How to restrict applications by Shell users

Article Title: How to restrict applications by Shell users. Linux is a technology channel of the IT lab in China. Including desktop applications, Linux system management, kernel research, embedded systems, open source, and other basic classification examples: Restrict benny users to use only FTP and e-mail services, instead of using telnet or ssh

[Root @ localhost] # vi/etc/passwd

Radvd: x: 75: 75: radvd user: // sbin/nologin

Amanda: x: 33: 6: Amanda user:/var/lib/amanda:/bin/bash

Pegasus: x: 66: 65: tog-pegasus OpenPegasus WBEM/CIM services:/var/lib/Pegasus:/sbin/nologin

Jimmy: x: 501: 501:/home/jimmy:/bin/bash

Benny: x: 502: 502:/home/benny:/bin/false // after modification, change the original/bin/bash to/bin/false.

Lambert: x: 503: 503:/home/lambert:/bin/bash

[Root @ localhost] # vi/etc/shells

/Bin/sh

/Bin/bash

/Sbin/nologin

/Bin/ash

/Bin/bsh

/Bin/ksh

/Usr/bin/ksh

/Usr/bin/pdksh

/Bin/tcsh

/Bin/csh

/Bin/zsh

/Bin/false // This row is newly added

Note: falsh or null must be specified for this user. If only the shell is deleted without adding any files, the system will automatically enable the shell preset by sh when logging on to the user.