Tomcat 的启动文件 catalina.sh shell脚本详解

接上一篇文章：我们启动tomcat下的start.sh文件，shell脚本到底做了什么呢？在上一篇文章最后，start.sh 最终调用了 catalina.sh 脚本（调用命令为：exec /usr/local/apache-tomcat-9.0.21/bin/catalina.sh start "$@"）；那么catalina.sh 具体干了什么呢？

代码块：

# OS specific support.  $var _must_ be set to either true or false.
cygwin=false
darwin=false
os400=false
hpux=false
case "`uname`" in
CYGWIN*) cygwin=true;;
Darwin*) darwin=true;;
OS400*) os400=true;;
HP-UX*) hpux=true;;
esac
resolve links - $0 may be a softlink
PRG="$0"
while [ -h "$PRG" ]; do
 ls=ls -ld "$PRG"
 link=expr "$ls" : '.*-> \(.*\)$'
 if expr "$link" : '/.*' > /dev/null; then
 PRG="$link"
 else
 PRG=dirname "$PRG"/"$link"
 fi
 done

    
    
   
   

   
   
  
  

上述这一段代码，设定了一些变量， 并通过case判断根据服务器操作系统的不同，设置不同的参数值。通过while循环判断，获取catalina.sh的绝对路径（非链接），赋值给PRG。在服务器上执行uname为Linux。比如我的tomcat的catalina.sh的绝对路径为/usr/local/apache-tomcat-9.0.21/bin/catalina.sh。此时，变量情况为：

cygwin=false
darwin=false
os400=false
hpux=false
PRG=/usr/local/apache-tomcat-9.0.21/bin/catalina.sh

    
    
   
   

   
   
  
  

代码块：

# Only set CATALINA_HOME if not already set
[ -z "$CATALINA_HOME" ] && CATALINA_HOME=`cd "$PRGDIR/.." >/dev/null; pwd`
Copy CATALINA_BASE from CATALINA_HOME if not already set
[ -z "$CATALINA_BASE" ] && CATALINA_BASE="$CATALINA_HOME"
Ensure that any user defined CLASSPATH variables are not used on startup,
but allow them to be specified in setenv.sh, in rare case when it is needed.
CLASSPATH=
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

    
    
   
   

   
   
  
  

上述代码，通过-z判断变量CATALINA_HOME与CATALINA_BASE是否已经设置；若未设置，则设定默认值。默认情况下，bin目录下默认是没有setenv.sh文件。所以上述代码执行后，变量变动情况如下：

PRGDIR=/usr/local/apache-tomcat-9.0.21/bin
CATALINA_HOME=/usr/local/apache-tomcat-9.0.21
CATALINA_BASE=/usr/local/apache-tomcat-9.0.21
CLASSPATH=

    
    
   
   

   
   
  
  

代码块：

# 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"`
fi
Ensure that neither CATALINA_HOME nor CATALINA_BASE contains a colon
as this is used as the separator in the classpath and Java provides no
mechanism for escaping if the same character appears in the path.
case $CATALINA_HOME in
 :) echo "Using CATALINA_HOME: $CATALINA_HOME";
 echo "Unable to start as CATALINA_HOME contains a colon (😃 character";
 exit 1;
 esac
 case $CATALINA_BASE in
 :) echo "Using CATALINA_BASE: $CATALINA_BASE";
 echo "Unable to start as CATALINA_BASE contains a colon (😃 character";
 exit 1;
 esac

    
    
   
   

   
   
  
  

上述代码，由于$cygwin=false，跳过if判断。接下来两个case通过$CATALINA_HOME与$CATALINA_BASE的值是否包含：判断服务器是否设置了环境变量。若系统设置的环境变量，会给出提示，并退出执行脚本。由于服务器没有CATALINA的环境变量设置，故此时无变量变化。
代码块：

# 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 $os400; then
-r will Only work on the os400 if the files are:
1. owned by the user
2. owned by the PRIMARY group of the user
this will not work if the user belongs in secondary groups
. "$CATALINA_HOME"/bin/setclasspath.sh
 else
 if [ -r "$CATALINA_HOME"/bin/setclasspath.sh ]; then
 . "$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

