Wildcards

[dos2unix]

Using Wildcards in Linux Filenames​

What is a Wildcard?​

A wildcard is a symbol used in file management commands to represent one or more characters. They allow you to perform operations on multiple files that match a certain pattern without specifying each file individually. The most common wildcards are:

• * (asterisk): Represents zero or more characters.
• ? (question mark): Represents exactly one character.
• [] (square brackets): Represents any one of the enclosed characters.

Example Commands​

1. Copy (cp)
   • Copy all .txt files:

     cp *.txt /destination/directory/

     
     
   • Copy files starting with Jan:

     cp Jan* /destination/directory/

2. Move (mv)
   • Move all .jpg files:

     mv *.jpg /destination/directory/

     
     
   • Move files ending with 01.mp3:

     mv *01.mp3 /destination/directory/

3. Remove (rm)
   • Remove all .log files:

     rm *.log

     
     
   • Remove files starting with Feb:

     rm Feb*

4. List (ls)
   • List all .png files:

     ls *.png

     
     
   • List files ending with 02.txt:

     ls *02.txt

Wildcard Examples​

1. Wildcard at the Beginning
   • Copy files ending with .doc:

     cp *.doc /destination/directory/

2. Wildcard at the End
   • Move files starting with Report:

     mv Report* /destination/directory/

3. Double Wildcards
   • Remove files containing data in the middle:

     rm *data*

Specific Example: Copying Files with Specific Patterns​

Imagine you have a directory with hundreds of files, most of which begin with a three-letter month abbreviation (e.g., Jan, Feb, Mar) and have various suffixes like .jpg, .mp3, .txt, etc. For example:

• JanChicago01.mp3
• SepAtlanta06.doc
• FebAtlanta02.txt
• MayBoston05.jpg
• OctBoston07.png

To copy all files that contain Boston in the middle to another directory, you can use double wildcards:

cp *Boston* /destination/directory/

Advantages of Command Line Over GUI​

While GUI file managers allow sorting files by name, date, and type, they often lack the flexibility to sort and manage files based on complex patterns involving multiple criteria. Command-line tools, with the help of wildcards, provide powerful and efficient ways to handle such tasks, making them invaluable for managing large sets of files with specific naming conventions.

 

[dos2unix]

Using ? Wildcard​

The ? wildcard represents exactly one character. Here are some examples:

1. Copy (cp)
   • Copy files with names like file1.txt, file2.txt, etc.:

     cp file?.txt /destination/directory/

2. Move (mv)
   • Move files with names like a1.jpg, b2.jpg, etc.:

     mv ?.jpg /destination/directory/

3. Remove (rm)
   • Remove files with names like log1, log2, etc.:

     rm log?

4. List (ls)
   • List files with names like data1.csv, data2.csv, etc.:

     ls data?.csv

Using [] Wildcard​

The [] wildcard allows you to specify a set of characters. Here are some examples:

1. Copy (cp)
   • Copy files with names like file1.txt, file2.txt, file3.txt:

     cp file[123].txt /destination/directory/

2. Move (mv)
   • Move files with names like a.jpg, b.jpg, c.jpg:

     mv [abc].jpg /destination/directory/

3. Remove (rm)
   • Remove files with names like log1, log2, log3:

     rm log[123]

4. List (ls)
   • List files with names like dataA.csv, dataB.csv, dataC.csv:

     ls data[A-C].csv

Combining Wildcards​

You can also combine these wildcards for more complex patterns:

1. Copy (cp)
   • Copy files with names like fileA1.txt, fileB2.txt, etc.:

     cp file[A-Z]?.txt /destination/directory/

2. Move (mv)
   • Move files with names like a1.jpg, b2.jpg, c3.jpg:

     mv [a-c]?.jpg /destination/directory/

3. Remove (rm)
   • Remove files with names like logA1, logB2, logC3:

     rm log[A-C]?[1-3]

4. List (ls)
   • List files with names like dataA1.csv, dataB2.csv, dataC3.csv:

     ls data[A-C]?[1-3].csv

These examples should help you understand how to use the ? and [] wildcards effectively.

 

[Alexzee]

Using ? Wildcard​

The ? wildcard represents exactly one character. Here are some examples:

1. Copy (cp)
   • Copy files with names like file1.txt, file2.txt, etc.:

     cp file?.txt /destination/directory/

2. Move (mv)
   • Move files with names like a1.jpg, b2.jpg, etc.:

     mv ?.jpg /destination/directory/

3. Remove (rm)
   • Remove files with names like log1, log2, etc.:

     rm log?

4. List (ls)
   • List files with names like data1.csv, data2.csv, etc.:

     ls data?.csv

Using [] Wildcard​

The [] wildcard allows you to specify a set of characters. Here are some examples:

1. Copy (cp)
   • Copy files with names like file1.txt, file2.txt, file3.txt:

     cp file[123].txt /destination/directory/

2. Move (mv)
   • Move files with names like a.jpg, b.jpg, c.jpg:

     mv [abc].jpg /destination/directory/

3. Remove (rm)
   • Remove files with names like log1, log2, log3:

     rm log[123]

4. List (ls)
   • List files with names like dataA.csv, dataB.csv, dataC.csv:

     ls data[A-C].csv

Combining Wildcards​

You can also combine these wildcards for more complex patterns:

1. Copy (cp)
   • Copy files with names like fileA1.txt, fileB2.txt, etc.:

     cp file[A-Z]?.txt /destination/directory/

2. Move (mv)
   • Move files with names like a1.jpg, b2.jpg, c3.jpg:

     mv [a-c]?.jpg /destination/directory/

3. Remove (rm)
   • Remove files with names like logA1, logB2, logC3:

     rm log[A-C]?[1-3]

4. List (ls)
   • List files with names like dataA1.csv, dataB2.csv, dataC3.csv:

     ls data[A-C]?[1-3].csv

These examples should help you understand how to use the ? and [] wildcards effectively.

Very helpful dos2unix.

I've never used wildcards before. so now I can thanks for the write up with examples.