linux学习命令总结⑩

xiaozhuaia

　　#重定向
　　输出重定向：
　　1>覆盖输出(1可省略)
[root@VM_168_102_centos tmp]# ls functions >shuchu
[root@VM_168_102_centos tmp]# cat shuchu
functions
[root@VM_168_102_centos tmp]# ls fstab >shuchu
[root@VM_168_102_centos tmp]# cat shuchu
fstab　　1>>追加输出(1可省略)
[root@VM_168_102_centos tmp]# cat shuchu
fstab
[root@VM_168_102_centos tmp]# ls functions >>shuchu
[root@VM_168_102_centos tmp]# cat shuchu
fstab
functions　　错误重定向:
　　2>：覆盖输出
[root@VM_168_102_centos tmp]# ls
agent_cmd.sock  fstab      hellodirxyz  scripttest  test
ceshi           functions  rc.sysinit   shuchu
[root@VM_168_102_centos tmp]# ls fstab wanghan >shuchu
ls: cannot access wanghan: No such file or directory
[root@VM_168_102_centos tmp]# cat shuchu
fstab
[root@VM_168_102_centos tmp]# ls fstab wanghan 2>shuchu
fstab
[root@VM_168_102_centos tmp]# cat shuchu
ls: cannot access wanghan: No such file or directory　　2>>：追加输出
[root@VM_168_102_centos tmp]# cat shuchu               
ls: cannot access wanghan: No such file or directory
[root@VM_168_102_centos tmp]# ls ssssdd wanghan 2>>shuchu
[root@VM_168_102_centos tmp]# cat shuchu
ls: cannot access wanghan: No such file or directory
ls: cannot access ssssdd: No such file or directory
ls: cannot access wanghan: No such file or directory　　同时重定标准输出和错误输出：
[root@VM_168_102_centos tmp]# ls fstab wanghan >shuchu 2>cuowu[root@VM_168_102_centos tmp]# cat shuchu
fstab
[root@VM_168_102_centos tmp]# cat cuowu
ls: cannot access wanghan: No such file or directory[root@VM_168_102_centos tmp]# ls fstab wanghan &>all      
[root@VM_168_102_centos tmp]# cat all
ls: cannot access wanghan: No such file or directory
fstab[root@VM_168_102_centos tmp]# ls fstab wanghan >both 2>&1[root@VM_168_102_centos tmp]# cat both
ls: cannot access wanghan: No such file or directory
fstab