Linux有许多内置命令,内置命令type可以用来判断一个命令是否为内置命令。
type: usage: type [-afptP] name [name ...]
[root@vm-centos tor]# type ulimit ulimit is a shell builtin [root@vm-centos tor]# type tor tor is /usr/local/bin/tor [root@vm-centos tor]# type -t tor file [root@vm-centos tor]# type -t ulimit builtin [root@vm-centos tor]# type -a ls ls is aliased to `ls --color=auto' ls is /bin/ls [root@vm-centos tor]# type ls ls is aliased to `ls --color=auto' [root@vm-centos tor]#