UNIX for Dummies Questions & Answers

HI i am new to Unix&LInux world my question is
what dose the question mark ins this command mean

Code:

find . –type d –name “?d*” –print

i tried to to run it without it did not notice any change.
Thx.

That's a wildcard, not a regular expression ("?" stands for a single character).

Some implementations of "find" support "regex" and "iregex" flags.

Any single character.

See Shell Command Language (and note that find uses pattern matching notation, not regular expressions as such).

In case the previous comments were too cryptic, the command:

Code:

find . –type d –name "?d*" –print

will look for files in or under the current directory (.) of type directory (-type d) with a name that is any single character followed by the letter d followed by zero or more other characters (-name "?d*"and prints the pathnames of any files that match these criteria (-print).

Note that I used "?d*", not “?d*”. Although opening- and closing-double-quote characters may be nicer visually when typing text, plain double-quote characters are required when passing arguments to the shell (unless you're actually looking for files with names containing the opening- and closing-double-quote characters).

Also note that the -print primary is not needed in this find command because it just specifies the default behavior in this case.