It took to analyze the user on the machine running CentOs, search engines give usually the physical location of records such as / etc / passwd .... it is certainly good, but still need to see the editor (who need to know the options), I will discuss the getent team that It is able to display the console information on different databases list of which is available on the team
getent --h
The parameter that interests us and passwd command looks like this
getent passwd
You get a full list of users who registered in the file / etc / passwd. There is also another list or shadow (hidden / etc / shadow) his team
getent gshadow
Do not forget that you can just copy the list to a file for further analysis, the command looks like this
getent passwd > /the way to saving the file
Here, enjoy.