摘要：
| command | short for | description | | | | | | cat | concatenate | 从第一行开始显示文件内容 | | tac | inverse of cat | 从最后一行开始显示文件内容 | | nl | number of lines | 输 阅读全文
摘要：
| command | short for | description | | | | | |ls| list files|列出文件名和目录 |cd| change directory| 切换目录 |pwd| print work directory|当前工作目录 |mkdir|make direc 阅读全文