1. Error in Go: package_mytest.go:5:2: cannot find package “.” in: E:\wwwroot\go\the-way-to-go\package\pack1. As shown in Figure 1
Plaintext
PS E:\wwwroot\go\the-way-to-go\package> go run .\package_mytest.go
package_mytest.go:5:2: cannot find package "." in:
E:\wwwroot\go\the-way-to-go\package\pack1
2. View the code of pack1.go
Go
package pack1
var Pack1Int int = 42
var pack1Float = 3.14
func ReturnStr() string {
return "Hello main!"
}
3. View the code of package_mytest.go
Go
package main
import (
"fmt"
"./pack1"
)
func main() {
var test1 string
test1 = pack1.ReturnStr()
fmt.Printf("ReturnStr from package1: %s\n", test1)
fmt.Printf("Integer from package1: %d\n", pack1.Pack1Int)
// fmt.Printf("Float from package1: %f\n", pack1.pack1Float)
}
4. View environment variables – Administrator’s user variables – GOPATH, its value is: C:\Users\Administrator\go, as shown in Figure 2
5. Compile and install a package. Copy pcak1.go to C:\Users\Administrator\go\src\pack1\pack1.go. Compile and install the package locally via the command: go install pack1, this will copy pack1.a to C:\Users\Administrator\go\pkg\windows_amd64. As shown in Figure 3
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PS C:\Users\Administrator\go> cd .\src\pack1\
PS C:\Users\Administrator\go\src\pack1> ls
Directory: C:\Users\Administrator\go\src\pack1
Mode LastWriteTime Length Name
---- ------------- ------ ----
-a---- 2020/06/23 19:23 114 pack1.go
PS C:\Users\Administrator\go\src\pack1> go install pack1
PS C:\Users\Administrator\go\src\pack1> cd ..
PS C:\Users\Administrator\go\src> cd ..
PS C:\Users\Administrator\go> cd .\pkg\windows_amd64\
PS C:\Users\Administrator\go\pkg\windows_amd64> ls
Directory: C:\Users\Administrator\go\pkg\windows_amd64
Mode LastWriteTime Length Name
---- ------------- ------ ----
d----- 2019/12/27 17:01 golang.org
-a---- 2020/07/02 19:30 1216 pack1.a
-a---- 2020/07/02 19:20 1592 uc.a
6. Run: go run .\package_mytest.go, executed successfully, changing “./pack1” to “pack1” also executes successfully. As shown in Figure 4
Plaintext
PS E:\wwwroot\go\the-way-to-go\package> go run .\package_mytest.go
ReturnStr from package1: Hello main!
Integer from package1: 42