    
    
   
   

   
   
  
  

由于$os400=false，所以第一段if...else...跳过，第二段if...else...进入else 。当setclasspath.sh文件可读时，执行该文件，否则给出提示，并退出脚本。
注：关于setclasspath.sh到底在干嘛，我们下次再详述。 此时变量无变化。
代码块：

# Add on extra jar files to CLASSPATH
if [ ! -z "$CLASSPATH" ] ; then
  CLASSPATH="$CLASSPATH":
fi
CLASSPATH="$CLASSPATH""$CATALINA_HOME"/bin/bootstrap.jar
if [ -z "$CATALINA_OUT" ] ; then
 CATALINA_OUT="$CATALINA_BASE"/logs/catalina.out
 fi
if [ -z "$CATALINA_TMPDIR" ] ; then
Define the java.io.tmpdir to use for Catalina
CATALINA_TMPDIR="$CATALINA_BASE"/temp
 fi
Add tomcat-juli.jar to classpath
tomcat-juli.jar can be over-ridden per instance
if [ -r "$CATALINA_BASE/bin/tomcat-juli.jar" ] ; then
 CLASSPATH=$CLASSPATH:$CATALINA_BASE/bin/tomcat-juli.jar
 else
 CLASSPATH=$CLASSPATH:$CATALINA_HOME/bin/tomcat-juli.jar
 fi

    
    
   
   

   
   
  
  

上述代码，对一些变量进行简单的判断，根据情况赋值，此时变量变化情况为：

CLASSPATH= --> /usr/local/apache-tomcat-9.0.21/bin/bootstrap.jar
CATALINA_OUT=/usr/local/apache-tomcat-9.0.21/logs/catalina.out
CATALINA_TMPDIR=/usr/local/apache-tomcat-9.0.21/temp
CLASSPATH=/usr/local/apache-tomcat-9.0.21/bin/bootstrap.jar --> /usr/local/apache-tomcat-9.0.21/bin/bootstrap.jar:/usr/local/apache-tomcat-9.0.21/bin/tomcat-juli.jar

    
    
   
   

   
   
  
  

代码块：

# Bugzilla 37848: When no TTY is available, don't output to console
have_tty=0
if [ -t 1 ]; 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 "$CLASSPATH"
 [ -n "$JAVA_ENDORSED_DIRS" ] && JAVA_ENDORSED_DIRS=cygpath --path --windows "$JAVA_ENDORSED_DIRS"
 fi
if [ -z "$JSSE_OPTS" ] ; then
 JSSE_OPTS="-Djdk.tls.ephemeralDHKeySize=2048"
 fi
 JAVA_OPTS="$JAVA_OPTS $JSSE_OPTS"
Register custom URL handlers
Do this here so custom URL handles (specifically 'war:...') can be used in the security policy
JAVA_OPTS="$JAVA_OPTS -Djava.protocol.handler.pkgs=org.apache.catalina.webresources"
Set juli LogManager config file if it is present and an override has not been issued
if [ -z "$LOGGING_CONFIG" ]; then
 if [ -r "$CATALINA_BASE"/conf/logging.properties ]; then
 LOGGING_CONFIG="-Djava.util.logging.config.file=$CATALINA_BASE/conf/logging.properties"
 else
 # Bugzilla 45585
 LOGGING_CONFIG="-Dnop"
 fi
 fi
if [ -z "$LOGGING_MANAGER" ]; then
 LOGGING_MANAGER="-Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager"
 fi
Set UMASK unless it has been overridden
if [ -z "$UMASK" ]; then
 UMASK="0027"
 fi
 umask $UMASK

    
    
   
   

   
   
  
  

上述代码， [ -t 1 ]=true, $cygwin=false，而后是一些变量的判断。此时变量的变化为：

have_tty=1
JSSE_OPTS="-Djdk.tls.ephemeralDHKeySize=2048"
JAVA_OPTS="-Djdk.tls.ephemeralDHKeySize=2048"
JAVA_OPTS="-Djdk.tls.ephemeralDHKeySize=2048 -Djava.protocol.handler.pkgs=org.apache.catalina.webresources"
LOGGING_CONFIG="-Djava.util.logging.config.file=/usr/local/apache-tomcat-9.0.21/conf/logging.properties"
LOGGING_MANAGER="-Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager"
UMASK="0027"

