LinuxQuestions.org - [SOLVED] why is /usr/sbin not in root's path?

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- - why is /usr/sbin not in root's path? (https://www.linuxquestions.org/questions/debian-26/why-is-usr-sbin-not-in-roots-path-4175736161/)

why is /usr/sbin not in root's path?

I've been using debian bullseye for a while now and noticed that /usr/sbin is not by default in root's path, contrary to other distros. This leads some (third-party) scripts to fail, for instance because they cannot find ldconfig. What, if any, would be the reason debian ommits /usr/sbin from root's path?

Code:

$ whoami

root

$ echo $PATH

/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games

$

I used to use the following at windows (CYGWIN bash.exe)
~/.bashrc file:

Code:

$ /usr/bin/gawk.exe '{ if( ( 8 <= NR ) && ( 11 >= NR ) )  { print $0 } }'  ~/.bash_profile

if [[ -f ~/.bashrc ]]]

then

        . ~/.bashrc

fi

Few contents inside ~/.bashrc file:

Code:

if [[ -d /usr/sbin ]]

then

        echo "$PATH" | /usr/bin/grep -E "^/usr/sbin:|:/usr/sbin:|:/usr/sbin$" 2>&1 |\

        /usr/bin/grep -E -v "^$" >/dev/null 2>&1

        Ret=$?

        if [[ 0 -ne $Ret ]]

        then

                export PATH="/usr/sbin:$PATH"

        fi

fi

if [[ -d /usr/bin ]]

then

        echo "$PATH" | /usr/bin/grep -E "^/usr/bin:|:/usr/bin:|:/usr/bin$" 2>&1 |\

        /usr/bin/grep -E -v "^$" >/dev/null 2>&1

        Ret=$?

        if [[ 0 -ne $Ret ]]

        then

                export PATH="/usr/bin:$PATH"

        fi

fi

if [[ -d /bin ]]

then

        echo "$PATH" | /usr/bin/grep -E "^/bin:|:/bin:|:/bin$" 2>&1 |\

        /usr/bin/grep -E -v "^$" >/dev/null 2>&1

        Ret=$?

        if [[ 0 -ne $Ret ]]

        then

                export PATH="/bin:$PATH"

        fi

fi

if [[ -d /sbin ]]

then

        echo "$PATH" | /usr/bin/grep -E "^/sbin:|:/sbin:|:/sbin$" 2>&1 |\

        /usr/bin/grep -E -v "^$" >/dev/null 2>&1

        Ret=$?

        if [[ 0 -ne $Ret ]]

        then

                export PATH="/sbin:$PATH"

        fi

fi

I agree that we can similar kind of changes inside /etc/bash.bashrc using root(Windows Admin) user.

I am guessing you are using su to login as root. su still uses the user's path environment but su - switches to root's environment. debian does not add /usr/sbin to the user's path while others do.

Yes, if you are switching to root using su then you will need the -l option to start with an environment similar to a real root login.

Indeed, I was using su without flags, thanks for clarifying.
- debian does have /usr/sbin in root's path (but not in a user's path)
- su without -l preserves that user's environment

Quote:

Originally Posted by cmk77 (Post 6496800)

What, if any, would be the reason debian ommits /usr/sbin from root's path?

Absolutely no idea, but it's just annoying. There are certain commands in /sbin you may want to run as a normal user (such as ifconfig).

In Debian, my method is to set the $PATH variable early in ~/.profile as follows:

Code:

# ~/.profile: executed by the command interpreter for login shells.

# This file is not read by bash(1), if ~/.bash_profile or ~/.bash_login

# exists.

# see /usr/share/doc/bash/examples/startup-files for examples.

# the files are located in the bash-doc package.



# the default umask is set in /etc/profile; for setting the umask

# for ssh logins, install and configure the libpam-umask package.

#umask 022

export PATH=$PATH:/usr/local/sbin:/usr/sbin:/sbin

[...]

Log out and back in.

