Chapter 16
Wildcard Matching
16.1 Do This
> ls *.txt
Directory: C:\Users\zed\temp
Mode LastWriteTime Length Name
---- ------------- ------ ----
-a--- 12/22/2011 5:23 PM 38 another.txt
-a--- 12/22/2011 5:23 PM 38 ex15.txt
> ls ex*.*
Directory: C:\Users\zed\temp
Mode LastWriteTime Length Name
---- ------------- ------ ----
-a--- 12/22/2011 5:23 PM 38 ex15.txt
> ls e*
Directory: C:\Users\zed\temp
Mode LastWriteTime Length Name
---- ------------- ------ ----
-a--- 12/22/2011 5:23 PM 38 ex15.txt
> ls *t
Directory: C:\Users\zed\temp
Mode LastWriteTime Length Name
---- ------------- ------ ----
-a--- 12/22/2011 5:23 PM 38 another.txt
-a--- 12/22/2011 5:23 PM 38 ex15.txt
> cat *.txt
I am a new file.
I am a new file.
> rm *.txt
> ls
>
16.2 You Learned This
Sometimes you want to do a command to a set of files all at once. The way you do this is to use the * (asterisk) symbol to say "anything." Wherever you put the asterisk, the shell will build a list of all the files that match the non-asterisk part.
In this exercise you list out various files that you've made so far. I have a few extra that were hanging out in my directory, and you might have others. The key is that, by writing *.txt, you are saying "anything ending in .txt".
At the end we use rm *.txt to remove all of the .txt files in the temp directory.
16.3 Do More
- Add the * to your deck of flash cards. On the back write: "matches anything in a wildcard like *.txt".
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