open
<programming >
1. To prepare to read or write a file. This usually involves checking whether the file already exists and that the user has the necessary authorisation to read or write it. The result of a successful open is usually some kind of capability (e.g. a Unix file descriptor) - a token that the user passes back to the system in order to access the file without further checks and finally to close the file.
<character >
2. Abbreviation for "open (or left) parenthesis" - used when necessary to eliminate oral ambiguity. To read aloud the LISP form (DEFUN FOO (X) (PLUS X 1)) one might say: "Open defun foo, open eks close, open, plus eks one, close close."
<software >
3. Non-proprietary. An open standard is one which can be used without payment.
<mathematics >
4. open interval.
Nearby terms:
Opal ♦ OPC ♦ op code ♦ open ♦ open box testing ♦ open brace ♦ OpenBSD ♦ open/closed principle
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