将/etc/issue文件中的内容转换为大写后保存至/tmp/issue.out文件中
[root@CentOS7 ~]#tr '[:lower:]' [:upper:] < /etc/issue >/tmp/issue.out
[root@CentOS7 ~]#cat /tmp/issue.out
\S
KERNEL \R ON AN \M
将/etc/issue文件中的内容转换为大写后保存至/tmp/issue.out文件中
[root@CentOS7 ~]#tr '[:lower:]' [:upper:] < /etc/issue >/tmp/issue.out
[root@CentOS7 ~]#cat /tmp/issue.out
\S
KERNEL \R ON AN \M