Login shell dev null
This is supposed to help the user understand what happened, though in practice many terminal emulators will simply close when the shell terminates, rendering the message all but unreadable anyway cisco 3500 switch manual in some cases.
If not, add it by hand.
Sudo chsh -s /usr/bin/vim mike99.0) no matter the return of /some/program.Setting the shell to /bin/true has the same effect of not allowing someone to log in but false is probably used as a convention over true since it's much better at conveying the concept that person doesn't have a shell.You can always redirect both standard error (stdin) and standard out (stdout) text to an output file or a log file by typing the following command: command file 2 1 /path/to/my/cool/appname myapp.Syntax to redirect error and output messages to /dev/null.Scponly can be used as a shell in this instance.In either case, scp will not operate with an invalid shell.
You can send output to /dev/null, by using command /dev/null syntax.
However, this will not work when command will use the standard error (FD # 2).
How do I redirect the output of stderr to stdout, and then redirect this combined output to /dev/null device?What is the importance of using 2 1?Consider setting the hash in /etc/shadow the same way to avoid bugs.Passwd -l will do this for you.sbin/nologin is a BSD utility which has similar behaviour to /bin/false (returns boolean false but prints output as well, as /bin/false is prohibited from doing.Posix (though I may be wrong and it may the the SUS) constrains both these commands to do exactly nothing other than return the appropriate boolean value.The syntax discussed below works with Bourne-like shells, such as sh, ksh, and bash: command /dev/null./ /dev/null./ /dev/null 2 1 command /dev/null./ /dev/null./ /dev/null.Source wikipedia, part 3: 2 1 file descriptor, whenever you executes a program by default operating system open three files stdin, stdout, and stderr as we know whenever a file is opened the system returns a small integer called as file descriptor.bin/false is just a binary that immediately exits, returning false, when it's called, so when someone who has false as shell logs in, they're immediately logged out when false exits.