Shell如何创建进程树?

进入字符页面的 linux 进程的管理，如果需要用进程来强制关闭部分程序，那进程树的管理是必须掌握的！

下面是shell创建进程树的代码（此代码的作者ron peters）：

#!/bin/bash

#
# Display process table in tree form
#

if [ "$1" = "" ]
then
  proc=1
else
  proc=$1
fi

main () {

PSOUT=`ps -ef | grep -v "^UID" | sort -n -k2`
# This technique will work in ksh, but since there are going to be array
# subscripts larger than 1024, bash is the way to go.
#ps -ef | grep -v "^UID" | while read line
while read line
do
  line=`echo "$line" | sed -e s/\>/\\\\\\>/g`
  #echo $line
  # works in ksh/pdksh as long as the subscript is below 1024.. here it is not
  # bash works fine though.
  #set -A process $line for a ksh script
  declare -a process=( $line )
  pid=${process[1]}
  owner[$pid]=${process[0]}
  ppid[$pid]=${process[2]}
  command[$pid]="`echo $line | awk '{for(i=8;i<=NF;i++) {printf "%s ",$i}}'`"
#此处算法，通过的父pid来定位，巧用 good!
children[${ppid[$pid]}]="${children[${ppid[$pid]}]} $pid"
done <<EOF
$PSOUT
EOF

# something about the arrays is that the values seem to be only good in the
# above loop. This is a known issue with bash that all the piped elements
# are in subshells and their variables aren't available to the parent shell.
# Take the pipe out of the equation and send it to a file, then redirect
# the file into the end of the while loop.
print_tree $proc ""

}

print_tree () {

id=$1

echo "$2$id" ${owner[$id]} ${command[$id]}

if [ "${children[$id]}" = "" ]
then
return
else
for child in ${children[$id]}
do
if [ "$child" = "`echo ${children[${ppid[$child]}]} | awk '{print $NF}'`" ]
then
echo "$2 \\"
temp="$2 "
else
echo "$2|\\"
temp="$2| "
fi
print_tree $child "$temp"
done
fi

}

main

运行结果(部分树结构 可传入指定ID打印该进程树）：

1 root init [5]
|\
|  2 root [migration/0]
|\
|  3 root [ksoftirqd/0]
|\
|  4 root [watchdog/0]
|\
|  5 root [migration/1]
|\
|  6 root [ksoftirqd/1]
|\
|  7 root [watchdog/1]
|\
|  8 root [migration/2]
|\
|  9 root [ksoftirqd/2]
|\
|  10 root [watchdog/2]
|\
|  11 root [migration/3]

本文出自 “凹凸曼” 博客，请务必保留此出处 http://www.apoyl.com/?p=1118