![]() ![]() ![]() To ensure continued operation of historical applications: Separate argument from its option-argument and that option-arguments not be optional, but there are some exceptions in POSIX.1-2017 The Utility Syntax Guidelines in Utility Syntax Guidelines require that the option be a Option-argument (if present) is included within the same argument string as the option for a mandatory option-argument, it is the This reflects the situation in which an optional In the '' notation to indicate that it is optional. Option-arguments are shown separated from their options by characters, except when the option-argument is enclosed The arguments following the last options and option-arguments are named "operands". Certain options are followed by an "option-argument", as shown with. TheĪrguments that consist of characters and single letters or digits, such as 'a', are known as It is followed by options, option-arguments, and operands. The utility in the example is named utility_name. Simple reference for the application developer or system user. The notation used for the SYNOPSIS sections imposes requirements on the implementors of the standard utilities and provides a Utility descriptions use this notation, which is illustrated by this example (see XCU Simple Commands): utility_name Within POSIX.1-2017, a special notation is used for describing the syntax of a utility's arguments. This section describes the argument syntax of the standard utilities and introduces terminology used throughout POSIX.1-2017 forÄescribing the arguments processed by the utilities. Utility Conventions 12.1 Utility Argument Syntax The - convention is followed by the vast majority of Unix command line utilities and is a standard feature of most argument parsing libraries written for most languages.The Open Group Base Specifications Isedition If you do ls - *, ls interprets the option - as meaning it should cease trying to process options and treat all the rest of the arguments as files or directories it should give a listing for. in front of it, so ls won't interpret any of the arguments as options. * instead of * the shell will do a glob expansion that results in everything having. if you didn't provide an argument is a simple default, not any kind of special behavior. If you then do ls * there, the shell will give all those directories as arguments, and ls will give you a listing for each of them. One other interesting demonstration here is to make a directory that has a bunch of directories in it. This isn't how it works on Windows, which I think is a major flaw in how Windows handles command line programs. And so it parses them for flags like it would any other command line arguments. ls has no clue if you typed those arguments, or if they are the result of a glob expansion. The shell then passes the results as a bunch of command line arguments to ls. The thing that does the globbing is the shell. and lists out that directory like it would any directory you gave it on the command line. If you don't give it any arguments, it assumes you meant. I think the important missing conceptual leap here is where the globbing is done. ![]()
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