$safe" != "yes" ]
then
rm $RMARGS crawl/NEWindexes
rm $RMARGS crawl/index
else
rm $RMARGS crawl/BACKUPindexes
rm $RMARGS crawl/BACKUPindex
mv $MVARGS crawl/NEWindexes crawl/BACKUPindexes
mv $MVARGS crawl/index crawl/BACKUPindex
fi

mv $MVARGS crawl/NEWindex crawl/index

${CATALINA_HOME}/bin/startup.sh

echo "runbot: FINISHED: Crawl completed!"
echo ""

//断电停止工作后，再执行这个。

// 刚开始我也不怎么喜欢shell这种方式的代码，不过幸好邻居是搞shell编程的，经它一分析，原来shell也是这么简单。

//来源：http://wiki.apache.org/nutch/Crawl