Why "-bash: ifconfig : command not found" when typing "$ifconfig"
 

i typed "$ifconfig" in the redhat 4. And it returned above error.other users, it does not matter at all. So someone can tell me the reason.


thanks!

Run as root, the command is "ifconfig"

Any reason else?

Because ifconfig is locate in /sbin
sbin is not in the path from regular users, only in path from root.
you can execute the command by typing /sbin/ifconfig

Well, this happens only if you have a variable ifconfig whose value is ifconfig and you're not root, that is
but I see no reason to launch a command as $variable, unless you have a script which dynamically set the name of the command and store it in a shell variable. Moreover, as already stated by SqdnGuns above, you have to be root to run ifconfig otherwise - as a regular user - it is not in your PATH.

Actually, you can run the ifconfig command as a regular user if you launch it with its absolute path:
but only to display the ethernet interface settings, not to modify the settings themselves - for which you have to acquire root privileges. Please note that in my examples above the greyed $ sign is the command prompt.

Thank everybody
 

I understood more about this issue!

thanks!

sudo export PATH=/sbin:$PATH

no need for sudo
in fact, it won't work, since export is a bash builtin command

add this line in ~/bashrc file
export PATH=$PATH:/sbin

~/.bashrc

but better to have it in ~/.profile
that way it is also available to other shells ( ksh, ash , csh and so on )