suse nfs shell 解释

下面的解释可能有些不太准确，希望大家提出意见哈;我多修改，想对我自己总结知识也有帮助,所以贴出来
#! /bin/sh
# Copyright (c) 1996 - 2001 SuSE GmbH Nuernberg, Germany. All rights reserved.
#
# Author: Florian La Roche <florian@suse.de>, 1996
# 　　　Werner Fink <werner@suse.de>, 1996,98
# 　　　Burchard Steinbild <bs@suse.de>, 1997
# 　　　Thorsten Kukuk <kukuk@suse.de>, 2000,01
#
# /etc/init.d/nfsserver
#
### BEGIN INIT INFO
# Provides: nfsserver
# Required-Start: $network $remote_fs $named portmap
# Required-Stop: $network portmap
# Should-Start: ypbind svcgssd idmapd
# Should-Stop:
# Default-Start: 3 5
# Default-Stop: 0 1 2 6
# Description: Start the kernel based NFS daemon
### END INIT INFO
. /etc/sysconfig/nfs ＃执行/etc/sysconfig/nfs shell文件读取里面的变量设置
# Shell functions sourced from /etc/rc.status:
# 　　rc_check 　　　check and set local and overall rc status
# 　　rc_status 　　check and set local and overall rc status
# 　　rc_status -v 　ditto but be verbose in local rc status
# 　　rc_status -v -r ditto and clear the local rc status
# 　　rc_failed 　　set local and overall rc status to failed
# 　　rc_failed <num> set local and overall rc status to <num><num>
# 　　rc_reset 　　　clear local rc status (overall remains)
# 　　rc_exit 　　　exit appropriate to overall rc status
. /etc/rc.status 　＃上面是/etc/rc.status执行后的状态和变量初始化设置
# First reset status of this service
rc_reset 　 #首先清除本地一些主要rc.status的设置[page_break]
# Return values acc. to LSB for all commands but status:
# 0 - success
# 1 - generic or unspecifIEd error
# 2 - invalid or excess argument(s)
# 3 - unimplemented feature (e.g. "reload")
# 4 - insufficient privilege
# 5 - program is not installed
# 6 - program is not configured
# 7 - program is not running
#
# Note that starting an already running service, stopping
# or restarting a not-running service as well as the restart
# with force-reload (in case signalling is not supported) are
# considered a success.
case `uname -r` in
　0.*|1.*|2.0.*) exit 3 #判断内核是否是2.0.*以上就执行,否则就退出我的内核2.6.16.13-4-default
esac
check_for_nfsdfs() { 　　#设置check_for_nfsdfs()函数
　HAVE_NFSDFS="no" 　 ＃初始HAVE_NFSDFS为"no"
　while read dummy type ; do #循环从/proc/filesystems文件读取变量 type
　　if [ "$type" = "nfsd" ] ; then 　＃判断是否等于nfsd,
　　　　HAVE_NFSDFS="yes" ＃等于就设置HAVE_NFSDFS为yes
　　fi
　done < /proc/filesystems
}
case "$1" in 　 #变量$1读取第一个参数，然后判断是否启动，停止，重启等
　start)
　　PARAMS=3 　#设置PARAMS为3
　　test "$USE_KERNEL_NFSD_NUMBER" -gt 0 && PARAMS="$USE_KERNEL_NFSD_NUMBER" #测试USE_KERNEL_NFSD_NUMBER大于0 与PARAMS
　　　　　　　　　　　　　　＃等于USE_KERNEL_NFSD_NUMBER
　　echo -n "Starting kernel based NFS server" ＃显示开始NFS服务
　　modprobe nfsd 　　　 #内核加载NFS模块
　　check_for_nfsdfs 　 #调用check_for_nfsdfs函数
