User Manual¶

Run Gosh¶

Automatically installing `goimports` (>= v0.3.0)¶

Note

We recommend that you install goimports to $PATH in advance.

Installing automatically if the command is not found in $PATH.
However, the time until the installation is complete in this case, you will be waiting for the launch of “Gosh” process.

Check version¶

$GOPATH/bin/gosh -version
version: v0.x.x

Basic mode¶

$GOPATH/bin/gosh
go version go1.3.3 linux/amd64

Gosh v0.x.x
Copyright (C) 2014,2015 Kouhei Maeda
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software, and you are welcome to redistribute it.
There is NO WARRANTY, to the extent permitted by law.
>>>

Debug mode¶

$GOPATH/bin/gosh -d

Sudo mode (>= v0.3.0)¶

Warning

The gosh runs sudo -E go run $tmppath/gosh-?????????/gosh_tmp.go in this mode. Be careful your code, don’t run the dangerous code. There is no warranty for this free software. See also the GPLv3 LICENSE.

You can use sudo mode -s option when Your code requires the privilege, for example using ICMP echo request.:

$GOPATH/bin/gosh -s="sudopassword"

Terminate Gosh¶

Enter Ctrl+D:

>>> [gosh] terminated
$

Execute main function¶

Go syntax validly:

>>> package main
>>> import "fmt"
>>> func main() {
>>> fmt.Println("hello")
>>> }
hello
>>>

Omit `package`, `import` statement, `main func`¶

Gosh supports omitting as follows;

“package” statement
“import” statement for standard libraries
“func main” signature

So users give the same results with the following.:

>>> fmt.Println("hello")
hello
>>>

`fmt.Print*` are executed only once¶

>>> i:=1
>>> for i < 3 {
>>> fmt.Println(i)
>>> i++
>>> }

This omit main func is equivalent to the main func not following omitted.:

>>> func main() {
>>> i:=1
>>> for i < 3 {
>>> fmt.Println(i)
>>> i++
>>> }
>>> }

But, fmt.Print* are executed only once.:

>>> fmt.Println(1)
1
>>> fmt.Println(2)
2

This fmt.Print* are removed main body after executing main function.

Reset declaration of main func¶

Execute follow command.:

>>> func main() {}

For example, test function(),:

>>> func test() {
>>> fmt.Println("hello")
>>> }

Execute test() twice,:

>>> test()
hello
>>> test()
hello
hello

This is equivalent to the main func not following omitted.:

>>> func main() {
>>> test()
>>> test()
>>> }

So, print “hello” once after reset main.:

>>> test()
hello
>>> func main() {}
>>> test()
hello

Import packages¶

Gosh supports imports 3rd party libraryies. Gosh enter the import "package", Gosh executes go get and installs the package into the $GOPATH of Gosh process.

For example of using the some package.:

>>> import "example.org/somepkg"
>>> resp, _ := http.Get("http://example.org/some")
>>> defer resp.Body.Close()
>>> payload, _ := somepkg.Reader(resp.Body)
>>> fmt.Println(payload)
(print some payload)

Users are able to omit import “net/http” package that is Go standard library.

If users import the same package, Gosh ignores duplicate import, adn treats as import of only once.

Declaration of type¶

Gosh supoorts declaration of type.:

>>> type foo struct {
>>> msg string
>>> cnt int
>>> }
>>> f := foo{"hello", 0}
>>> for f.cnt < 3 {
>>> fmt.Println(f.msg)
>>> f.cnt++
>>> }
hello
hello
hello
>>>

Gosh supports re-declarations of type. (>= v0.3.0)

Declaration of function¶

Gosh supports declaration of function.:

>>> func test(msg string) bool {
>>> if strings.HasPrefix(msg, "Hello") {
>>> return true
>>> }
>>> return false
>>> }
>>> fmt.Println(test("helo"))
false
>>> fmt.Println(test("hello"))
false
>>> fmt.Println(test("Hello"))
true

Gosh supports re-declarations of function.:

>>> func bar() {
>>> fmt.Println("hello")
>>> }
>>> bar()
hello
>>> func bar() {
>>> fmt.Println("bye")
>>> }
>>> bar()
bye
bye