miscutils

func DupeByteSlice ¶

func DupeByteSlice(in []byte) (out []byte)

DupeByteSlice allocates and returns a duplicate of the input byte slice. As with many things in Go, there is more than one way to skin a cat.

func GetKeypress ¶

func GetKeypress() byte

GetKeypress reads and returns (as a `byte`) a keypress.

func InteractiveInput ¶

func InteractiveInput(prompt string) string

InteractiveInput displays the argument string as a prompt and then reads and returns a string entered by the user (ended by `Enter`).

func Into ¶

func Into(s string) time.Time

Into starts a timer and (if the string argument is non-empty) writes to `os.Stderr`; the timer is ended by passing it to `Outa(..)`, which can be placed in a `defer` statement. Note that the caller must store the start time, but that this means we can have nested timers.

These functions add a dependency on package `time`, but it is also possible to rewrite them to use `interface{}`.

func IsBitSet ¶

func IsBitSet(flagset, index byte) bool

IsBitSet returns the numbered bit. Bit 0 is rightmost. It may or may not work for more than 16 bits in flagset. .

func IsNil ¶

func IsNil(x interface{}) bool

IsNil checks whether an interface value is nil, and to do this correctly, it checks BOTH values.

func It ¶

func It() *singleton

It returns the single instance. Come to think of it tho, this looks like lazy instantiation; maybe it belongs in a `func init()` ?

func Must ¶

func Must[T any](val T, err error) T

Must enforces error-free func calls: a panic is triggered by a non-nil error returned by any func of the form: MyFunc(..) (someValue, error)

func Outa ¶

func Outa(s string, t time.Time)

Outa stops a clock that was started by `Into(..)`, and also writes the elapsed time (in a human-friendly format) to `os.Stderr`. The message is less informative if the string starts with `!` (which is not printed).

func PressAnyKey ¶

func PressAnyKey()

PressAnyKey issues a message to the user and then waits until,,, any key is pressed. The key is not echoed back to the user and is not returned to the caller.

func RTEnv ¶

func RTEnv() string

RTEnv tries to identify the runtime environment. It uses lots of stuff from package os:

• Probably useful:
• Environ() []string
• Getenv(key string) string // LookupEnv distinguishes btwn empty and unset
• Getwd() (dir string, err error)
• UserHomeDir() (string, error)
• UserConfigDir() (string, error)
• Hostname() (name string, err error)
• Probably not useful:
• Executable() (string, error)
• UserCacheDir() (string, error)
• Getegid() int
• Geteuid() int
• Getgid() int
• Getuid() int

func RunCommand ¶

func RunCommand(cmdname string, args ...string) (stdout string, stderr string, err error)

RunCommand runs `cmdname` with the supplied 0-or-more arguments. It waits for the command to finish, and then it returns the command's `Stdout` and `Stderr`, plus any error that prevented execution.

Pass the command and its arguments as a list of individual tokens, rather than as a single string with blanks as separators. .

func SanitizeInput ¶

func SanitizeInput(input string) string

SanitizeInput applies the following rules: - trim all extra white space - trim all carriage return characters - trim leading / ending quotation marks (ex.: "my text") - trim leading / ending spaces

func Tri ¶

func Tri[T any](cond bool, a, b T) T

Tri implements the ternary operator.

func Uuidv7 ¶

func Uuidv7() ([16]byte, error)

Uuidv7 is a cut & paste from somewhere or 'nother.