Shell User restrictions

Shell users restrict applications-general Linux technology-Linux programming and kernel information. The following is a detailed description. For example, benny is restricted to use only FTP and e-mail services, but not 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.