为什么‘`ps’比‘`ps’显示更多的过程？

Question

来自ps手册页：

默认情况下，ps作为当前用户选择具有相同有效用户ID (euid=EUID)的所有进程，并与调用方相关联。

在我的Ubuntu系统上，没有任何标志的ps提供了如下输出，如预期的那样：

$ ps
  PID TTY          TIME CMD
 6444 pts/11   00:00:00 bash
14605 pts/11   00:00:00 ps

现在，再次从输出修饰符中的ps手册页面：

e      Show the environment after the command.

但是，当我尝试ps e时，我得到了更多的进程列表：

$ ps e
  PID TTY      STAT   TIME COMMAND
   85 pts/1    Ss+    0:00 -bash HOSTTYPE=x86_64 LANG=C.UTF-8 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:
  100 pts/2    Ss+    0:00 -bash HOSTTYPE=x86_64 LANG=C.UTF-8 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:
  115 pts/3    Ss+    0:00 -bash HOSTTYPE=x86_64 LANG=C.UTF-8 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:
  130 pts/4    Ss+    0:00 -bash HOSTTYPE=x86_64 LANG=C.UTF-8 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:
  146 pts/5    Ss+    0:00 -bash HOSTTYPE=x86_64 LANG=C.UTF-8 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:
  174 pts/6    Ss+    0:00 -bash HOSTTYPE=x86_64 LANG=C.UTF-8 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:
 2988 pts/9    Ss     0:01 -bash HOSTTYPE=x86_64 LANG=C.UTF-8 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:
 3477 pts/9    S+     0:00 vi stepniak.json SHELL=/bin/bash WSL_DISTRO_NAME=Ubuntu-20.04 WT_SESSION=55c420c4-12cf-4f4c-b957-b0b42e2777b8 JAVA_HOME=/home/myr
 4513 pts/0    Ss+    0:02 -bash HOSTTYPE=x86_64 LANG=C.UTF-8 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:
 4540 pts/7    Ss+    0:00 -bash HOSTTYPE=x86_64 LANG=C.UTF-8 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:
 5653 pts/10   Ss+    0:01 -bash HOSTTYPE=x86_64 LANG=C.UTF-8 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:
 6444 pts/11   Ss     0:00 -bash HOSTTYPE=x86_64 LANG=C.UTF-8 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:
 7942 pts/12   Ss     0:00 -bash HOSTTYPE=x86_64 LANG=C.UTF-8 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:
17962 pts/12   Sl     0:03 /home/myroot/jdk-11.0.2/bin/java -classpath /mnt/c/k8s-developer/maven-3.6.3/boot/plexus-classworlds-2.6.0.jar -Dclassworlds.conf
17997 pts/11   R+     0:00 ps e SHELL=/bin/bash WSL_DISTRO_NAME=Ubuntu-20.04 WT_SESSION=7e85f66b-c77a-42da-8782-c0912c196b46 JAVA_HOME=/home/myroot/jdk-11.0
24958 pts/12   Sl     1:05 java -jar myapp.jar SHELL=/bin/bash WSL_DISTRO_NAME=Ubuntu-20.04 WT_SESSION=d9a61855-27fe-4757-a7c9-a38f38fe7fc7 JAVA
25185 pts/12   S+     0:03 tail -f nohup.out SHELL=/bin/bash WSL_DISTRO_NAME=Ubuntu-20.04 WT_SESSION=d9a61855-27fe-4757-a7c9-a38f38fe7fc7 JAVA_HOME=/home/my

据我所知，e是一个输出修饰符，它不应该更改用于选择流程的标准(这通常是用-e、a等完成的)。

So为什么 ps e listing比ps**更多？**

注： ps -f或ps -F按预期工作-

$ ps -F
UID        PID  PPID  C    SZ   RSS PSR STIME TTY          TIME CMD
myroot    6444  6443  0  4333 12404   2 00:25 pts/11   00:00:00 -bash
myroot   19976  6444  0  2655  3340   7 23:05 pts/11   00:00:00 ps -F

我的操作系统信息：

$ cat /etc/*rel*
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=20.04
DISTRIB_CODENAME=focal
DISTRIB_DESCRIPTION="Ubuntu 20.04.3 LTS"
NAME="Ubuntu"
VERSION="20.04.3 LTS (Focal Fossa)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 20.04.3 LTS"
VERSION_ID="20.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=focal
UBUNTU_CODENAME=focal

Answer 1

ps e使用BSD样式选项(遵循procps名称)，还有这个。

还将更改进程选择，以包括您拥有的其他终端(TTY)上的进程。

e选项本身不会更改所选内容，但它会更改为默认选择包括当前和其他终端上的所有进程的模式。

其他BSD风格的输出控制选项具有相同的效果；例如，请参见ps l或ps u。