1、把/etc/fstab文件内容重定向到/tmp目录下文件名为fstab.out
[root@centos8 ~]#cat /etc/fstab > /tmp/fstab.out
2、把hello world追加到/tmp/fstab.out文件尾部
[root@centos8 ~]#echo "hello world" >> /tmp/fstab.out
3、禁止覆盖重定向和强制重定向
[root@centos8 ~]#set -C [root@centos8 ~]#echo a > /tmp/fstab.out -bash: /tmp/fstab.out: cannot overwrite existing file [root@centos8 ~]#echo a >| /tmp/fstab.out [root@centos8 ~]#cat /tmp/fstab.out a
4、某文件权限为:drw-r--r--,用数值形式表示该权限,则该八进制为?
答:644
5、显示/etc/inittab中以#开头,且后面跟着一个或多个空白字符,而后又跟了任意非空白字符的行?
[root@centos8 ~]#grep -E "^#[[:space:]]+[^[:space:]]*" /etc/inittab # inittab is no longer used. # ADDING CONFIGURATION HERE WILL HAVE NO EFFECT ON YOUR SYSTEM. # Ctrl-Alt-Delete is handled by /usr/lib/systemd/system/ctrl-alt-del.target # systemd uses 'targets' instead of runlevels. By default, there are two main targets: # multi-user.target: analogous to runlevel 3 # graphical.target: analogous to runlevel 5 # To view current default target, run: # systemctl get-default # To set a default target, run: # systemctl set-default TARGET.target
6、建立一个新文件可使用的命令
答:touch FILENAME
> FILENAME
cat /dev/null > FILENAME
cat > FILENAME < FILENAME
7、用vim,给文件test.sh的132到186行一次性添加#注释?
答::132,186s/^/^#/
8、如何看file1文件的第300-500行的内容
答:head -n500 file1 | tail -n200 file1
9、可以一次显示一页内容的命令是是吗?
答:less more