功能说明：以树状图显示程序。
语 法：pstree [-acGhlnpuUV][-H <程序识别码>][<程序识别码>/<用户名称>]
补充说明：pstree指令用ASCII字符显示树状结构，清楚地表达程序间的相互关系。如果不指定程序识别码或用户名称，则会把系统启动时的第一个程序视为基层，并显示之后的所有程序。若指定用户名称，便会以隶属该用户的第一个程序当作基层，然后显示该用户的所有程序。
参 数：
-a 显示每个程序的完整指令，包含路径，参数或是常驻服务的标示。
-c 不使用精简标示法。
-G 使用VT100终端机的列绘图字符。
-h 列出树状图时，特别标明现在执行的程序。
-H<程序识别码> 此参数的效果和指定"-h"参数类似，但特别标明指定的程序。
-l 采用长列格式显示树状图。
-n 用程序识别码排序。预设是以程序名称来排序。
-p 显示程序识别码。
-u 显示用户名称。
-U 使用UTF-8列绘图字符。
-V 显示版本信息。
再补充：
说明：将所有行程以树状图显示, 树状图将会以 pid (如果有指定) 或是以 init 这个基本行程为根 (root) ,如果有指定使用者 id , 则树状图会只显示该使用者所拥有的行程
参数：
-a 显示该行程的完整指令及参数, 如果是被记忆体置换出去的行程则会加上括号
-c 如果有重覆的行程名, 则分开列出 (预设值是会在前面加上 *)
示例：
1 使用pstree命令结果：
pstree
init-+-bscpserver
|-crond
|-dbproxy---2*[dbproxy]
|-dbus-daemon-1
|-events/0-+-aio/0
| |-aio/1
| |-aio/2
| |-aio/3
| |-aio/4
| |-aio/5
| |-aio/6
| |-aio/7
| |-ata/0
| |-ata/1
| |-ata/2
| |-ata/3
| |-ata/4
| |-ata/5
| |-ata/6
| |-ata/7
| |-kacpid
| |-kauditd
| |-kblockd/0
| |-kblockd/1
| |-kblockd/2
| |-kblockd/3
| |-kblockd/4
| |-kblockd/5
| |-kblockd/6
| |-kblockd/7
| |-khelper
| |-kmir_mon
| |-kmirrord
| `-2*[pdflush]
|-events/1
|-events/2
|-events/3
|-events/4
|-events/5
|-events/6
|-events/7
|-khubd
|-klogd
|-kseriod
|-ksoftirqd/0
|-ksoftirqd/1
|-ksoftirqd/2
|-ksoftirqd/3
|-ksoftirqd/4
|-ksoftirqd/5
|-ksoftirqd/6
|-ksoftirqd/7
|-kswapd0
|-2*[lighttpd-+-2*[cronolog]]
| `-5*[{lighttpd}]]
|-migration/0
|-migration/1
|-migration/2
|-migration/3
|-migration/4
|-migration/5
|-migration/6
|-migration/7
|-6*[mingetty]
|-mysqld_safe---mysqld---17*[{mysqld}]
|-php---sh---php
|-portmap
|-6*[screen---bash]
|-screen---bash---screen
|-screen---2*[bash]
|-shpchpd_event
|-2*[ssh]
|-sshd-+-sshd---sshd---bash---mysql
| |-3*[sshd---sshd---bash]
| |-2*[sshd---sshd---bash---bash---ssh]
| `-sshd---sshd---bash---pstree
|-supervise---proftpd
|-supervise.agent---noah-agent---noah-agent64-+-noah-agent64---27*[{noah-agent64}]
| `-supercpum64
|-supervise.bscpl---bscplimitr
|-supervise.drct---drct---27*[{drct}]
|-supervise.ocage---open_vmstat
|-supervise.ocage---open_iostat
|-supervise.ocage---oc_python
|-syslogd
|-tinyproxy---79*[tinyproxy]
|-udevd
|-2*[vim]
|-vmstat
`-xinetd
2 使用pstree加p参数结果
pstree -p
init(1)-+-bscpserver(27694)
|-crond(2240)
|-dbproxy(23477)-+-dbproxy(23481)
| `-dbproxy(23482)
|-dbus-daemon-1(2249)
|-events/0(18)-+-aio/0(116)
| |-aio/1(117)
| |-aio/2(118)
| |-aio/3(119)
| |-aio/4(120)
| |-aio/5(121)
| |-aio/6(122)
| |-aio/7(123)
| |-ata/0(275)
| |-ata/1(276)
| |-ata/2(277)
| |-ata/3(278)
| |-ata/4(279)
| |-ata/5(280)
| |-ata/6(281)
| |-ata/7(282)
| |-kacpid(27)
| |-kauditd(1632)
| |-kblockd/0(87)
| |-kblockd/1(88)
| |-kblockd/2(89)
| |-kblockd/3(90)
| |-kblockd/4(91)
| |-kblockd/5(92)
| |-kblockd/6(93)
| |-kblockd/7(94)
