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c.IsSet returns true for empty env vars #517
Description
I want to be able to differentiate between empty env vars and unset env vars, but they are treated the same right now:
package main
import (
"fmt"
"os"
"github.com/urfave/cli"
)
func main() {
app := cli.NewApp()
app.Name = "boom"
app.Usage = "make an explosive entrance"
app.Flags = []cli.Flag{
cli.StringFlag{
Name: "thing",
EnvVar: "THING",
},
}
app.Action = func(c *cli.Context) error {
fmt.Printf("isset: %t\n", c.IsSet("thing"))
return nil
}
os.Setenv("THING", "")
//os.Setenv("THING", "set")
app.Run(os.Args)
}
This prints
isset: false
If you uncomment the commented out line it prints:
isset: true
I need both cases to be treated as set. Right now I have some ugly workarounds to do this.
Activity
[-]isset returns true for empty env vars[/-][+]c.IsSet returns true for empty env vars[/+]jszwedko commentedon Sep 3, 2016
Hi @vikstrous,
Thank you for bringing this up. I've gone back and forth on how to treat empty env vars, but I think I agree with you that they should be treated as set and override any defaults defined on the flag. I could see applications depending on this behavior, but given that
IsSetonly actually worked with env vars (#502) as of this past month (and hasn't been officially released), I'm OK with modifying it.