　　if [ "$HAVE_NFSDFS" = "yes" -a ! -f /proc/fs/nfsd/exports ] ; the 　　　 #判断HAVE_NFSDFS是否为yes 与 /proc/fs/nfsd/exports不存在且是普通文件
　　mount -t nfsd nfsd /proc/fs/nfsd ＃条件成立 mount /proc/fs/nfsd目录
　　rc_status 　＃调用/etc/rc.status设置本地的状态
　　fi
　　/usr/sbin/exportfs -r ＃修改nfs文件系统/var/lib/nfs/xtab 和 /etc/exports.同步
　　rc_status 　 ＃调用/etc/rc.status设置本地的状态
　　/usr/sbin/rpc.nfsd $PARAMS ＃注册rpc.nfsd行程连接
　　rc_status 　 ＃调用/etc/rc.status设置本地的状态
　　if [ -n "$MOUNTD_PORT" ] ; then ＃测试/etc/sysconfig/nfs文件的MOUNTD_PORT变量是否不为0
　　startproc /usr/sbin/rpc.mountd -p $MOUNTD_PORT #开始路径确定过程 且读取路径运行的pid
　　else
　　startproc /usr/sbin/rpc.mountd 　 #开始路径确定过程
　　fi
　　if [ "$NFS4_SUPPORT" = "yes" ]; then 　 #判断是否支持 NFSv4
　　checkproc /usr/sbin/rpc.idmapd #检查/usr/sbin/rpc.idmapd完整连接的过程
　　if [ $? -eq 0 ] ; then ＃判断/usr/sbin/rpc.idmapd完整连接的过程是否连接成功
　　　## Let idmapd know that nfs server is starting up
　　　/etc/init.d/idmapd reload
　　fi
　　fi
　　rc_status -v ＃调用/etc/rc.status设置本地的状态
　　;;
　stop)
　　echo -n "Shutting down kernel based NFS server" ＃显示关闭NFS服务
　　killproc -n -KILL nfsd ＃杀死nfsd相关的进程
　　rc_status ＃调用/etc/rc.status设置本地的状态
　　killproc 　-TERM /usr/sbin/rpc.mountd ＃杀死rpc.mountd相关的进程
　　rc_status
　　check_for_nfsdfs 　 #调用check_for_nfsdfs来设置HAVE_NFSDFS
　　if [ "$HAVE_NFSDFS" = "yes" -a -f /proc/fs/nfsd/exports ] ; then #判断HAVE_NFSDFS是否为yes 与 /proc/fs/nfsd/exports不存在且是普通文件
　　umount /proc/fs/nfsd 　 ＃条件成立 umount /proc/fs/nfsd目录
　　rc_status 　　　 ＃调用/etc/rc.status设置本地的状态
　　fi
　　rc_status -v
　　;;
　try-restart)
　　## Stop the service and if this succeeds (i.e. the
　　## service was running before), start it again.
　　$0 status >/dev/null && $0 restart #启动状态删除，然后重启
　　# Remember status and be quiet
　　rc_status
　　;;
　restart)
　　## Stop the service and regardless of whether it was
　　## running or not, start it again.
　　$0 stop
　　$0 start
　　# Remember status and be quiet
　　rc_status
　　;;
　reload|force-reload) #重新加载利用/etc/sysconfig/nfs的状态
　　echo -n "Reload kernel based NFS server"
　　/usr/sbin/exportfs -r
　　rc_status -v
　　;;
　status)
　　echo -n "Checking for kernel based NFS server: "
　　## Check status with checkproc(8), if process is running
　　## checkproc will return with exit status 0.
　　# Status has a slightly different for the status command:
　　# 0 - service running
　　# 1 - service dead, but /var/run/ pid file exists
　　# 2 - service dead, but /var/lock/ lock file exists
　　# 3 - service not running
　　# NOTE: checkproc returns LSB compliant status values.
　　checkproc /usr/sbin/rpc.mountd #检查/usr/sbin/rpc.idmapd完整连接的过程
　　rc_status 　　　 #利用/etc/sysconfig/nfs的状态
　　checkproc -n nfsd
　　rc_status -v
　　;;
　*)
　　echo "Usage: $0 {start|stop|status|try-restart|restart|force-reload|reload}" 　#否则显示相关启动的参数
　　exit 1
　　;;
esac
rc_exit