| |-khelper(26)
| |-kmir_mon(1845)
| |-kmirrord(1844)
| |-pdflush(19159)
| `-pdflush(4673)
|-events/1(19)
|-events/2(20)
|-events/3(21)
|-events/4(22)
|-events/5(23)
|-events/6(24)
|-events/7(25)
|-khubd(95)
|-klogd(3897)
|-kseriod(196)
|-ksoftirqd/0(3)
|-ksoftirqd/1(5)
|-ksoftirqd/2(7)
|-ksoftirqd/3(9)
|-ksoftirqd/4(11)
|-ksoftirqd/5(13)
|-ksoftirqd/6(15)
|-ksoftirqd/7(17)
|-kswapd0(115)
|-lighttpd(17792)-+-cronolog(17793)
| |-cronolog(17794)
| |-{lighttpd}(17795)
| |-{lighttpd}(17796)
| |-{lighttpd}(17797)
| |-{lighttpd}(17798)
| `-{lighttpd}(17799)
|-lighttpd(5265)-+-cronolog(5274)
| |-cronolog(5275)
| |-{lighttpd}(5276)
| |-{lighttpd}(5277)
| |-{lighttpd}(5278)
| |-{lighttpd}(5279)
| `-{lighttpd}(5280)
|-migration/0(2)
|-migration/1(4)
|-migration/2(6)
|-migration/3(8)
|-migration/4(10)
|-migration/5(12)
|-migration/6(14)
|-migration/7(16)
|-mingetty(3905)
|-mingetty(3907)
|-mingetty(3908)
|-mingetty(3909)
|-mingetty(3910)
|-mingetty(3911)
|-mysqld_safe(6146)---mysqld(6331)-+-{mysqld}(6335)
| |-{mysqld}(6336)
| |-{mysqld}(6337)
| |-{mysqld}(6338)
| |-{mysqld}(6357)
| |-{mysqld}(6358)
| |-{mysqld}(6359)
| |-{mysqld}(6360)
| |-{mysqld}(18770)
| |-{mysqld}(19006)
| |-{mysqld}(20000)
| |-{mysqld}(20004)
| |-{mysqld}(31148)
| |-{mysqld}(21640)
| |-{mysqld}(15041)
| |-{mysqld}(8296)
| `-{mysqld}(29276)
|-php(28092)---sh(12817)---php(12818)
|-portmap(2208)
|-screen(32465)---bash(1102)
|-screen(7952)---bash(7953)---screen(7997)
|-screen(8017)-+-bash(8018)
| `-bash(8093)
|-screen(21321)---bash(21325)
|-screen(31402)---bash(31405)
|-screen(32160)---bash(32161)
|-screen(6035)---bash(6041)
|-screen(11736)---bash(11739)
|-shpchpd_event(1241)
|-ssh(10595)
|-ssh(30680)
|-sshd(2219)-+-sshd(21051)---sshd(21055)---bash(21056)---mysql(21090)
| |-sshd(5440)---sshd(5444)---bash(5445)
| |-sshd(6838)---sshd(6842)---bash(6843)---bash(6895)---ssh(6897)
| |-sshd(23939)---sshd(23943)---bash(23944)
| |-sshd(15181)---sshd(15187)---bash(15188)
| |-sshd(15719)---sshd(15723)---bash(15724)---bash(31820)---ssh(31822)
| `-sshd(13178)---sshd(13182)---bash(13183)---pstree(13625)
|-supervise(2256)---proftpd(2322)
|-supervise.agent(21285)---noah-agent(2035)---noah-agent64(2039)-+-noah-agent64(2040)-+-{noah-agent64}(2098)
| | |-{noah-agent64}(2099)
| | |-{noah-agent64}(2100)
| | |-{noah-agent64}(2101)
| | |-{noah-agent64}(2102)
| | |-{noah-agent64}(2103)
| | |-{noah-agent64}(2104)
| | |-{noah-agent64}(2105)
| | |-{noah-agent64}(2106)
| | |-{noah-agent64}(2107)
| | |-{noah-agent64}(2108)
| | |-{noah-agent64}(2109)
| | |-{noah-agent64}(2110)
| | |-{noah-agent64}(2111)
| | |-{noah-agent64}(2112)
| | |-{noah-agent64}(2113)
| | |-{noah-agent64}(2114)
| | |-{noah-agent64}(2115)
