之所以分析setclasspath.sh脚本，是因为catalina.sh脚本会引用到这个脚本，如果不对其进行分析，之后看catalina.sh脚本就会不知道一些变量没有申明和赋值怎么会跑出来，本篇文章是为下一篇“tomcat运行控制脚本catalina.sh分析”做铺垫。
#!/bin/sh # Licensed to the Apache Software Foundation (ASF) under one or more # contributor license agreements. See the NOTICE file distributed with # this work for additional information regarding copyright ownership. # The ASF licenses this file to You under the Apache License, Version 2.0 # (the "License"); you may not use this file except in compliance with # the License. You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. # ----------------------------------------------------------------------------- # Set CLASSPATH and Java options # # $Id: setclasspath.sh 795037 2009-07-17 10:52:16Z markt $ # ----------------------------------------------------------------------------- # Make sure prerequisite environment variables are set #因为setclasspath.sh脚本是被catalina.sh调用，所以可以继承catalina.sh中的变量申明 if [ -z "$JAVA_HOME" -a -z "$JRE_HOME" ]; then #判断用户有没有提前做$JAVA_HOME和$JRE_HOME全局变量声明，如果都没进行申明 # Bugzilla 37284 (reviewed). if $darwin; then #这个是win仿真unix不用管下面两个语句 if [ -d "/System/Library/Frameworks/JavaVM.framework/Versions/CurrentJDK/Home" ]; then export JAVA_HOME="/System/Library/Frameworks/JavaVM.framework/Versions/CurrentJDK/Home" fi else #其他环境没有申明，那么系统自己想办法找这两个变量的路径 JAVA_PATH=`which java 2>/dev/null` #此语句可以把java命令位置找出来 if [ "x$JAVA_PATH" != "x" ]; then #如果能找出java路径，则可以定位到java命令的路径，经过作者验证不是java的装路径 #所以通过此处就可以看出，老鸟们为什么都要自己指定这两个变量了 JAVA_PATH=`dirname $JAVA_PATH 2>/dev/null` JRE_HOME=`dirname $JAVA_PATH 2>/dev/null` fi if [ "x$JRE_HOME" = "x" ]; then #如果找不到java路径，那么就看有没有/usr/bin/java这个执行文件，有的话就它了，没有就算了 # XXX: Should we try other locations? if [ -x /usr/bin/java ]; then JRE_HOME=/usr fi fi fi if [ -z "$JAVA_HOME" -a -z "$JRE_HOME" ]; then #再验证一边，有没有这两个变量，没有不好意思，我不执行了，退出 #这个exit 1 不但是结束setclasspath.sh，会彻底退出catalina.sh脚本的 #对于在脚本中引用脚本的童鞋们，就需要注意了，小心使用exit。 echo "Neither the JAVA_HOME nor the JRE_HOME environment variable is defined" echo "At least one of these environment variable is needed to run this program" exit 1 fi fi if [ -z "$JAVA_HOME" -a "$1" = "debug" ]; then echo "JAVA_HOME should point to a JDK in order to run in debug mode." exit 1 fi if [ -z "$JRE_HOME" ]; then JRE_HOME="$JAVA_HOME" fi # If we‘re running under jdb, we need a full jdk. if [ "$1" = "debug" ] ; then if [ "$os400" = "true" ]; then if [ ! -x "$JAVA_HOME"/bin/java -o ! -x "$JAVA_HOME"/bin/javac ]; then echo "The JAVA_HOME environment variable is not defined correctly" echo "This environment variable is needed to run this program" echo "NB: JAVA_HOME should point to a JDK not a JRE" exit 1 fi else if [ ! -x "$JAVA_HOME"/bin/java -o ! -x "$JAVA_HOME"/bin/jdb -o ! -x "$JAVA_HOME"/bin/javac ]; then echo "The JAVA_HOME environment variable is not defined correctly" echo "This environment variable is needed to run this program" echo "NB: JAVA_HOME should point to a JDK not a JRE" exit 1 fi fi fi #上段的代码都是在确认$JAVA_HOME和$JRE_HOME变量的申明情况及后续的解决过程 if [ -z "$BASEDIR" ]; then #对"$BASEDIR变量的检查，木有的话就退出 echo "The BASEDIR environment variable is not defined" echo "This environment variable is needed to run this program" exit 1 fi if [ ! -x "$BASEDIR"/bin/setclasspath.sh ]; then #确认"$BASEDIR"/bin/setclasspath.sh有木有，木有还是退出 if $os400; then # -x will Only work on the os400 if the files are: # 1. owned by the user # 2. owned by the PRIMARY group of the user # this will not work if the user belongs in secondary groups eval #eval不清楚嘛意思 else echo "The BASEDIR environment variable is not defined correctly" echo "This environment variable is needed to run this program" exit 1 fi fi # Don‘t override the endorsed dir if the user has set it previously #这个是确认JAVA_ENDORSED_DIRS的位置 if [ -z "$JAVA_ENDORSED_DIRS" ]; then # Set the default -Djava.endorsed.dirs argument JAVA_ENDORSED_DIRS="$BASEDIR"/endorsed fi # OSX hack to CLASSPATH JIKESPATH= if [ `uname -s` = "Darwin" ]; then OSXHACK="/System/Library/Frameworks/JavaVM.framework/Versions/CurrentJDK/Classes" if [ -d "$OSXHACK" ]; then for i in "$OSXHACK"/*.jar; do JIKESPATH="$JIKESPATH":"$i" done fi fi # Set standard commands for invoking Java. #这句是响当当的重要，确定了$_RUNJAVA的值 _RUNJAVA="$JRE_HOME"/bin/java if [ "$os400" != "true" ]; then _RUNJDB="$JAVA_HOME"/bin/jdb fi
通过脚本分析，我们就看到，这个脚本就做了一件事情，检查各种变量是否赋值，验证tomcat启动停止需要涉及到的文件，保障tomcat顺利启动停止。
时间： 2024-08-28 22:23:26