例如xen中的xm命令.

键入xm [space] [tab]并打印出有效选项
哪个是：

addlabel        destroy         info            network-attach  resume          sysrq           vnet-delete
block-attach    dmesg           labels          network-detach  rmlabel         top             vnet-list
block-detach    domid           list            network-list    save            trigger         vtpm-list
block-list      domname         loadpolicy      new             sched-credit    unpause         
cfgbootpolicy   dry-run         log             pause           sched-sedf      uptime          
console         dump-core       makepolicy      reboot          serve           vcpu-list       
create          dumppolicy      mem-max         rename          shutdown        vcpu-pin        
debug-keys      getlabel        mem-set         resources       start           vcpu-set        
delete          help            migrate         restore         suspend         vnet-create

那太漂亮了！

如何在Linux中实现自己的tab命令完成？