Mandatory options with getopt_long() in C

Question

With C/ C++, getopt_long() can be used to parse command line arguments. Is it possible to tell the function that some of the options are mandatory? For example, how can I tell getopt_long that the parsing should give error if startServer is called without mentioning the port below?

./startServer -port 80

Note: I am not talking of option arguments as mandatory but rather the options themselves.

i doubt there's a way. keep track of whether that option has been seen? — lijie, Jan 12 '11 at 12:46

score 5 · Accepted Answer · answered Jan 12 '11 at 15:00

getopt_long() is not part of the C language. It is a GNU invention which is available in some C implementations, but far from all.

The version of getopt_long() in glibc (used in most Linux distributions) does not allow you to specify that an option is mandatory. You'll have to check them explicitly after you're done parsing the command line.

Mandatory options with getopt_long() in C

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