0 前言

在

Linux shell编程学习笔记59： ps 获取系统进程信息，类似于Windows系统中的tasklist 命令

https://blog.csdn.net/Purpleendurer/article/details/139696466?spm=1001.2014.3001.5501

中我们研究了ps命令。在Linux中，通过ps命令，我们可以查看系统中运行的进程信息，包括进程的ID、父进程ID、CPU和内存占用等信息。不过ps命令显示的进程信息中，进程间的父子关系还不够直观。

Linux还提供了pstree命令，可以以树的形式直观地显示进程间的关系。

1 pstree 命令 的功能、格式和选项说明

我们先看一下pstree命令的帮助信息。

pstree命令 不支持 --help选项。

<code>[purpleendurer @ bash ~] pstree --help

pstree: 未知的选项 `--help'

Usage: pstree [ -a ] [ -c ] [ -h | -H PID ] [ -l ] [ -n ] [ -p ] [ -g ] [ -u ]

[ -A | -G | -U ] [ PID | USER ]

pstree -V

Display a tree of processes.

-a, --arguments show command line arguments

-A, --ascii use ASCII line drawing characters

-c, --compact don't compact identical subtrees

-h, --highlight-all highlight current process and its ancestors

-H PID,

--highlight-pid=PID highlight this process and its ancestors

-g, --show-pgids show process group ids; implies -c

-G, --vt100 use VT100 line drawing characters

-l, --long don't truncate long lines

-n, --numeric-sort sort output by PID

-N type,

--ns-sort=type sort by namespace type (ipc, mnt, net, pid, user, uts)

-p, --show-pids show PIDs; implies -c

-s, --show-parents show parents of the selected process

-S, --ns-changes show namespace transitions

-u, --uid-changes show uid transitions

-U, --unicode use UTF-8 (Unicode) line drawing characters

-V, --version display version information

-Z show SELinux security contexts

PID start at this PID; default is 1 (init)

USER show only trees rooted at processes of this user

[purpleendurer @ bash ~]

1.1 pstree 命令 的功能

显示进程树（Display a tree of processes）。

1.2  pstree命令的格式

ps [选项]   [PID |  USER]

或

 ps -V

1.3 pstree命令的选项

1.3 pstree命令的参数

2 pstree命令实列

2.1 pstree | more 分页显示进程树

[purpleendurer @ bash ~] pstree | more

systemd-+-ETSMJBZGN0---3*[{ETSMJBZGN0}]

|-ETSMJBZGN10

|-ETSMJBZUI1-+-29*[QOperationLogTh]

| |-11*[QRemoveLabelThr]

| |-{QFunctionPipe}

| |-{QKeepSessionThr}

| |-2*[{QOperationLogTh}]

| |-{QPluginOutPipe}

| |-{QProcessManager}

| |-{QRightMenuPipe}

| `-{QSLPluginPipe}

|-ETSMJBZUI11---8*[{ThreadServer}]

|-ETSMJBZUI13---sleep

|-ETSMJBZWJTX0---{ETSMJBZWJTX0}

|-2*[ETSMJBZWJTX1]

|-FoxitOfficeSuit---FoxitOfficeSuit-+-FoxitUpgrade

| `-3*[{FoxitOfficeSuit}]

|-NetworkManager-+-dhclient

| |-dnsmasq

| |-{gdbus}

| `-{gmain}

|-PNXClientHost.o---PNXClientHost.o

|-SuwellUpdateSer

|-WLHXXYCGN701

|-WLHXXYCGN702---{WLHXXYCGN702}

|-WLHXXYCGN802

|-accounts-daemon-+-{gdbus}

| `-{gmain}

|-acpid

|-activation-daem

|-2*[agetty]

|-aptd---{gmain}

|-auditd---{auditd}

|-avahi-daemon---avahi-daemon

|-backup-daemon---{QDBusConnection}

|-biometric-authe-+-2*[{biometric-authe}]

| |-{gdbus}

| `-{gmain}

|-2*[cat]

--更多--

 2.2 pstree -apn | more ：用ASCII码线条绘制字符显示在运行的进程树，包括命令参数和PID

<code>[purpleendurer @ bash ~] pstree -apn | more

systemd,1 splash

|-sqaxsafeforcnos,367 --minishow

| |-{QXcbEventReader},371

| |-{llvmpipe-0},386

| |-{llvmpipe-1},387

| |-{llvmpipe-2},388

| |-{llvmpipe-3},389

| |-{QDBusConnection},390

| |-{gmain},415

| |-{gdbus},416

| |-{CASocketThread},428

| |-{sqaxsafeforcnos},432

| |-{sqaxsafeforcnos},433

| |-{sqaxsafeforcnos},434

| |-{sqaxsafeforcnos},435

| |-{sqaxsafeforcnos},436

| |-{sqaxsafeforcnos},437

| |-{sqaxsafeforcnos},438

| |-{sqaxsafeforcnos},439

| |-{sqaxsafeforcnos},497

| |-{sqaxsafeforcnos},498

| |-{sqaxsafeforcnos},499

| |-{sqaxsafeforcnos},500

| |-{sqaxsafeforcnos},501

| |-{sqaxsafeforcnos},502

| |-{sqaxsafeforcnos},503

| |-{sqaxsafeforcnos},504

| |-{sqaxsafeforcnos},506

| |-{sqaxsafeforcnos},507

| |-{sqaxsafeforcnos},508

| |-{sqaxsafeforcnos},509

| |-{sqaxsafeforcnos},510

| |-{sqaxsafeforcnos},511

| |-{sqaxsafeforcnos},512

| |-{sqaxsafeforcnos},516

| |-{XTableThread},520

| |-{SpeedCtrl},522

| |-{QThread},524

| `-{CpuMemState},525

|-systemd-udevd,420

|-haveged,423 --Foreground --verbose=1 -w 1024

|-systemd-journal,425

|-qaxtray_5,518 --reboot

| |-{QXcbEventReader},523

| |-{llvmpipe-0},526

| |-{llvmpipe-1},527

| |-{llvmpipe-2},528

| |-{llvmpipe-3},529

| |-{QDBusConnection},530

| |-{gmain},531

| |-{gdbus},532

| |-{qaxtray_5},581

| |-{qaxtray_5},582

| |-{qaxtray_5},583

| |-{qaxtray_5},584

| |-{QThread},591

--更多--

3.3  pstree -p 795：显示以PID为795的进程为根的进程树，包括PID

<code>[purpleendurer @ bash ~] pstree -p 795

accounts-daemon(795)─┬─{gdbus}(834)

└─{gmain}(824)

[purpleendurer @ bash ~]