Now that you’re able to navigate the filesystem and inspect files and directories, you’re ready to make alterations to your file system with the following commands:
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cp- copy files and directories -
mv- move or rename files and directories -
rm- remove files and directories -
mkdir- make directories -
rmdir
By the end of this module, you’ll be able to answer the following questions:
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What advantages does the command line serve over a GUI when making changes to the file system?
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Wildcards
Some of the tasks performed by these commands are more easily done with a graphical file manager.
For example: you can drag and drop a file from one directory to another, cut and paste files, delete files, etc.
Simple tasks are good with GUI but complicated good with CL.
cp program copies files and directories
simplest form it copies a single file, type
$ cp file1 file2|
Note
|
… means that an iem can be repeated |
can also copy multiple files (and/or cirectories) to a different directory:
| Command | Result |
|---|---|
cp file1 file2 |
Copies the contents of file1 into file2. If file2 does not exist, it is created; otherwise, file2 is silently overwritten with the contents of file1. |
cp -i file1 file2 |
Like above however, since the "-i" (interactive) option is specified, if file2 exists, the user is prompted before it is overwritten with the contents of file1. |
cp file1 dir1 |
Copy the contents of file1 (into a file named file1) inside of directory dir1. |
cp -R dir1 dir2 |
Copy the contents of the directory dir1. If directory dir2 does not exist, it is created. Otherwise, it creates a directory named dir1 within directory dir2. |
$ cp file... directorycopy all HTML files from one diretory to another, but only copy files that did not exist in the destination directory
$ cp - u *.html destinationShell feature that makes commands so powerful. Saves times by eaily specifying groups of filenames. Wildcards allow you to select filenames based on patterns of characters.
you can use wildcards with any command that sccepts filename arguments.
| Wildcard | Meaning |
|---|---|
* |
Matches any characters |
? |
Matches any single character |
[characters] |
Matches any character that is a member of the set characters. The set of characters may also be expressed as POSIX character class such as one of the following: [:alnum:] Alphanumeric characters [:alpha:] Alphanumeric characters [:digit:] Numerals [:upper:] Uppercase alphabetic characters [:lower:] Lowercase alphabetic characters |
[!characters] |
Matches any character that is not a member of the set characters |
With wildcards, it’s possible to construct very sophisticated selection criteria for filenames. Here are some examples of patterns and what they match
| Pattern | Matches |
|---|---|
* |
All filenames |
g* |
All filenames that begin with the character "g" |
b*.txt |
All filenames that begin with the character "b" and end with the characters ".txt" |
Data??? |
Any filename that begins with the characters "Data" followed by exactly 3 more characters |
[abc]* |
Any filename that begins with "a" or "b" or "c" followed by any other characters |
Any filename that begins with an uppercase letter. This is an example of a character class. |
|
Another example of character classes. This pattern matches any filename that begins with the characters "BACKUP." followed by exactly two numerals. |
|
*[![:lower:]] |
Any filename that does not end with a lowercase letter. |
mv moves or renames files and directories depending on how it’s used
either: a) moves one or more files to a different directory
$ mv filename1 filename2b) will rename a file or directory
$ mv file... directory| command | result |
|---|---|
mv file1 file2 |
If file2 does not exist, then file1 is renamed file2. If file2 exists, its contents are silently replaced with the contents of file1. |
mv -i file1 file2 |
Like above however, since the "-i" (interactive) option is specified, if file2 exists, the user is prompted before it is overwritten with the contents of file1. |
mv file1 file2 file3 dir1 |
The files file1, file2, file3 are moved to directory dir1. If dir1 does not exist, mv will exit with an error. |
mv dir1 dir2 |
If dir2 does not exist, then dir1 is renamed dir2. If dir2 exists, the directory dir1 is moved within directory dir2. |
rm removes (deletes) files and directories
$ rm file ...it can also delete directories
$ rm -r directory...| Command | Results |
|---|---|
rm file1 file2 |
Delete file1 and file2. Delete file1 and file2. |
rm -i file1 file2 |
Like above however, since the "-i" (interactive) option is specified, the user is prompted before each file is deleted. |
rm -r dir1 dir2 |
Directories dir1 and dir2 are deleted along with all of their contents. |
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Warning
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Can’t undelete something after using can cause damage,especially with wildcawrd |
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Tip
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When Using rm with wildcards, construct your command using ls instead. By doing this, you can see the effect of your wildcards before you delete files. |
The mkdir command is used to create directories. Type:
$ mkdir directoryCommand |
Results |
cp *.txt text_files |
Copy all files in the current working directory with names ending with the characters ".txt" to an existing directory named text_files. |
mv my_dir ../*.bak my_new_dir |
Move the subdirectory my_dir and all the files ending in ".bak" in the current working directory’s parent directory to an existing directory named my_new_dir. |
rm *~ |
Delete all files in the current working directory that end with the character "~". Some applications create backup files using this naming scheme. Using this command will clean them out of a directory. |
$ cp mydir mydir1 cp: mydir is a directory (not copied).
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rm: mydir/ is a directory
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rmdir: mydir: Directory not empty