diff options
author | Thomas Voss <mail@thomasvoss.com> | 2021-10-08 23:54:38 +0200 |
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committer | Thomas Voss <mail@thomasvoss.com> | 2021-10-08 23:54:38 +0200 |
commit | 2f1422138e8c6ef9cd18bf28ec1cfa8868e53ba8 (patch) | |
tree | b02a1651f9ab5fbce933f004fcf165e923704277 /README.rst | |
parent | e59861fc928c2b6e715f2c586dc6e22ab49ebcd2 (diff) |
[Format] Update README code examples
The code examples now use tabs instead of spaces, because who the hell
unironically uses spaces. Also the later examples now have syntax
highlighting because smoothbrain Thomas didn't think of that earlier.
Diffstat (limited to 'README.rst')
-rw-r--r-- | README.rst | 98 |
1 files changed, 52 insertions, 46 deletions
@@ -1,4 +1,4 @@ -.. vi: tw=100 +.. vi: tw=100 noet Getgopt ======= @@ -19,40 +19,40 @@ There is only 1 function for you to use, and that is ``getgopt.Getopt()``. The f .. code-block:: go - package main - - import ( - "fmt" - "os" - - "github.com/Mango0x45/getgopt" - ) - - func main() { - for opt := byte(0); getgopt.Getopt(len(os.Args), os.Args, ":a:bcd", &opt); { - switch opt { - case 'a': - fmt.Printf("Parsed the -a flag with the argument '%s'\n", - getgopt.Optarg) - case 'b': - fmt.Println("Parsed the -b flag") - case 'c': - /* ... */ - case 'd': - /* ... */ - case '?': - fmt.Fprintf(os.Stderr, "Invalid flag '%c', read the manpage\n", - getgopt.Optopt) - os.Exit(1) - case ':': - fmt.Fprintf(os.Stderr, "The flag '%c' requires an argument\n", - getgopt.Optopt) - os.Exit(1) - } - } - - fmt.Printf("The first non-option argument is '%s'\n", os.Args[getgopt.Optind]) - } + package main + + import ( + "fmt" + "os" + + "github.com/Mango0x45/getgopt" + ) + + func main() { + for opt := byte(0); getgopt.Getopt(len(os.Args), os.Args, ":a:bcd", &opt); { + switch opt { + case 'a': + fmt.Printf("Parsed the -a flag with the argument '%s'\n", + getgopt.Optarg) + case 'b': + fmt.Println("Parsed the -b flag") + case 'c': + /* ... */ + case 'd': + /* ... */ + case '?': + fmt.Fprintf(os.Stderr, "Invalid flag '%c', read the manpage\n", + getgopt.Optopt) + os.Exit(1) + case ':': + fmt.Fprintf(os.Stderr, "The flag '%c' requires an argument\n", + getgopt.Optopt) + os.Exit(1) + } + } + + fmt.Printf("The first non-option argument is '%s'\n", os.Args[getgopt.Optind]) + } After parsing a flag the ``Getopt()`` function returns true if there are still more flags to parse, or false if there are none more. This means that we can use it in a ``for`` or ``while`` loop to @@ -68,27 +68,33 @@ is ``':'`` and otherwise it will be ``'?'``. The *optstring* is a string passed as the 3rd argument to ``Getopt()`` which specified which flags you want to be able to handle. Each flag you want to handle is given as a single character in the string in any order. For example if you want to support the ``-a``, ``-b``, and ``-x`` flags you can -do:: +do: - getgopt.Getopt(len(os.Args), os.Args, "abx", &opt) - /* or */ - getgopt.Getopt(len(os.Args), os.Args, "bxa", &opt) +.. code-block:: go + + getgopt.Getopt(len(os.Args), os.Args, "abx", &opt) + /* or */ + getgopt.Getopt(len(os.Args), os.Args, "bxa", &opt) If you want a flag to take an argument, you should suffix the character with a ``':'``. So using the -above example, if we want the ``-b`` flag to take an argument, we could write:: +above example, if we want the ``-b`` flag to take an argument, we could write: + +.. code-block:: go - getgopt.Getopt(len(os.Args), os.Args, "ab:x", &opt) + getgopt.Getopt(len(os.Args), os.Args, "ab:x", &opt) Finally, by default the ``Getopt()`` function will print diagnostic error messages to standard output when the user fails to provide an argument to a flag that expects one or passes an invalid flag. If you would like to not have these diagnostics printed you can either prefix the optstring with ``':'`` or you can set the ``Opterr`` global variable to ``false``. Both of the following are -equivalent:: +equivalent: + +.. code-block:: go - getgopt.Getopt(len(os.Args), os.Args, ":ab:x", &opt) - /* or */ - getgopt.Opterr = false - getgopt.Getopt(len(os.Args), os.Args, "ab:x", &opt) + getgopt.Getopt(len(os.Args), os.Args, ":ab:x", &opt) + /* or */ + getgopt.Opterr = false + getgopt.Getopt(len(os.Args), os.Args, "ab:x", &opt) There is a *slight* difference in behavior though which was explained above. |