Pattern Matching in case Statements

A case statement () is good at string pattern matching. Its "wildcard" pattern-matching metacharacters work like the filename wildcards () in the shell, with a few twists. Here are some examples:

• ?)
• Matches a string with exactly one character like a, , !, and so on.
• ?*)
• Matches a string with one or more characters (a non-empty string).
• [yY]|[yY][eE][sS])
• Matches y, Y or yes, YES, YeS, etc. The | means "or."
• /*/*[0-9])
• Matches a file pathname, like /xxx/yyy/somedir/file2, that starts with a slash, contains at least one more slash, and ends with a digit.
• 'What now?')
• Matches the pattern What now?. The quotes () tell the shell to treat the string literally: not to break it at the space and not to treat the ? as a wildcard.
• "$msgs")
• Matches the contents of the msgs variable. The double quotes let the shell substitute the variable's value; the quotes also protext spaces and other special characters from the shell. For example, if msgs contains first next, then this would match the same string, first next.

- JP