Why Bash unable to find command even if $PATH is specified properly?

Question

I am specifying path to my command in the file /etc/profile:

export PATH=$PATH:/usr/app/cpn/bin

My command is located in:

$ which ydisplay 
/usr/app/cpn/bin/ydisplay

So, when I performing "echo $PATH" output is looks like:

$ echo $PATH
...:/usr/app/cpn/bin

And everything is OK, but when I am trying to launch my command via SSH I am getting error:

$ ssh 127.0.0.1 ydisplay
$ bash: ydisplay: command not found

But the my path is still present:

$ ssh 127.0.0.1 echo $PATH
...:/usr/app/cpn/bin

Please explain me why Bash unable to find ydisplay during SSH session and how to properly configurate SSH to avoid this issue.

More over, if I specifying $PATH in local file .bashrc in the current user all works correctly. But I want to modify only one file instead specifying a lot of files for each user. This is why I am asking.

Answer 1

tl;博士

运行ssh 127.0.0.1 ydisplay源~/.bashrc而不是/etc/profile. ~/.bashrc改为更改您的路径。

细节

唯一/etc/profile读取的时间是您的 shell 是“登录 shell”。

来自Bash 参考手册：

当 bash 作为登录 shell 被调用时，...它首先从文件 /etc/profile 读取并执行命令

但是当你运行ssh 127.0.0.1 ydisplay,bash不是作为登录 shell 启动的。但它确实读取了不同的启动文件。该猛砸参考手册说：

当 ... 由 ... sshd 执行时。...它读取并执行来自~/.bashrc

所以你应该把你的PATH设置放在~/.bashrc.

在大多数系统上，~/.bash_profilesource ~/.bashrc，因此您可以仅将设置放入~/.bashrc而不是将它们放入两个文件中。

有更改设置为所有用户没有标准的方法，但大多数系统都有一个/etc/bashrc，/etc/bash.bashrc或类似的。

如果失败，请设置pam_env并将PATH设置放入/etc/environment.

也可以看看：

• 登录和非登录shell之间读取的conf文件是什么？
• 是否有所有 shell 读取的“.bashrc”等效文件？