 preface.txt outline.txt
[tony@free tony]$ cat preface.txt >> outline.txt
 new.txt info.txt readme.txt
[tony@free tony]$ cat new.txt info.txt >readme.txt
9, mv
mv move
[tony@free backup]$ mv a.txt .. a.txt
[tony@free backup]$ mv z1.txt z3.txt z1.txt z3.txt
[tony@free backup]$ cd..
[tony@free tony]$ mv backup.. backup
10 pwd
pwd(print working directory)
[tony@free tony]$ pwd
/home/tony /home/tony
11, locate
locate
[tony@free tony]$ locate zh_CN zh_CN
locate
root updatedb
12 grep
grep
[tony@free etc]$ grep text *.conf .conf text