What is the most portable/cross-platform way to represent a newline in go/golang? - cross-platform

Question

Currently, to represent a newline in go programs, I use \n. For example:
package main
import "fmt"
func main() {
fmt.Printf("%d is %s \n", 'U', string(85))
}
... will yield 85 is U followed by a newline.
However, this doesn't seem all that cross-platform. Looking at other languages, PHP represents this with a global constant ( PHP_EOL ). Is \n the right way to represent newlines in a cross-platform specific manner in go / golang?

Answer 1

I got curious about this so decided to see what exactly is done by fmt.Println. http://golang.org/src/pkg/fmt/print.go
If you scroll to the very bottom, you'll see an if addnewline where \n is always used. I can't hardly speak for if this is the most "cross-platform" way of doing it, and go was originally tied to linux in the early days, but that's where it is for the std lib.
I was originally going to suggest just using fmt.Fprintln and this might still be valid as if the current functionality isn't appropriate, a bug could be filed and then the code would simply need to be compiled with the latest Go toolchain.

Answer 2

You can always use an OS specific file to declare certain constants. Just like _test.go files are only used when doing go test, the _[os].go are only included when building to that target platform.
Basically you'll need to add the following files:
- main.go
- main_darwin.go // Mac OSX
- main_windows.go // Windows
- main_linux.go // Linux
You can declare a LineBreak constant in each of the main_[os].go files and have your logic in main.go.
The contents of you files would look something like this:
main_darwin.go
package somepkg
const LineBreak = "\n"
main_linux.go
package somepkg
const LineBreak = "\n"
main_windows.go
package somepkg
const LineBreak = "\r\n"
and simply in your main.go file, write the code and refer to LineBreak
main.go
package main
import "fmt"
func main() {
fmt.Printf("%d is %s %s", 'U', string(85), LineBreak)
}

Answer 3

Having the OS determine what the newline character is happens in many contexts to be wrong. What you really want to know is what the "record" separator is and Go assumes that you as the programmer should know that.
Even if the binary runs on Windows, it may be consuming a file from a Unix OS.
Line endings are determined by what the source of the file or document said was a line ending, not the OS the binary is running in.

Answer 4

You can use os.PathSeparator
func main() {
var PS = fmt.Sprintf("%v", os.PathSeparator)
var LineBreak = "\n"
if PS != "/" {
LineBreak = "\r\n"
}
fmt.Printf("Line Break %v", LineBreak)
}
https://play.golang.com/p/UTnBbTJyL9c