According to the documentation for getopt, you are supposed to include unistd.h. However, I've recently discovered that this doesn't work on all systems. Using getopt.h instead of unistd.h appears to fix the …

To parse command-line long options in C, use getopt_long() with argc and argv. If 0, no optarg. If 1, requires an optarg. If 2, optional optarg.

GNU getopt() behaves like standard getopt(); it returns options in the order in which they are found, stopping at the first nonoption argument. This will also be true if POSIXLY_CORRECT exists in the …

Getopt There’s a better way! getopt() and getopt_long() The latter enables longer options (e.g., “--help”) Useful (and mostly standard now), but we won’t use it in this course Basic idea: callgetopt() …

There is also new package introduced in 2012 which contains all the features of argparse both getopt and optparse but which has a dependency on Python 2.7 or 3.2+. Some Features unlikely to be …

Global variables are set by getopt: optarg–A pointer to the current option argument. optind–An index of the next argv pointer to process when getopt is called again. Long options with *getopt_long(…) …

getopt() Conventions use getopt() in a loop to iterate through each command-line option and terminate loop once the function returns -1 use switch(c) to dispatch on the return value from getopt() , where …