I have been trying to check the alias the all the user can possible have on my system, I am using root.  There is any command that can list them?
How to list all the alias for all the user have on my linux box from root
shell;alias
That's not really possible because aliases only exist when the user is logged in.  If their .profile etc login scripts define some aliases, they will have those when they first log in, but they may also source other scripts to define more aliases or define them on the command-line.You can, however, list the aliases that each user will have at the moment they log in with something like this:#! /bin/bashfor user in $(getent passwd | cut -d: -f1) ; do    uid=$(getent passwd $user | cut -d: -f3)    if [ $uid -ge 1000 ] ; then        ushell=$(getent passwd $user | cut -d: -f7)        [ -z $ushell ] && ushell='/bin/sh'        echo aliases for $user:        if [[ $ushell =~ /s?bin/(true|false|sync|ftponly|nologin) ]] ; then            :        elif [[ $ushell =~ /s?bin/(t?csh|zsh|s?ash) ]] ; then            su - $user $ushell -c 'alias'        elif [[ $ushell =~ /s?bin/([bd]ash|m?ksh|sh) ]] ; then             su - $user $ushell -c 'alias -p'        fi        echo ; echo    fidoneNote that this skips all UIDs below 1000 - on debian systems, normal (i.e. non-system) user ids start at 1000.  On some other systems, they start at 500.  adjust to suit your system.It's possible that some shells may not list aliases when told to execute alias without an argument.  All the shells I tested (bash, dash, pdksh, mksh, tcsh, zsh) were OK with it but if you find one that doesn't you'll have to handle that with something like if [ $ushell = /bin/oddshell ; then ... fi