    
    
   
   

   
   
  
  

代码块：

# Java 9 no longer supports the java.endorsed.dirs
# system property. Only try to use it if
# JAVA_ENDORSED_DIRS was explicitly set
# or CATALINA_HOME/endorsed exists.
ENDORSED_PROP=ignore.endorsed.dirs
if [ -n "$JAVA_ENDORSED_DIRS" ]; then
    ENDORSED_PROP=java.endorsed.dirs
fi
if [ -d "$CATALINA_HOME/endorsed" ]; then
    ENDORSED_PROP=java.endorsed.dirs
fi
Make the umask available when using the org.apache.catalina.security.SecurityListener
JAVA_OPTS="$JAVA_OPTS -Dorg.apache.catalina.security.SecurityListener.UMASK=umask"
if [ -z "$USE_NOHUP" ]; then
 if $hpux; then
 USE_NOHUP="true"
 else
 USE_NOHUP="false"
 fi
 fi
 unset _NOHUP
 if [ "$USE_NOHUP" = "true" ]; then
 _NOHUP="nohup"
 fi
Add the JAVA 9 specific start-up parameters required by Tomcat
JDK_JAVA_OPTIONS="$JDK_JAVA_OPTIONS --add-opens=java.base/java.lang=ALL-UNNAMED"
 JDK_JAVA_OPTIONS="$JDK_JAVA_OPTIONS --add-opens=java.base/java.io=ALL-UNNAMED"
 JDK_JAVA_OPTIONS="$JDK_JAVA_OPTIONS --add-opens=java.rmi/sun.rmi.transport=ALL-UNNAMED"
 export JDK_JAVA_OPTIONS

    
    
   
   

   
   
  
  

上述代码，[ -n "$JAVA_ENDORSED_DIRS" ]=falase, [ -d "$CATALINA_HOME/endorsed" ]=false， [ -z "$USE_NOHUP" ]=true，，此时变量变化如下：

JAVA_OPTS="-Djdk.tls.ephemeralDHKeySize=2048 -Djava.protocol.handler.pkgs=org.apache.catalina.webresources -Dorg.apache.catalina.security.SecurityListener.UMASK=0027"
USE_NOHUP="false"
JDK_JAVA_OPTIONS="--add-opens=java.base/java.lang=ALL-UNNAMED"
JDK_JAVA_OPTIONS="--add-opens=java.base/java.io=ALL-UNNAMED"
JDK_JAVA_OPTIONS="--add-opens=java.rmi/sun.rmi.transport=ALL-UNNAMED"

    
    
   
   

   
   
  
  

代码块：

# ----- 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" ] ; then
 echo "Using JAVA_HOME: $JAVA_HOME"
 else
 echo "Using JRE_HOME: $JRE_HOME"
 fi
 echo "Using CLASSPATH: $CLASSPATH"
 if [ ! -z "$CATALINA_PID" ]; then
 echo "Using CATALINA_PID: $CATALINA_PID"
 fi
 fi

    
    
   
   

   
   
  
  

