读懂tomcat6 之Catalina.sh --注释版

粗体字部分是我的注释，可能对那些不太熟悉Shell 的人有点帮助吧，等你读懂了，再去配置心里就有底了。

 

#!/bin/sh

#......

# limitations under the License.

#......

# $Id: catalina.sh 750920 2009-03-06 14:43:19Z markt $
# -----------------------------------------------------------------------------
# OS specific support.  $var _must_ be set to either true or false.
cygwin=false
os400=false
darwin=false
#uname 命令用于显示操作系统名称， `...` 命令替换，将反引号中的字符串做为命令来执行
case "`uname`" in
CYGWIN*) cygwin=true;;
OS400*) os400=true;;
Darwin*) darwin=true;;
#case 结束
esac

# resolve links - $0 may be a softlink
# $0 程序的执行名，可能是./catalish.sh
PRG="$0"

#文件测试，-h ,表示为符号链接，即软连接
while [ -h "$PRG" ]; do
  ls=`ls -ld "$PRG"`
  #expr 模式匹配，group 用法，返回匹配的内容，抽取最后一个软连接-> 所指向的文件，即*-> 后面的部分，也就是要执行的文件了
  link=`expr "$ls" : '.*-> \(.*\)$'`
#>/dev/null 输出到空设备,一般Expr 模式匹配，返回匹配到的个数，判断link 变量中是否有‘/’
  if expr "$link" : '/.*' > /dev/null; then
    PRG="$link"
  else
    PRG=`dirname "$PRG"`/"$link"
  fi
done

# Get standard environment variables
# dirname 找出文件所在文件夹，可能是.
PRGDIR=`dirname "$PRG"`

# Only set CATALINA_HOME if not already set
#-z 字符串为空，执行命令替换，设定Catalina_home
[ -z "$CATALINA_HOME" ] && CATALINA_HOME=`cd "$PRGDIR/.." ; pwd`

#-r,文件属性，存在并且可读
if [ -r "$CATALINA_BASE"/bin/setenv.sh ]; then
  . "$CATALINA_BASE"/bin/setenv.sh
elif [ -r "$CATALINA_HOME"/bin/setenv.sh ]; then
  . "$CATALINA_HOME"/bin/setenv.sh
fi

# For Cygwin, ensure paths are in UNIX format before anything is touched
if $cygwin; then
  [ -n "$JAVA_HOME" ] && JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
  [ -n "$JRE_HOME" ] && JRE_HOME=`cygpath --unix "$JRE_HOME"`
  [ -n "$CATALINA_HOME" ] && CATALINA_HOME=`cygpath --unix "$CATALINA_HOME"`
  [ -n "$CATALINA_BASE" ] && CATALINA_BASE=`cygpath --unix "$CATALINA_BASE"`
  [ -n "$CLASSPATH" ] && CLASSPATH=`cygpath --path --unix "$CLASSPATH"`
  [ -n "$JSSE_HOME" ] && JSSE_HOME=`cygpath --absolute --unix "$JSSE_HOME"`
fi

# For OS400
if $os400; then
  # Set job priority to standard for interactive (interactive - 6) by using
  # the interactive priority - 6, the helper threads that respond to requests
  # will be running at the same priority as interactive jobs.
  COMMAND='chgjob job('$JOBNAME') runpty(6)'
  system $COMMAND

  # Enable multi threading
  export QIBM_MULTI_THREADED=Y
fi

# Get standard Java environment variables
if $os400; then
  # -r will Only work on the os400 if the files are:
  # 1. owned by the user
  # 2. owned by the PRIMARY group of the user
  # this will not work if the user belongs in secondary groups
  BASEDIR="$CATALINA_HOME"
  . "$CATALINA_HOME"/bin/setclasspath.sh
else
#设定Classpath
  if [ -r "$CATALINA_HOME"/bin/setclasspath.sh ]; then
    BASEDIR="$CATALINA_HOME"
    . "$CATALINA_HOME"/bin/setclasspath.sh
  else
    echo "Cannot find $CATALINA_HOME/bin/setclasspath.sh"
    echo "This file is needed to run this program"
    exit 1
  fi
fi

# Add on extra jar files to CLASSPATH
if [ -n "$JSSE_HOME" ]; then
  CLASSPATH="$CLASSPATH":"$JSSE_HOME"/lib/jcert.jar:"$JSSE_HOME"/lib/jnet.jar:"$JSSE_HOME"/lib/jsse.jar
fi
CLASSPATH="$CLASSPATH":"$CATALINA_HOME"/bin/bootstrap.jar

#-z,字符串为空，设定Base = home
if [ -z "$CATALINA_BASE" ] ; then
  CATALINA_BASE="$CATALINA_HOME"
fi

#按默认值设定Temp 文件夹
if [ -z "$CATALINA_TMPDIR" ] ; then
  # Define the java.io.tmpdir to use for Catalina
  CATALINA_TMPDIR="$CATALINA_BASE"/temp
fi

