Wildcards

CS155 Wildcards

Vocabulary
Punctuation	`*`, `?`, `[]`, `{}`
Grammar

Wildcards

Often, we wish to apply a command to multiple files or directories
Wildcards can help us do this efficiently
The wildcard symbols are: *, ?, [], {}
- * – match zero or more characters
- ? – match any one character
- [] – match any characters in the brackets
- {} – match any word in the brackets

Wildcards: Examples 1

Select all files ending in .txt

% cd ~/pub
% ls
area-codes   dwarfs.txt  greek	   hw2Files  index.php	planets
domains.txt  Examples	 hw1Files  hw3.tgz   numbers
% ls *.txt
domains.txt  dwarfs.txt

All files beginning with d

% cd ~/pub
% ls d*
domains.txt  dwarfs.txt

Wildcards: Examples 2

Any file with an n in its name:

% cd ~/pub
% ls *n*
domains.txt  index.php	numbers  planets

Files beginning with hw,followed by a digit, ending with an s

% cd ~/pub
% ls -d hw[0-9]*s
hw1Files  hw2Files

Text and PHP files. Note the comma!

% cd ~/pub
% ls -d *.{php,txt}
domains.txt  dwarfs.txt  index.php

Wildcards: In Use

Move all .txt files into the directory files

    % mv *.txt files

Remove all files beginning with HW, followed by a digit, and ending with .file

    % rm HW[0-9].file

List all files ending with .txt or .jpg

    % ls -l *.{txt,jpg} | more

Example Failure

Student: “I tried your examples, and none of them work!”
That’s because these examples are executing as user cs155, not as you. Therefore, ~ in the examples refers to ~cs155, cs155’s home directory.
To get them to work, use ~cs155 instead of ~.
Of course, the other form, ~username, doesn’t have to be changed.

CS155: Introduction to Unix

Spring 2018

Wildcards

Wildcards

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Wildcards

Wildcards: Examples 1

Wildcards: Examples 2

Wildcards: In Use

Example Failure