Where does the bash PATH on CentOS 7 get /usr/local/bin from?

Question

I've just spun up a brand new CentOS 7 VM (bash version 4.2.46) with Vagrant using the centos/7 box, and when I'm logged in as the vagrant user, this is my PATH:

/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/home/vagrant/.local/bin:/home/vagrant/bin

When logged in as root, here's the PATH:

/usr/local/sbin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

I know that /etc/profile is adding /usr/local/sbin:/usr/sbin (at the end for most users, at the start for root), and the /etc/skel/.bash_profile that ends up in the vagrant home directory is adding /home/vagrant/.local/bin:/home/vagrant/bin, but where is the initial setting coming from?

At present I have no explanation of why users end up with /usr/local/bin:/usr/bin in their PATH, and root gets the others.

(Frankly, the ordering of the root PATH seems very odd, given that /usr/local/sbin and /usr/sbin should be at the end, according to /etc/profile.)

Answer 1

In the bash source "config-top.h" has this:

/* The default value of the PATH variable. */
#ifndef DEFAULT_PATH_VALUE
#define DEFAULT_PATH_VALUE \
  "/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin:."
#endif

/* The value for PATH when invoking `command -p'.  This is only used when
   the Posix.2 confstr () function, or CS_PATH define are not present. */
#ifndef STANDARD_UTILS_PATH
#define STANDARD_UTILS_PATH \
  "/bin:/usr/bin:/sbin:/usr/sbin:/etc:/usr/etc"
#endif

Answer 2

Other people have asked the same thing on the CentOS bug tracker. The earliest post I found was this one.

/usr/local/bin is hardcoded in /bin/bash.

1. https://bugs.centos.org/view.php?id=10200
2. https://bugs.centos.org/view.php?id=10199
3. https://bugs.centos.org/view.php?id=10198
4. https://bugs.centos.org/view.php?id=7492

As you will see this problem was first reported in May 2012, and has existed in CentOS 6 and CentOS 7.

So as confusing as it may be, it looks like your analysis the paths are not coming from /etc/profile is correct. The paths are coming from /bin/bash.

Answer 3

It definitely looks hard coded into /bin/bash

strings /bin/bash | grep "\/usr\/local\/bin"
/usr/local/bin:/bin:/usr/bin

which seems to be the default PATH.

Answer 4

In addition to previous answers; If you are reaching you VM by ssh this could has sense.

In /etc/ssh/sshd_config:

# This sshd was compiled with PATH=/usr/local/bin:/usr/bin

Answer 5

I came across this today (in my case it wasn't present in the PATH) and I realized this only happens in login shells. If you run a shell as another user /usr/local/bin won't get added to the path (For example su <username>). Maybe that's what happens with vagrant