# Bugzilla 37848: When no TTY is available, don't output to console
have_tty=0
if [ "`tty`" != "not a tty" ]; then
    have_tty=1
fi

# For Cygwin, switch paths to Windows format before running java
if $cygwin; then
  JAVA_HOME=`cygpath --absolute --windows "$JAVA_HOME"`
  JRE_HOME=`cygpath --absolute --windows "$JRE_HOME"`
  CATALINA_HOME=`cygpath --absolute --windows "$CATALINA_HOME"`
  CATALINA_BASE=`cygpath --absolute --windows "$CATALINA_BASE"`
  CATALINA_TMPDIR=`cygpath --absolute --windows "$CATALINA_TMPDIR"`
  CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
  [ -n "$JSSE_HOME" ] && JSSE_HOME=`cygpath --absolute --windows "$JSSE_HOME"`
  JAVA_ENDORSED_DIRS=`cygpath --path --windows "$JAVA_ENDORSED_DIRS"`
fi

# Set juli LogManager config file if it is present and an override has not been issued
#指定默认的Log 配置
if [ -z "$LOGGING_CONFIG" ]; then
  if [ -r "$CATALINA_BASE"/conf/logging.properties ]; then
    LOGGING_CONFIG="-Djava.util.logging.config.file=$CATALINA_BASE/conf/logging.properties"
  else
    # Bugzilla 45585
    LOGGING_CONFIG="-Dnop"
  fi
fi

#设定默认的日志管理器
if [ -z "$LOGGING_MANAGER" ]; then
  JAVA_OPTS="$JAVA_OPTS -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager"
else
  JAVA_OPTS="$JAVA_OPTS $LOGGING_MANAGER"
fi

# ----- Execute The Requested Command -----------------------------------------

# Bugzilla 37848: only output this if we have a TTY
if [ $have_tty -eq 1 ]; then
  echo "Using CATALINA_BASE:   $CATALINA_BASE"
  echo "Using CATALINA_HOME:   $CATALINA_HOME"
  echo "Using CATALINA_TMPDIR: $CATALINA_TMPDIR"
  if [ "$1" = "debug" -o "$1" = "javac" ] ; then
    echo "Using JAVA_HOME:       $JAVA_HOME"
  else
    echo "Using JRE_HOME:       $JRE_HOME"
  fi
fi

#接收参数
if [ "$1" = "jpda" ] ; then
  if [ -z "$JPDA_TRANSPORT" ]; then
    JPDA_TRANSPORT="dt_socket"
  fi
  if [ -z "$JPDA_ADDRESS" ]; then
    JPDA_ADDRESS="8000"
  fi
  if [ -z "$JPDA_SUSPEND" ]; then
    JPDA_SUSPEND="n"
  fi
  if [ -z "$JPDA_OPTS" ]; then
    JPDA_OPTS="-agentlib:jdwp=transport=$JPDA_TRANSPORT,address=$JPDA_ADDRESS,server=y,suspend=$JPDA_SUSPEND"
  fi
  CATALINA_OPTS="$CATALINA_OPTS $JPDA_OPTS"
  #shift 参数提升，即$2 变$1...
  shift
fi

if [ "$1" = "debug" ] ; then
  if $os400; then
    echo "Debug command not available on OS400"
    exit 1
  else
    shift
    if [ "$1" = "-security" ] ; then
      echo "Using Security Manager"
      shift
      exec "$_RUNJDB" "$LOGGING_CONFIG" $JAVA_OPTS $CATALINA_OPTS \
        -Djava.endorsed.dirs="$JAVA_ENDORSED_DIRS" -classpath "$CLASSPATH" \
        -sourcepath "$CATALINA_HOME"/../../java \
        -Djava.security.manager \
        -Djava.security.policy=="$CATALINA_BASE"/conf/catalina.policy \
        -Dcatalina.base="$CATALINA_BASE" \
        -Dcatalina.home="$CATALINA_HOME" \
        -Djava.io.tmpdir="$CATALINA_TMPDIR" \
        org.apache.catalina.startup.Bootstrap "$@" start
    else
      exec "$_RUNJDB" "$LOGGING_CONFIG" $JAVA_OPTS $CATALINA_OPTS \
        -Djava.endorsed.dirs="$JAVA_ENDORSED_DIRS" -classpath "$CLASSPATH" \
        -sourcepath "$CATALINA_HOME"/../../java \
        -Dcatalina.base="$CATALINA_BASE" \
        -Dcatalina.home="$CATALINA_HOME" \
        -Djava.io.tmpdir="$CATALINA_TMPDIR" \
        org.apache.catalina.startup.Bootstrap "$@" start
    fi
  fi