上述代码没有做什么操作，只是打印了一些信息而已。
调用此脚本的外部参数为start，故下述只看 [ $1 = start ]的代码块：

if [ "$1" = "jpda" ] ; then
略
fi
if [ "$1" = "debug" ] ; then
略
elif [ "$1" = "run" ]; then
略
elif [ "$1" = "start" ] ; then
if [ ! -z "$CATALINA_PID" ]; then
 if [ -f "$CATALINA_PID" ]; then
 if [ -s "$CATALINA_PID" ]; then
 echo "Existing PID file found during start."
 if [ -r "$CATALINA_PID" ]; then
 PID=cat "$CATALINA_PID"
 ps -p $PID >/dev/null 2>&1
 if [ $? -eq 0 ] ; then
 echo "Tomcat appears to still be running with PID $PID. Start aborted."
 echo "If the following process is not a Tomcat process, remove the PID file and try again:"
 ps -f -p $PID
 exit 1
 else
 echo "Removing/clearing stale PID file."
 rm -f "$CATALINA_PID" >/dev/null 2>&1
 if [ $? != 0 ]; then
 if [ -w "$CATALINA_PID" ]; then
 cat /dev/null > "$CATALINA_PID"
 else
 echo "Unable to remove or clear stale PID file. Start aborted."
 exit 1
 fi
 fi
 fi
 else
 echo "Unable to read PID file. Start aborted."
 exit 1
 fi
 else
 rm -f "$CATALINA_PID" >/dev/null 2>&1
 if [ $? != 0 ]; then
 if [ ! -w "$CATALINA_PID" ]; then
 echo "Unable to remove or write to empty PID file. Start aborted."
 exit 1
 fi
 fi
 fi
 fi
 fi
shift
 touch "$CATALINA_OUT"
 if [ "$1" = "-security" ] ; then
 if [ $have_tty -eq 1 ]; then
 echo "Using Security Manager"
 fi
 shift
 eval $_NOHUP ""$_RUNJAVA"" ""$LOGGING_CONFIG"" $LOGGING_MANAGER $JAVA_OPTS $CATALINA_OPTS 
 -D$ENDORSED_PROP=""$JAVA_ENDORSED_DIRS"" 
 -classpath ""$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_OUT" 2>&1 "&"
else
 eval $_NOHUP ""$_RUNJAVA"" ""$LOGGING_CONFIG"" $LOGGING_MANAGER $JAVA_OPTS $CATALINA_OPTS 
 -D$ENDORSED_PROP=""$JAVA_ENDORSED_DIRS"" 
 -classpath ""$CLASSPATH"" 
 -Dcatalina.base=""$CATALINA_BASE"" 
 -Dcatalina.home=""$CATALINA_HOME"" 
 -Djava.io.tmpdir=""$CATALINA_TMPDIR"" 
 org.apache.catalina.startup.Bootstrap "$@" start 
 >> "$CATALINA_OUT" 2>&1 "&"
fi
if [ ! -z "$CATALINA_PID" ]; then
 echo $! > "$CATALINA_PID"
 fi
echo "Tomcat started."
 elif [ "$1" = "stop" ] ; then
 略
 elif [ "$1" = "configtest" ] ; then
 略
 elif [ "$1" = "version" ] ; then
 略
 else
 略
 fi

    
    
   
   

   
   
  
  

上述非start外部传参的判断条件省略了。[ "$1" = "start" ]=true, [ ! -z "$CATALINA_PID" ]=false，此时代码走到 shift这里，由于只有一个外部传参start,故 [ "$1" = "-security" ]=false，此时进入 else 分支，执行下述命令：

 eval $_NOHUP "\"$_RUNJAVA\"" "\"$LOGGING_CONFIG\"" $LOGGING_MANAGER $JAVA_OPTS $CATALINA_OPTS \
      -D$ENDORSED_PROP="\"$JAVA_ENDORSED_DIRS\"" \
      -classpath "\"$CLASSPATH\"" \
      -Dcatalina.base="\"$CATALINA_BASE\"" \
      -Dcatalina.home="\"$CATALINA_HOME\"" \
      -Djava.io.tmpdir="\"$CATALINA_TMPDIR\"" \
      org.apache.catalina.startup.Bootstrap "$@" start \
      >> "$CATALINA_OUT" 2>&1 "&"
注：从setclasspath.sh得变量
_RUNJAVA=/usr/java/jdk1.8.0_91/bin/java
_RUNJDB=/usr/java/jdk1.8.0_91/bin/jdb
上述命令，将变量替换掉，为：
/usr/java/jdk1.8.0_91/bin/java
 -Djava.util.logging.config.file=/usr/local/apache-tomcat-9.0.21/conf/logging.properties\
 -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager
 -Djdk.tls.ephemeralDHKeySize=2048 -Djava.protocol.handler.pkgs=org.apache.catalina.webresources -Dorg.apache.catalina.security.SecurityListener.UMASK=0027 
 -D$ENDORSED_PROP=
 -classpath /usr/local/apache-tomcat-9.0.21/bin/bootstrap.jar:/usr/local/apache-tomcat-9.0.21/bin/tomcat-juli.jar
 -Dcatalina.base=/usr/local/apache-tomcat-9.0.21 
 -Dcatalina.home=/usr/local/apache-tomcat-9.0.21 
 -Djava.io.tmpdir=/usr/local/apache-tomcat-9.0.21/temp 
 org.apache.catalina.startup.Bootstrap start 
 >> /usr/local/apache-tomcat-9.0.21/logs/catalina.out 2>&1 &

