README
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exechelper is a simple wrapper around standard go 'exec' that tries to follow the spirit of its API closely
Its main features are:
- It allows you to pass strings containing the command you want executed instead of an array of args.
- It's Start() returns an errCh that will get zero or one errors, and be closed after the command has finished running
- You can use the WithXYZ pattern to do things like customize things like Stdout, Stdin, StdError, Dir, and Env variables
Run Examples:
if err := exechelper.Run("go list -m");err != nil {...}
if err := exechelper.Run("go list -m",WithEnv(os.Environs()));err != nil {...}
if err := exechelper.Run("go list -m",WithDir(dir)); err != nil {...}
outputBuffer := bytes.NewBuffer([]byte{})
errBuffer := bytes.NewBuffer([]bytes{})
if err := exechelper.Run("go list -m",WithStdout(outputBuffer),WithStderr(errBuffer));err != nil {...}
Start Examples
ctx,cancel := context.WithCancel(context.Background())
errCh := exechelper.Start(startContext,"spire-server run",WithContext(ctx))
// cancel() - will stop the running cmd if its still running
// <-errCh - provides any error from the Start. Will always have zero or one err, so <-errCh will block until Start has finished
// For non-zero Exit code will return a exec.ExitError
// Note: cancel() will almost always result in a non-zero exit code
Similarly, exechelper.Output(...), exechelper.CombinedOutput(...) are provided.
Documentation
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Overview ¶
Package exechelper provides a wrapper around cmd.Exec that makes it easier to use
Index ¶
- func CombinedOutput(cmdStr string, options ...*Option) ([]byte, error)
- func Output(cmdStr string, options ...*Option) ([]byte, error)
- func Run(cmdStr string, options ...*Option) error
- func Start(cmdStr string, options ...*Option) <-chan error
- type CmdFunc
- type Option
- func CmdOption(cmdFunc CmdFunc) *Option
- func WithArgs(args ...string) *Option
- func WithContext(ctx context.Context) *Option
- func WithDir(dir string) *Option
- func WithEnvKV(envs ...string) *Option
- func WithEnvMap(envMap map[string]string) *Option
- func WithEnvirons(environs ...string) *Option
- func WithStderr(writer io.Writer) *Option
- func WithStdin(reader io.Reader) *Option
- func WithStdout(writer io.Writer) *Option
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func CombinedOutput ¶
CombinedOutput - Creates a exec.Cmd using cmdStr. Runs exec.Cmd.CombinedOutput and returns the resulting output as []byte and error
func Output ¶
Output - Creates a exec.Cmd using cmdStr. Runs exec.Cmd.Output and returns the resulting output as []byte and error
Types ¶
type Option ¶
type Option struct {
// Context - context (if any) for running the exec.Cmd
Context context.Context
// CmdFunc to be applied to the exec.Cmd
CmdOption CmdFunc
}
Option - expresses optional behavior for exec.Cmd
func CmdOption ¶
CmdOption - convenience function for producing an Option that only has an Option.CmdOption
func WithArgs ¶
WithArgs - appends additional args to cmdStr
useful for ensuring correctness when you start from args []string rather than from a cmdStr to be parsed
func WithContext ¶
WithContext - option for setting the context.Context for running the exec.Cmd
func WithDir ¶
WithDir - Option that will create the requested dir if it does not exist and set exec.Cmd.Dir = dir
func WithEnvKV ¶
WithEnvKV - add entries to exec.Cmd as a series key,value pairs in a list of strings Existing instances of 'key' will be overwritten Example: WithEnvKV(key1,value2,key2,value2...)
func WithEnvMap ¶
WithEnvMap - add entries to exec.Cmd from envMap Existing instances of 'key' will be overwritten Example: WithEnvKV(map[string]string{key1:value1,key2:value2})
func WithEnvirons ¶
WithEnvirons - add entries to exec.Cmd.Env as a series of "key=value" strings Example: WithEnvirons("key1=value1","key2=value2",...)
func WithStderr ¶
WithStderr - option to provide a writer to receive exec.Cmd.Stderr
if multiple WithStderr options are received, they are combined with an io.Multiwriter
func WithStdout ¶
WithStdout - option to provide a writer to receive exec.Cmd.Stdout
if multiple WithStdout options are received, they are combined with an io.Multiwriter
Source Files