Summary

• Options modify the behavior of commands:

• • ls -a lists all contents of a directory, including hidden files and directories
• ls -l lists all contents in long format
• ls -t orders files and directories by the time they were last modified
• Multiple options can be used together, like ls -alt
• From the command line, you can also copy, move, and remove files and directories:
• cp copies files
• mv moves and renames files
• rm removes files
• rm -r removes directories
• Wildcards are useful for selecting groups of files and directories

Manipulation

Learn how to copy, move, and delete files and directories from the command line

$ ls -a

. .. .preferences action drama comedy genres.xt

• The lscommand lists all files and directories in the working directory.

• ls -ato display the contents of the working directory in more detail , 其實就是列出所有內容，包含隱藏的檔案

• The-amodifies the behavior of the lscommand to also list the files and directories starting with a dot (.). Files started with a dot are hidden, and don't appear when using lsalone.

• 把檔名開頭是 .的檔案列出來

• -a並不一定要加

List Command and Options

• ls -a 的 -a 叫做 option

• Options modify the behavior of commands

• -a

• lists all contents, including hidden files and directories

• -l

• lists all contents of a directory in long format,可以看到資料夾下有什麼檔案

• long format 請見補充說明的文章 The Wide and Long Data Format

• 呈現像 table，下個這個例子有 4 rows, 7 column，每一個欄位代表

• Access rights. These are actions that are permitted on a file or directory.

• Number of hard links.This number counts the number of child directories and files. This number includes the parent directory link (..) and current directory link (.).

• The username of the file's owner. Here the username is cc.

• The name of the group that owns the file. Here the group name is eng

• The size of the file in bytes.

• The date & time that the file was last modified.

• The name of the file or directory.

• $ ls -l
  drwxr-xr-x 5 cc eng 4096 Jun 24 16:51 action
  drwxr-xr-x 4 cc eng 4096 Jun 24 16:51 comedy
  drwxr-xr-x 6 cc eng 4096 Jun 24 16:51 drama
  -rw-r--r-- 1 cc eng 0 Jun 24 16:51 genres.txt
  

• ls -alt

• 是 ls-a 和 ls -l 和 ls-t 的綜合體

• lists all contents, including hidden files and directories, in long format, ordered by the date and time they were last modified.

• $ ls -alt
  drwxr-xr-x 4 cc eng 4096 Jun 29 12:22 .
  -rw-r--r-- 1 cc eng 0 Jun 29 12:22 .gitignore
  drwxr-xr-x 5 cc eng 4096 Jun 30 14:20 ..
  drwxr-xr-x 2 cc eng 4096 Jun 29 12:22 satire
  drwxr-xr-x 2 cc eng 4096 Jun 29 12:22 slapstick
  -rw-r--r-- 1 cc eng 14 Jun 29 12:22 the-office.txt
  

• -t

• Order files and directories by the time they were last modified.

Cp Command

cp biopic/cleopatra.txt historical/

• 複製檔案某個資料夾的檔案，到某個資料夾

• 第一個 argument 是 biopic/cleopatra.txt，第二個 是 historical/

cp biopic/ray.txt biopic/notorious.txt historical/

• 也可以一次複製兩個檔案
• first arguments 是 biopic/ray.txt 和 biopic/notorious.txt，第二個是 historical/

Wildcards

cp * satire/

• 除了用檔案名當 arguments 外，我們可以使用 special character 像 *
• *用來 select groups of files，這個特殊符號我們叫 Wildcards
• The*selects all files in the working directory, so here we use cpto copy all files into the satire/ directory.

cp m*.txt scifi/

• m*.txtselects all files in the working directory starting with "m" and ending with ".txt", and copies them to scifi/

Mv Command

• 移動檔案，使用方式類似 cp

mv superman.txt superhero/

• 把 first argument 移到 second argument

mv wonderwoman.txt batman.txt superhero/

• 把 前二個 arguments 移到 second argument

mv batman.txt spiderman.txt

• 這一項很特別，這是改名!!!
• By moving batman.txt into spiderman.txt, we rename the file as spiderman.txt

Rm Command

rm waterboy.txt

• 用來刪除檔案或資料夾

rm -r comedy

• The-ris an option that modifies the behavior of thermcommand.
• The-rstands for "recursive," and it's used to delete a directory and all of its child directories.
• 把整個資料夾都刪除，要注意這是永久刪除!!

rm media/*

練習題