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。

[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 contextsPID    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

选项	功能
-a --arguments	显示进程对应命令行有参数，如果是被记忆体置换出去的进程则会加上括号
-A --ascii	使用ASCII码线条绘制字符
-c --compact	如果有重复的进程名, 则分开列出（预设值是会在前面加上 *）
-h --highlight-all	突出显示当前流程及其祖先
-H PID --highlight-pid=PID	突出显示指定PID的过程及其祖先
-g --show-pgids	显示进程组 ID;隐含 -c
-G --vt100	使用 VT100 线条绘制字符
-l --long	不要截断长线
-n --numeric-sort	按 PID 对输出进行排序
-N type --ns-sort=type	按命名空间类型排序（IPC、MNT、NET、PID、USER、UTS）
-p --show-pids	显示 PID;隐含 -c
-s --show-parents	显示所选进程的父进程
-S --ns-changes	显示命名空间转换
-u --uid-changes	显示 UID 转换
-U --unicode	使用 UTF-8 （Unicode） 线条绘制字符
-V --version	显示版本信息

1.3 pstree命令的参数

参数	说明
PID	从指定的PID开始，默认值为1
USER	以指定用户显示进程树

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

[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

[purpleendurer @ bash ~] pstree -p 795
accounts-daemon(795)─┬─{gdbus}(834)└─{gmain}(824)
[purpleendurer @ bash ~]