/usr/bin/newgrp
功用：可以改變login的group
語法：newgrp [ group ]

DESCRIPTION

Newgrp有點像是login,他會改變呼叫者的GID只不過原先login的user 仍然在,而你登入的目錄也跟之前相同,但access permissions to file 會換成你所指定的新 group ID.
如果未指定group的話,GID就會換成login的GID

Shared library

libcrypt.so.1 => /lib/libcrypt.so.1 (0x40019000)
libpam.so.0 => /lib/libpam.so.0 (0x40047000)
libdl.so.2 => /lib/libdl.so.2 (0x4004f000)
libpam_misc.so.0 => /lib/libpam_misc.so.0 (0x40053000) libc.so.6 => /lib/libc.so.6 (0x40057000)
/lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x40000000)