Command line prompter for terminal user interaction with the following features:
- input prompt scans into any variable type (
string,bool,int,time.Time, ..., or custom types) - input is editable in-place
- select prompt with options
- enter and yes/no prompt
- input validation
See also github.com/tdewolff/argp for a command line argument parser.
TODO: capture terminal resize event TODO: handle long labels for prompt/select
Make sure you have Git and Go (1.13 or higher) installed, run
mkdir Project
cd Project
go mod init
go get -u github.com/tdewolff/prompt
Then add the following import
import (
"github.com/tdewolff/prompt"
)A regular prompt requesting user input. When the target is a primary type (except boolean) or implements the Stringer interface, it will be editable in-place.
package main
import "github.com/tdewolff/prompt"
func main() {
// Validators verify the user input to match conditions.
validators := []prompt.Validator{prompt.StrLength(5, 10), prompt.Suffix("suffix")}
var val string
deflt := prompt.Default("value", 3) // set text caret to the 3rd character
if err := prompt.Prompt(&val, "Label", deflt, validators...); err != nil {
panic(err)
}
fmt.Println("Result:", val)
}where val can be of any primary type, such as string, []byte, bool, int, int8, int16, int32, int64, uint, uint8, uint16, uint32, uint64, float32, float64, or time.Time.
When the value is editable it allowd users to use keys such as: Left, Ctrl + B to move left; Right, Ctrl + F to move right; Home, Ctrl + A to go to start; End, Ctrl + E to go to end; Backspace and Delete to delete a character; Ctrl + K and Ctrl + U to delete from the caret to the start and end of the input respectively; Enter, Ctrl + D to confirm input; and Ctrl + C, Esc to quit.
A list selection prompt that allows the user to select amongst predetermined options.
package main
import "github.com/tdewolff/prompt"
func main() {
val, deflt := "", "Yellow" // can be ints if you need the index into options
options := []string{"Red", "Orange", "Green", "Yellow", "Blue", "Purple"}
if err := prompt.Select(&val, "Label", options, deflt); err != nil {
panic(err)
}
fmt.Println("Selected:", val)
}The select prompt allows users to use keys such as: Up, Shift + Tab to go up; Down, Tab to go down; Enter, Ctrl + D to select option; Ctrl + C to quit; and Esc to cancel the selection.
When there are many options, it is possible to enter a query to filter options.
A yes or no prompt returning true or false.
package main
import "github.com/tdewolff/prompt"
func main() {
deflt := false
if prompt.YesNo("Label", deflt) {
fmt.Println("Yes")
} else {
fmt.Println("No")
}
}true is any of 1, y, yes, t, true and is case-insensitive.
false is any of 0, n, no, f, false and is case-insensitive.
A prompt that waits for Enter to be pressed.
package main
import "github.com/tdewolff/prompt"
func main() {
prompt.Enter("Are you done?") // waits for enter
}Not(Validator) // logical NOT
And(Validator...) // logical AND
Or(Validator...) // logical OR
Is(any) // is exact match
In([]any) // in list
NotIn([]any) // not in list
StrLength(min, max int) // limit string length (inclusive)
NumRange(min, max float64) // limit int/uint/float range (inclusive)
DateRange(min, max time.Time) // limit time.Time range (inclusive)
Prefix(afix string)
Suffix(afix string)
Pattern(pattern, message string) // pattern match and error message
EmailAddress()
IPAddress() // valid IPv4 or IPv6 address
IPv4Address()
IPv6Address()
Port() // server port
Path() // Unix path
AbsolutePath() // Unix absolute path
UserName() // valid Unix user name
TopDomainName() // such as example.com
DomainName() // such as sub.example.com
FQDN() // such as sub.example.com.
Dir() // existing directory
File() // existing fileReleased under the MIT license.