| | |-{noah-agent64}(2116)
| | |-{noah-agent64}(2117)
| | |-{noah-agent64}(2118)
| | |-{noah-agent64}(2119)
| | |-{noah-agent64}(2120)
| | |-{noah-agent64}(2121)
| | |-{noah-agent64}(2122)
| | |-{noah-agent64}(2123)
| | `-{noah-agent64}(2124)
| `-supercpum64(2041)
|-supervise.bscpl(23811)---bscplimitr(23812)
|-supervise.drct(4557)---drct(21674)-+-{drct}(21679)
| |-{drct}(21680)
| |-{drct}(21681)
| |-{drct}(21682)
| |-{drct}(21683)
| |-{drct}(21684)
| |-{drct}(21685)
| |-{drct}(21686)
| |-{drct}(21687)
| |-{drct}(21688)
| |-{drct}(21689)
| |-{drct}(21690)
| |-{drct}(21691)
| |-{drct}(21692)
| |-{drct}(21693)
| |-{drct}(21694)
| |-{drct}(21695)
| |-{drct}(21696)
| |-{drct}(21697)
| |-{drct}(21698)
| |-{drct}(21699)
| |-{drct}(21700)
| |-{drct}(21701)
| |-{drct}(21702)
| |-{drct}(21703)
| |-{drct}(21704)
| `-{drct}(21705)
|-supervise.ocage(21247)---open_vmstat(21251)
|-supervise.ocage(21248)---open_iostat(21252)
|-supervise.ocage(21265)---oc_python(21267)
|-syslogd(3893)
|-tinyproxy(4559)-+-tinyproxy(4567)
| |-tinyproxy(4568)
| |-tinyproxy(4570)
| |-tinyproxy(4572)
| |-tinyproxy(4573)
| |-tinyproxy(4575)
| |-tinyproxy(11283)
| |-tinyproxy(26508)
| |-tinyproxy(6037)
| |-tinyproxy(6038)
| |-tinyproxy(6098)
| |-tinyproxy(22394)
| |-tinyproxy(2605)
| |-tinyproxy(3402)
| |-tinyproxy(10781)
| |-tinyproxy(10824)
| |-tinyproxy(10834)
| |-tinyproxy(11925)
| |-tinyproxy(12358)
| |-tinyproxy(13114)
| |-tinyproxy(12765)
| |-tinyproxy(12778)
| |-tinyproxy(12779)
| |-tinyproxy(12788)
| |-tinyproxy(12789)
| |-tinyproxy(12802)
| |-tinyproxy(12803)
| |-tinyproxy(12812)
| |-tinyproxy(12823)
| |-tinyproxy(12836)
| |-tinyproxy(12837)
| |-tinyproxy(12846)
| |-tinyproxy(12847)
| |-tinyproxy(12860)
| |-tinyproxy(12861)
| |-tinyproxy(12870)
| |-tinyproxy(9971)
| |-tinyproxy(21108)
| |-tinyproxy(17210)
| |-tinyproxy(29420)
| |-tinyproxy(2929)
| |-tinyproxy(583)
| |-tinyproxy(592)
| |-tinyproxy(610)
| |-tinyproxy(619)
| |-tinyproxy(620)
| |-tinyproxy(634)
| |-tinyproxy(643)
| |-tinyproxy(644)
| |-tinyproxy(653)
| |-tinyproxy(658)
| |-tinyproxy(667)
| |-tinyproxy(668)
| |-tinyproxy(677)
| |-tinyproxy(700)
| |-tinyproxy(11924)
| |-tinyproxy(11930)
| |-tinyproxy(11939)
| |-tinyproxy(12212)
| |-tinyproxy(12217)
| |-tinyproxy(12227)
| |-tinyproxy(12236)
| |-tinyproxy(12241)
| |-tinyproxy(12260)
| |-tinyproxy(12281)
| |-tinyproxy(15618)
| |-tinyproxy(2575)
| |-tinyproxy(8055)
| |-tinyproxy(26794)
| |-tinyproxy(889)
| |-tinyproxy(12675)
| |-tinyproxy(12676)
| |-tinyproxy(12685)
| |-tinyproxy(12686)
| |-tinyproxy(12699)
| |-tinyproxy(12700)
| |-tinyproxy(12709)
| |-tinyproxy(12710)
| `-tinyproxy(12741)
|-udevd(1281)
|-vim(16605)
|-vim(16766)
|-vmstat(6129)
`-xinetd(1070)