Re: [go-nuts] Global variable initialized in init() not working in main()

[Michael Brizic]

Thank you, missed that, didn't fully understand the nature of *defer*, but 
now I do!

On Monday, February 5, 2018 at 3:42:10 PM UTC-6, Thomas Bushnell, BSG wrote:
>
> Your init is closing the file before returning, so at that point all the 
> writes are failing. If you check the error you receive from logger.Print 
> you should see something to that effect.
>
> Thomas
>
>
> On Mon, Feb 5, 2018 at 1:39 PM  wrote:
>
>> I'm initializing a Logger variable in an init() function and then 
>> attempting to use in the main() function. However, I'm able to Printf from 
>> the Logger in the init() function but not inside the main() function. Any 
>> help would be appreciated.
>>
>> package main
>>
>> import (
>>
>> "fmt"
>> "log"
>> "io"
>> 
>> "os"
>>
>> }
>>
>> var (
>>
>> logFile *os.File 
>> logger *log.Logger
>> multiWriter io.Writer
>>
>> )
>>
>> func init() {
>>
>> fmt.Println("init() function")
>>
>> var logFileError error
>> logFile, logFileError = os.Create("gopoc.log")
>> if logFileError != nil {
>> panic(logFileError)
>> }
>> defer logFile.Close()
>>
>> fmt.Println("Creating log file")
>>
>> multiWriter = io.MultiWriter(logFile, os.Stdout)
>>
>> logger = log.New(multiWriter, gopocLogPrefix, log.Ldate | log.Ltime | 
>> log.Lshortfile)
>> logger.SetOutput(multiWriter)
>>
>> fmt.Println("Created logger")
>>
>> logger.Printf("Using logger")  // prints to console and logFile as 
>> expected
>>
>> }
>>
>> func main() {
>>
>> fmt.Println("main() function ") // prints to console
>>
>> fmt.Println(logger) // I can see the object pointer
>>
>> logger.Print("hello") // This does not print to logFile nor 
>> os.Stdout !!!
>>
>> }
>>
>> -- 
>> You received this message because you are subscribed to the Google Groups 
>> "golang-nuts" group.
>> To unsubscribe from this group and stop receiving emails from it, send an 
>> email to golang-nuts...@googlegroups.com .
>> For more options, visit https://groups.google.com/d/optout.
>>
>

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Re: [go-nuts] Global variable initialized in init() not working in main()

['Thomas Bushnell, BSG' via golang-nuts]

Your init is closing the file before returning, so at that point all the
writes are failing. If you check the error you receive from logger.Print
you should see something to that effect.

Thomas


On Mon, Feb 5, 2018 at 1:39 PM  wrote:

> I'm initializing a Logger variable in an init() function and then
> attempting to use in the main() function. However, I'm able to Printf from
> the Logger in the init() function but not inside the main() function. Any
> help would be appreciated.
>
> package main
>
> import (
>
> "fmt"
> "log"
> "io"
>
> "os"
>
> }
>
> var (
>
> logFile *os.File
> logger *log.Logger
> multiWriter io.Writer
>
> )
>
> func init() {
>
> fmt.Println("init() function")
>
> var logFileError error
> logFile, logFileError = os.Create("gopoc.log")
> if logFileError != nil {
> panic(logFileError)
> }
> defer logFile.Close()
>
> fmt.Println("Creating log file")
>
> multiWriter = io.MultiWriter(logFile, os.Stdout)
>
> logger = log.New(multiWriter, gopocLogPrefix, log.Ldate | log.Ltime |
> log.Lshortfile)
> logger.SetOutput(multiWriter)
>
> fmt.Println("Created logger")
>
> logger.Printf("Using logger")  // prints to console and logFile as expected
>
> }
>
> func main() {
>
> fmt.Println("main() function ") // prints to console
>
> fmt.Println(logger) // I can see the object pointer
>
> logger.Print("hello") // This does not print to logFile nor
> os.Stdout !!!
>
> }
>
> --
> You received this message because you are subscribed to the Google Groups
> "golang-nuts" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to golang-nuts+unsubscr...@googlegroups.com.
> For more options, visit https://groups.google.com/d/optout.
>

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[go-nuts] Global variable initialized in init() not working in main()

[mbrizic]

I'm initializing a Logger variable in an init() function and then 
attempting to use in the main() function. However, I'm able to Printf from 
the Logger in the init() function but not inside the main() function. Any 
help would be appreciated.

package main

import (

"fmt"
"log"
"io"

"os"

}

var (

logFile *os.File 
logger *log.Logger
multiWriter io.Writer

)

func init() {

fmt.Println("init() function")

var logFileError error
logFile, logFileError = os.Create("gopoc.log")
if logFileError != nil {
panic(logFileError)
}
defer logFile.Close()

fmt.Println("Creating log file")

multiWriter = io.MultiWriter(logFile, os.Stdout)

logger = log.New(multiWriter, gopocLogPrefix, log.Ldate | log.Ltime | 
log.Lshortfile)
logger.SetOutput(multiWriter)

fmt.Println("Created logger")

logger.Printf("Using logger")  // prints to console and logFile as expected

}

func main() {

fmt.Println("main() function ") // prints to console

fmt.Println(logger) // I can see the object pointer

logger.Print("hello") // This does not print to logFile nor 
os.Stdout !!!

}

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