Even when the path is set as above, you should still su to root as follows in order to use root's environment:

Code:

$ su -l

The reason that certain utilities and system programs aren't directly in the root or super users' path is because the /sbin folder is a symbolic link back to the user sbin folder.

~/.bashrc or ~/.mkshrc or ~/.kshrc for all users including root

Quote:

Originally Posted by cmk77 (Post 6496858)

Indeed, I was using su without flags, thanks for clarifying.
- debian does have /usr/sbin in root's path (but not in a user's path)
- su without -l preserves that user's environment

if I am facing this issue:
I should have added following code inside ~/.bashrc or ~/.kshrc or ~/.mkshrc based on different OS
for all users including root user

Code:

OS=$(/usr/bin/uname -s 2>&1 | /usr/bin/sed "s/-[0-9]*\.[0-9]*\-[0-9]*//;")

case $OS in

        "Linux")

                if [[ -f /usr/bin/grep ]]

                then

                        EGREP="/usr/bin/grep -E"

                elif [[ -f /usr/bin/egrep ]]

                then

                        EGREP="/usr/bin/egrep"

                fi

                ;;

        "SunOS")

                if [[ -f /usr/bin/grep ]]

                then

                        EGREP="/usr/bin/grep -E"

                elif [[ -f /usr/bin/egrep ]]

                then

                        EGREP="/usr/bin/egrep"

                fi

                ;;

        "AIX")

                if [[ -f /usr/bin/grep ]]

                then

                        EGREP="/usr/bin/grep -E"

                elif [[ -f /usr/bin/egrep ]]

                then

                        EGREP="/usr/bin/egrep"

                fi

                ;;

        "HP-UX")

                if [[ -f /usr/bin/grep ]]

                then

                        EGREP="/usr/bin/grep -E"

                elif [[ -f /usr/bin/egrep ]]

                then

                        EGREP="/usr/bin/egrep"

                fi

                ;;

        "CYGWIN_NT")

                if [[ -f /usr/bin/grep ]]

                then

                        EGREP="/usr/bin/grep -E"

                elif [[ -f /usr/bin/egrep ]]

                then

                        EGREP="/usr/bin/egrep"

                fi

                ;;

        *)

                #echo use related path to grep

                if [[ -f /usr/bin/grep ]]

                then

                        EGREP="/usr/bin/grep -E"

                elif [[ -f /usr/bin/egrep ]]

                then

                        EGREP="/usr/bin/egrep"

                fi

                ;;

esac

if [[ -d /usr/sbin ]]

then

        echo $PATH 2>&1 |\

        $EGREP "^/usr/sbin:|:/usr/sbin:|:/usr/sbin$" >/dev/null 2>&1

        Ret=$?

        if [[ 0 -ne $Ret ]]

        then

                export PATH="/usr/sbin:$PATH"

        else #DEBUG01

                echo "\$PATH having /usr/sbin" #DEBUG02

        fi

else #DEBUG03

        /usr/bin/ls -ltrd /usr/sbin #DEBUG04

fi

The user's path isn't what changed, "/usr/sbin" has always been in the root path only.
What did change is the behavior of su.

Quote:

The su command in buster is provided by the util-linux source package, instead of the shadow source package, and no longer alters the PATH variable by default. This means that after doing su, your PATH may not contain directories like /sbin, and many system administration commands will fail. There are several workarounds:

Use su - instead; this launches a login shell, which forces PATH to be changed, but also changes everything else including the working directory.

Use sudo instead. sudo still runs commands with an altered PATH variable.

To get a regular root shell with the correct PATH, you may use sudo -s.

To get a login shell as root (equivalent to su -), you may use sudo -i.

Put ALWAYS_SET_PATH yes in /etc/default/su (create it) to get an approximation of the old behavior. This is documented in su(1).

Put the system administration directories (/sbin, /usr/sbin, /usr/local/sbin) in your regular account's PATH (see EnvironmentVariables for help with this).

https://wiki.debian.org/NewInBuster

Thanks jens, that really explains it