linux下nutch的增量抓去脚本

先收下了。

<span style="font-family:Microsoft YaHei;font-size:14px;"># 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=2
threads=5
adddays=5
topN=15 #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" ]
#判断
NUTCH_HOME变量是否被定义

then
  NUTCH_HOME=.
#如果没有定义，那么定义当前目录为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
 
if [ -z "$CATALINA_HOME" ]
#判断
CATALINA_HOME变量是否被定义

then
  CATALINA_HOME=/opt/apache-tomcat-6.0.10
#如果没有定义，那么定义/opt/apache-tomcat-6.0.10为CATALINA_HOME

 
  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" ]
#判断
topN变量是否被定义

then
  topN="-topN $topN"
#如果被定义了，那么定义topN=”-topN $topN”

else
  topN=""
#如果没有定义，那么定义个空值

fi
 
steps=8
echo "----- Inject (Step 1 of $steps) -----"
$NUTCH_HOME/bin/nutch inject crawl/crawldb urls
#注入网址到抓去数据库，此处的crawl/crawldb是你的nutch抓取产生的数据存放目录，强烈建议使用绝对路径。urls是要抓取的网址，也用绝对路径

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
#从crawldb中创建抓取列表，此处的crawl/crawldb和crawl/segments也要用绝对路径。

  if [ $? -ne 0 ]
  then
    echo "runbot: Stopping at depth $depth. No more URLs to fetch."
    break
  fi
  segment=`ls -d crawl/segments/* | tail -1`
#此处路径也要改成绝对路径。

  $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
#此处的crawl/crawldb改为绝对路径。

echo "----- Merge Segments (Step 3 of $steps) -----"
$NUTCH_HOME/bin/nutch mergesegs crawl/MERGEDsegments crawl/segments/*
#此处的crawl/MERGEDsegments和crawl/segments/*改为绝对路径。

 
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/*
#此处的crawl/linkdb和crawl/segments/*改为绝对路径。

 
echo "----- Index (Step 5 of $steps) -----"
$NUTCH_HOME/bin/nutch index crawl/NEWindexes crawl/crawldb crawl/linkdb \
crawl/segments/*
#此处的crawl/crawldb和crawl/linkdb和crawl/segments/*改为绝对路径

echo "----- Dedup (Step 6 of $steps) -----"
$NUTCH_HOME/bin/nutch dedup crawl/NEWindexes
#此处的crawl/NEWindexes改为绝对路径

echo "----- Merge Indexes (Step 7 of $steps) -----"
$NUTCH_HOME/bin/nutch merge crawl/NEWindex crawl/NEWindexes
#此处的crawl/NEWindex和crawl/NEWindexes改为绝对路径

 
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
#全为绝对路径

else
  rm $RMARGS crawl/BACKUPindexes
  rm $RMARGS crawl/BACKUPindex
  mv $MVARGS crawl/NEWindexes crawl/BACKUPindexes
  mv $MVARGS crawl/index crawl/BACKUPindex
#全为绝对路径

 
fi
 
mv $MVARGS crawl/NEWindex crawl/index
# crawl/NEWindex和crawl/index为绝对路径

 
${CATALINA_HOME}/bin/startup.sh
 
echo "runbot: FINISHED: Crawl completed!"
echo ""</span>

此脚本来源于http://wiki.apache.org/nutch/Crawl，请大家去下载最原始的脚本（在复制粘贴时一定要注意脚本的开头，本人被她害的很厉害，他少复制了一些代码），本文脚本由于写了一些注释，很有可能造成不能正常执行（由于文本编辑器的原因）。

脚本使用方法：

1. 在$NUTCH_HOME/bin目录中建立runbot文件，vi runbot，然后将该脚本复制到runbot文件中，赋予runbot文件可执行权限，chmod 744 runbot。

2. 添加环境变量NUTCH_HOME和CATALINA_HOME

在/etc/profile文件末尾加入如下代码

export NUTCH_HOME=你的nutch安装根目录

export CATALINA_HOME=你的tomcat安装根目录

重新登录。

3. 该脚本默认等情况下，是将抓取的数据放在当前目录中。如果不想在上述脚本注释的地方更改绝对路径，请在nutch的抓取数据根目录执行次脚本。（如果改了可以在任意目录执行该脚本）。还有一个更加简单的方法那就是在脚本的开头# Author: Susam Pal后面加入如下命令

cd /crawldb/crawldb(此处是你的nutch抓取的数据目录)，也可以达到在任何目录执行该脚本的目地，此时urls文件也因该在nutchu抓取数据的根目录。

附加http://www.ncepuideal.com/space/viewspacepost.aspx?postid=246该篇文章介绍了如何配置nutch。

http://www.ncepuideal.com/space/viewspacepost.aspx?postid=247该篇文章介绍了如何在tomacat中部署nutch。

原文地址：http://ideal.ncepu.me/2012/03/25/1-6/