Wildcards

In a command line, in order to write many file names that have a common property, wildcards can be used. There is a huge set of wildcards which are used to specify regular expression. These will be learned by heavy usage of the system. We will show the most frequently used wildcards.

• ? stands for one character. For example if you want to list all the files that start with fin and has one additional character in the name, give the following command: ls -l fin*
  .

  <mendelson:~/ceng111> ls -l
  -rw-r--r--   1 selcuk          0 Oct  6 11:14 fin
  -rw-r--r--   1 selcuk          0 Oct  6 11:14 fina
  -rw-r--r--   1 selcuk          0 Oct  6 11:14 final
  -rw-r--r--   1 selcuk          0 Oct  6 11:14 finb
  -rw-r--r--   1 selcuk          0 Oct  6 11:14 grab
  <mendelson:~/ceng111> ls -l fin?
  -rw-r--r--   1 selcuk          0 Oct  6 11:14 fina
  -rw-r--r--   1 selcuk          0 Oct  6 11:14 finb
  

  Note that only the files that start with fin and has one more letter are displayed.
  
• * Stands for zero or more letters. In the above example to list all files that start with fin, give the following command: ls -l fin*
  .

  <mendelson:~/ceng111> ls -l fin*
  -rw-r--r--   1 selcuk          0 Oct  6 11:14 fin
  -rw-r--r--   1 selcuk          0 Oct  6 11:14 fina
  -rw-r--r--   1 selcuk          0 Oct  6 11:14 final
  -rw-r--r--   1 selcuk          0 Oct  6 11:14 finb
  

  The wildcards are expanded by the shell, not the command itself. This means that the ls command we gave in the following command is executed after the wildcards are expanded. The resulting command and arguments passed to ls is as follows: ls -l fin fina final finb .