    
    
   
   

   
   
  
  

所以tomcat执行start.sh 脚本时，通常情况下 就是上述这么一个命令。你可以直接在命令行执行此命令：

[root@test-cdh conf]# /usr/java/jdk1.8.0_91/bin/java -Djava.util.logging.config.file=/usr/local/apache-tomcat-9.0.21/conf/logging.properties -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djdk.tls.ephemeralDHKeySize=2048 -Djava.protocol.handler.pkgs=org.apache.catalina.webresources -Dorg.apache.catalina.security.SecurityListener.UMASK=0027 -D= -classpath /usr/local/apache-tomcat-9.0.21/bin/bootstrap.jar:/usr/local/apache-tomcat-9.0.21/bin/tomcat-juli.jar -Dcatalina.base=/usr/local/apache-tomcat-9.0.21 -Dcatalina.home=/usr/local/apache-tomcat-9.0.21 -Djava.io.tmpdir=/usr/local/apache-tomcat-9.0.21/temp org.apache.catalina.startup.Bootstrap start >> /usr/local/apache-tomcat-9.0.21/logs/catalina.out 2>&1 &
[1] 49852

    
    
   
   

   
   
  
  

现在是不是觉得，写的很复杂的脚本，只是一条有较多java参数的命令而已，是不是顿时豁然开朗。

附：上述有很多判断的语句，有一博文整理了，如下（链接为：https://blog.csdn.net/weixin_30367873/article/details/95135922）：

运算符	描述	示例
文件比较运算符
-e filename	如果 filename 存在，则为真	[ -e /var/log/syslog ]
-d filename	如果 filename 为目录，则为真	[ -d /tmp/mydir ]
-f filename	如果 filename 为常规文件，则为真	[ -f /usr/bin/grep ]
-L filename	如果 filename 为符号链接，则为真	[ -L /usr/bin/grep ]
-r filename	如果 filename 可读，则为真	[ -r /var/log/syslog ]
-w filename	如果 filename 可写，则为真	[ -w /var/mytmp.txt ]
-x filename	如果 filename 可执行，则为真	[ -L /usr/bin/grep ]
filename1 -nt filename2	如果 filename1 比 filename2 新，则为真	[ /tmp/install/etc/services -nt /etc/services ]
filename1 -ot filename2	如果 filename1 比 filename2 旧，则为真	[ /boot/bzImage -ot arch/i386/boot/bzImage ]
字符串比较运算符 （请注意引号的使用，这是防止空格扰乱代码的好方法）
-z string	如果 string 长度为零，则为真	[ -z "$myvar" ]
-n string	如果 string 长度非零，则为真	[ -n "$myvar" ]
string1 = string2	如果 string1 与 string2 相同，则为真	[ "$myvar" = "one two three" ]
string1 != string2	如果 string1 与 string2 不同，则为真	[ "$myvar" != "one two three" ]
算术比较运算符
num1 -eq num2	等于	[ 3 -eq $mynum ]
num1 -ne num2	不等于	[ 3 -ne $mynum ]
num1 -lt num2	小于	[ 3 -lt $mynum ]
num1 -le num2	小于或等于	[ 3 -le $mynum ]
num1 -gt num2	大于	[ 3 -gt $mynum ]
num1 -ge num2	大于或等于	[ 3 -ge $mynum ]

    
    
   
   

   
   
  
  

出处：https://blog.csdn.net/ck3207/article/details/100932690