lancet/docs/system.md

# System
Package system contains some functions about os, runtime, shell command.

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## Source:

- [https://github.com/duke-git/lancet/blob/main/system/os.go](https://github.com/duke-git/lancet/blob/main/system/os.go)


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## Usage:
```go
import (
    "github.com/duke-git/lancet/v2/system"
)
```

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## Index
- [IsWindows](#IsWindows)
- [IsLinux](#IsLinux)
- [IsMac](#IsMac)
- [GetOsEnv](#GetOsEnv)
- [SetOsEnv](#SetOsEnv)
- [RemoveOsEnv](#RemoveOsEnv)
- [CompareOsEnv](#CompareOsEnv)
- [ExecCommand](#ExecCommand)
- [GetOsBits](#GetOsBits)
  

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## Documentation


### <span id="IsWindows">IsWindows</span>
<p>Check if current os is windows.</p>

<b>Signature:</b>

```go
func IsWindows() bool
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/v2/system"
)

func main() {
	isOsWindows := system.IsWindows()
	fmt.Println(isOsWindows)
}
```




### <span id="IsLinux">IsLinux</span>
<p>Check if current os is linux.</p>

<b>Signature:</b>

```go
func IsLinux() bool
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/v2/system"
)

func main() {
	isOsLinux := system.IsLinux()
	fmt.Println(isOsLinux)
}
```



### <span id="IsMac">IsMac</span>
<p>Check if current os is macos.</p>

<b>Signature:</b>

```go
func IsMac() bool
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/v2/system"
)

func main() {
	isOsMac := system.IsMac
	fmt.Println(isOsMac)
}
```



### <span id="GetOsEnv">GetOsEnv</span>
<p>Gets the value of the environment variable named by the key.</p>

<b>Signature:</b>

```go
func GetOsEnv(key string) string
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/v2/system"
)

func main() {
	fooEnv := system.GetOsEnv("foo")
	fmt.Println(fooEnv)
}
```



### <span id="SetOsEnv">SetOsEnv</span>
<p>Sets the value of the environment variable named by the key.</p>

<b>Signature:</b>

```go
func SetOsEnv(key, value string) error
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/v2/system"
)

func main() {
	err := system.SetOsEnv("foo", "foo_value")
	fmt.Println(err)
}
```




### <span id="RemoveOsEnv">RemoveOsEnv</span>
<p>Remove a single environment variable.</p>

<b>Signature:</b>

```go
func RemoveOsEnv(key string) error
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/v2/system"
)

func main() {
	err := system.RemoveOsEnv("foo")
	if err != nil {
		fmt.Println(err)
	}
}
```



### <span id="CompareOsEnv">CompareOsEnv</span>
<p>Get env named by the key and compare it with comparedEnv.</p>

<b>Signature:</b>

```go
func CompareOsEnv(key, comparedEnv string) bool
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/v2/system"
)

func main() {
	system.SetOsEnv("foo", "foo_value")
	res := system.CompareOsEnv("foo", "foo_value")
	fmt.Println(res) //true
}
```




### <span id="ExecCommand">CompareOsEnv</span>
<p>Execute shell command, return the stdout and stderr string of command, and error if error occur. param `command` is a complete command string, like, ls -a (linux), dir(windows), ping 127.0.0.1. In linux, use /bin/bash -c to execute command, In windows, use powershell.exe to execute command.</p>

<b>Signature:</b>

```go
func ExecCommand(command string) (stdout, stderr string, err error)
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/v2/system"
)

func main() {
	// linux or mac
	stdout, stderr, err := system.ExecCommand("ls")
	fmt.Println("std out: ", stdout)
	fmt.Println("std err: ", stderr)
	assert.Equal("", stderr)

	// windows
	stdout, stderr, err = system.ExecCommand("dir")
	fmt.Println("std out: ", stdout)
	fmt.Println("std err: ", stderr)

	// error command
	stdout, stderr, err = system.ExecCommand("abc")
	fmt.Println("std out: ", stdout)
	fmt.Println("std err: ", stderr)
	if err != nil {
		fmt.Println(err.Error())
	}
}
```




### <span id="GetOsBits">GetOsBits</span>
<p>Get current os bits, 32bit or 64bit. return 32 or 64</p>

<b>Signature:</b>

```go
func GetOsBits() int
```
<b>Example:</b>

```go
import (
	"fmt"
	"github.com/duke-git/lancet/v2/system"
)

func main() {
	osBit := system.GetOsBits()
	fmt.Println(osBit) 
}
```