elif [ "$1" = "run" ]; then

  shift
  if [ "$1" = "-security" ] ; then
    echo "Using Security Manager"
    shift
    exec "$_RUNJAVA" "$LOGGING_CONFIG" $JAVA_OPTS $CATALINA_OPTS \
      -Djava.endorsed.dirs="$JAVA_ENDORSED_DIRS" -classpath "$CLASSPATH" \
      -Djava.security.manager \
      -Djava.security.policy=="$CATALINA_BASE"/conf/catalina.policy \
      -Dcatalina.base="$CATALINA_BASE" \
      -Dcatalina.home="$CATALINA_HOME" \
      -Djava.io.tmpdir="$CATALINA_TMPDIR" \
      org.apache.catalina.startup.Bootstrap "$@" start
  else
  #exec,执行指定的程序，$@ 代表所有的命令行参数
    exec "$_RUNJAVA" "$LOGGING_CONFIG" $JAVA_OPTS $CATALINA_OPTS \
      -Djava.endorsed.dirs="$JAVA_ENDORSED_DIRS" -classpath "$CLASSPATH" \
      -Dcatalina.base="$CATALINA_BASE" \
      -Dcatalina.home="$CATALINA_HOME" \
      -Djava.io.tmpdir="$CATALINA_TMPDIR" \
      org.apache.catalina.startup.Bootstrap "$@" start
  fi

elif [ "$1" = "start" ] ; then

  shift
  touch "$CATALINA_BASE"/logs/catalina.out
  if [ "$1" = "-security" ] ; then
    echo "Using Security Manager"
    shift
    "$_RUNJAVA" "$LOGGING_CONFIG" $JAVA_OPTS $CATALINA_OPTS \
      -Djava.endorsed.dirs="$JAVA_ENDORSED_DIRS" -classpath "$CLASSPATH" \
      -Djava.security.manager \
      -Djava.security.policy=="$CATALINA_BASE"/conf/catalina.policy \
      -Dcatalina.base="$CATALINA_BASE" \
      -Dcatalina.home="$CATALINA_HOME" \
      -Djava.io.tmpdir="$CATALINA_TMPDIR" \
      org.apache.catalina.startup.Bootstrap "$@" start \
      >> "$CATALINA_BASE"/logs/catalina.out 2>&1 &
#2>&1，将错误信息合并到标准输出
      if [ ! -z "$CATALINA_PID" ]; then
        echo $! > $CATALINA_PID
      fi
  else
    "$_RUNJAVA" "$LOGGING_CONFIG" $JAVA_OPTS $CATALINA_OPTS \
      -Djava.endorsed.dirs="$JAVA_ENDORSED_DIRS" -classpath "$CLASSPATH" \
      -Dcatalina.base="$CATALINA_BASE" \
      -Dcatalina.home="$CATALINA_HOME" \
      -Djava.io.tmpdir="$CATALINA_TMPDIR" \
      org.apache.catalina.startup.Bootstrap "$@" start \
      >> "$CATALINA_BASE"/logs/catalina.out 2>&1 &

      if [ ! -z "$CATALINA_PID" ]; then
      #将PID 记录到一个文件中，$$ 正在执行的PID,$! 后台运行的最后一个PID 值
        echo $! > $CATALINA_PID
      fi
  fi

elif [ "$1" = "stop" ] ; then

  shift
  FORCE=0
  if [ "$1" = "-force" ]; then
    shift
    FORCE=1
  fi

  "$_RUNJAVA" $JAVA_OPTS \
    -Djava.endorsed.dirs="$JAVA_ENDORSED_DIRS" -classpath "$CLASSPATH" \
    -Dcatalina.base="$CATALINA_BASE" \
    -Dcatalina.home="$CATALINA_HOME" \
    -Djava.io.tmpdir="$CATALINA_TMPDIR" \
    org.apache.catalina.startup.Bootstrap "$@" stop

  if [ $FORCE -eq 1 ]; then
    if [ ! -z "$CATALINA_PID" ]; then
       echo "Killing: `cat $CATALINA_PID`"
       kill -9 `cat $CATALINA_PID`
    else
       echo "Kill failed: \$CATALINA_PID not set"
    fi
  fi

elif [ "$1" = "version" ] ; then

    "$_RUNJAVA"   \
      -classpath "$CATALINA_HOME/lib/catalina.jar" \
      org.apache.catalina.util.ServerInfo

else
#打印一堆的帮助和错误信息
  echo "Usage: catalina.sh ( commands ... )"
  echo "commands:"
  if $os400; then
    echo "  debug             Start Catalina in a debugger (not available on OS400)"
    echo "  debug -security   Debug Catalina with a security manager (not available on OS400)"
  else
    echo "  debug             Start Catalina in a debugger"
    echo "  debug -security   Debug Catalina with a security manager"
  fi
  echo "  jpda start        Start Catalina under JPDA debugger"
  echo "  run               Start Catalina in the current window"
  echo "  run -security     Start in the current window with security manager"
  echo "  start             Start Catalina in a separate window"
  echo "  start -security   Start in a separate window with security manager"
  echo "  stop              Stop Catalina"
  echo "  stop -force       Stop Catalina (followed by kill -KILL)"
  echo "  version           What version of tomcat are you running?"
  exit 1

fi