Bash: Command Not Found
 

I installed Red Hat Enterprises 5
when I try to issue the commands useradd, usermod, or userdel
it gives me the following error message:

bash: useradd: command not found
bash: usermod: command not found
bash: userdel: command not found

I checked these commands in the following path and I found them
/usr/sbin/useradd
/usr/sbin/usermod
/usr/sbin/userdel

what does that mean ????

pleassssss help meeee

Hi and welcome to LinuxQuestions!

Most likely you are trying these commands as a normal user, whereas they are system commands reserved to the system administrator (that is the Linux super-user, named root). As you can see they are in the /usr/sbin directory, that according to the Filesystem Hierarchy Standard contains commands for which root's privileges are required.

Indeed, if you check your PATH environment variable:
you cannot see /sbin nor /usr/sbin in the (colon separated) list of directories, hence the command not found error. On the contrary, if you gain root's privileges you will see them listed and you'll have these commands at your disposal.

In addition to the official Red Hat documentation, I suggest the more friendly "The Linux Command Line" book, that explains these basic concepts in a plain and clear way.

when im using Level 5 then its works. but in GUI mode (level 7) didn't work....

I don't know what level 5 and level 7 are----it sounds like level 5 might have a root environment (different $PATH)

Check the PATH in both levels---but also try to simply enter "su" in a terminal to switch to root user.

its called RUN Level's.

Alt+Ctrl+F5 or Alt+Ctrl (F1 to F7)

F7 is full GUI mode.

As a normal user, PATH does not include everything /sbin. Also, executables in /sbin are normally only executable by an EUID 0 user or root.

no, that is not run level (I think). Alt+Ctrl+F5 will give you a command window where you can log in as root, Alt+Ctrl F7 will give you a GUI where usually normal users are logged in.
/usr/sbin is available only for root, normal users are not allowed to use those tools (as it was mentioned before)

Indeed, runlevels are not the same as different login screens https://en.wikipedia.org/wiki/Runlev...nux_and_Fedora

The reason of "command not found" is already said in colucix post itself.
run
As a root or super user check whether or not the path is set to environment variables using
If not, then set path variable using
or whereever you find the path from whereis command. And then excecute useradd, userdel, usermod commands as root/super user, or simply use full path whichever you have found from whereis command like
And dont get confuse with runlevels and terminals

Thank u friends... Problem is solved... & once again thanks for help...