POSIX-compliant

[joseluisq]

Cline must be POSIX-compliant according to https://www.gnu.org/software/libc/manual/html_node/Argument-Syntax.html

• Arguments are options if they begin with a hyphen delimiter (‘-’).
• Option names are single alphanumeric characters.
• Certain options require an argument. For example, the ‘-o’ command of the ld command requires an argument—an output file name.
• Options typically precede other non-option arguments.
• The argument ‘--’ terminates all options; any following arguments are treated as non-option arguments, even if they begin with a hyphen.
• A token consisting of a single hyphen character is interpreted as an ordinary non-option argument. By convention, it is used to specify input from or output to the standard input and output streams.
• An option and its argument may or may not appear as separate tokens. (In other words, the whitespace separating them is optional.) Thus, ‘-o foo’ and ‘-ofoo’ are equivalent.
• Multiple options may follow a hyphen delimiter in a single token if the options do not take arguments. Thus, ‘-abc’ is equivalent to ‘-a -b -c’.
• Options may be supplied in any order, or appear multiple times. The interpretation is left up to the particular application program.
• Long options consist of ‘--’ followed by a name made of alphanumeric characters and dashes. Option names are typically one to three words long, with hyphens to separate words. Users can abbreviate the option names as long as the abbreviations are unique.
• To specify an argument for a long option, write ‘--name=value’. This syntax enables a long option to accept an argument that is itself optional.