├── .gitignore ├── LICENSE ├── README.md ├── examples ├── bash.go └── cat-random.go ├── exec.go └── iexec.go /.gitignore: -------------------------------------------------------------------------------- 1 | # Binaries for programs and plugins 2 | *.exe 3 | *.dll 4 | *.so 5 | *.dylib 6 | 7 | # Test binary, build with `go test -c` 8 | *.test 9 | 10 | # Output of the go coverage tool, specifically when used with LiteIDE 11 | *.out 12 | 13 | # Project-local glide cache, RE: https://github.com/Masterminds/glide/issues/736 14 | .glide/ 15 | -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | Apache License 2 | Version 2.0, January 2004 3 | http://www.apache.org/licenses/ 4 | 5 | TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 6 | 7 | 1. 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We also recommend that a 185 | file or class name and description of purpose be included on the 186 | same "printed page" as the copyright notice for easier 187 | identification within third-party archives. 188 | 189 | Copyright {yyyy} {name of copyright owner} 190 | 191 | Licensed under the Apache License, Version 2.0 (the "License"); 192 | you may not use this file except in compliance with the License. 193 | You may obtain a copy of the License at 194 | 195 | http://www.apache.org/licenses/LICENSE-2.0 196 | 197 | Unless required by applicable law or agreed to in writing, software 198 | distributed under the License is distributed on an "AS IS" BASIS, 199 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 200 | See the License for the specific language governing permissions and 201 | limitations under the License. 202 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | [![GoDoc](https://godoc.org/github.com/adlane/exec?status.png)](https://godoc.org/github.com/adlane/exec) 2 | 3 | # exec 4 | A golang package to interact with a process running in background 5 | 6 | ### Example 7 | 8 | ```go 9 | package main 10 | 11 | import ( 12 | "fmt" 13 | "time" 14 | 15 | "github.com/adlane/exec" 16 | ) 17 | 18 | func main() { 19 | ctx := exec.InteractiveExec("bash", "-i") 20 | r := reader{} 21 | go ctx.Receive(&r, 5*time.Second) 22 | ctx.Send("echo hello world\n") 23 | time.Sleep(time.Second) 24 | ctx.Send("ls\n") 25 | time.Sleep(time.Second) 26 | } 27 | 28 | type reader struct { 29 | } 30 | 31 | func (*reader) OnData(b []byte) bool { 32 | fmt.Print(string(b)) 33 | return false 34 | } 35 | 36 | func (*reader) OnError(b []byte) bool { 37 | fmt.Print(string(b)) 38 | return false 39 | } 40 | 41 | func (*reader) OnTimeout() {} 42 | ``` 43 | 44 | ### Output 45 | 46 | ```bash 47 | $ echo hello world 48 | hello world 49 | $ ls 50 | bash.go 51 | cat-random.go 52 | ``` 53 | -------------------------------------------------------------------------------- /examples/bash.go: -------------------------------------------------------------------------------- 1 | package main 2 | 3 | import ( 4 | "fmt" 5 | "time" 6 | 7 | "github.com/adlane/exec" 8 | ) 9 | 10 | func main() { 11 | ctx := exec.InteractiveExec("bash", "-i") 12 | r := reader{} 13 | go ctx.Receive(&r, 5*time.Second) 14 | ctx.Send("echo hello world\n") 15 | time.Sleep(time.Second) 16 | ctx.Send("ls\n") 17 | time.Sleep(time.Second) 18 | } 19 | 20 | type reader struct { 21 | } 22 | 23 | func (*reader) OnData(b []byte) bool { 24 | fmt.Print(string(b)) 25 | return false 26 | } 27 | 28 | func (*reader) OnError(b []byte) bool { 29 | fmt.Print(string(b)) 30 | return false 31 | } 32 | 33 | func (*reader) OnTimeout() {} 34 | -------------------------------------------------------------------------------- /examples/cat-random.go: -------------------------------------------------------------------------------- 1 | package main 2 | 3 | import ( 4 | "log" 5 | "time" 6 | 7 | "github.com/adlane/exec" 8 | ) 9 | 10 | func main() { 11 | if os, err := exec.TimeoutedExec(time.Second, "cat", "/dev/urandom"); err != nil { 12 | log.Fatal("command failed:", err) 13 | } else { 14 | log.Printf("%x\n", os) 15 | } 16 | } 17 | -------------------------------------------------------------------------------- /exec.go: -------------------------------------------------------------------------------- 1 | package exec 2 | 3 | import ( 4 | "bytes" 5 | "errors" 6 | "os" 7 | "os/exec" 8 | "time" 9 | ) 10 | 11 | // TimeoutedExec executes a timeouted command. 12 | // The program path is defined by the name arguments, args are passed as arguments to the program. 13 | // 14 | // TimeoutedExec returns process output as a string (stdout) , and stderr as an error. 15 | func TimeoutedExec(timeout time.Duration, name string, args ...string) (string, error) { 16 | c := exec.Command(name, args...) 17 | stdout := &bytes.Buffer{} 18 | stderr := &bytes.Buffer{} 19 | c.Stdout = stdout 20 | c.Stderr = stderr 21 | 22 | if err := c.Start(); err != nil { 23 | return "", err 24 | } 25 | 26 | done := make(chan error, 1) 27 | go func() { 28 | _, err := c.Process.Wait() 29 | done <- err 30 | }() 31 | select { 32 | case <-time.After(timeout): 33 | c.Process.Signal(os.Kill) 34 | case <-done: 35 | } 36 | 37 | res := string(stdout.Bytes()) 38 | if err := string(stderr.Bytes()); len(err) > 0 { 39 | return res, errors.New(err) 40 | } 41 | return res, nil 42 | } 43 | -------------------------------------------------------------------------------- /iexec.go: -------------------------------------------------------------------------------- 1 | package exec 2 | 3 | import ( 4 | "bytes" 5 | "io" 6 | "os/exec" 7 | "time" 8 | ) 9 | 10 | const ( 11 | minRead = 4096 12 | ) 13 | 14 | // InteractiveExec executes a process and keep it running in background, while providing functions to write to and read from process ios (stdin, stdout, stderr). 15 | // The program path is defined by the name arguments, args are passed as arguments to the program. 16 | // 17 | // TimeoutedExec returns process execution context. 18 | func InteractiveExec(name string, args ...string) ProcessContext { 19 | res := &processContext{} 20 | res.proc = exec.Command(name, args...) 21 | res.stdout = newStdio() 22 | res.stderr = newStdio() 23 | res.stdin = newStdio() 24 | res.cancel = make(chan struct{}, 1) 25 | 26 | res.proc.Stdout = res.stdout 27 | res.proc.Stderr = res.stderr 28 | res.proc.Stdin = res.stdin 29 | 30 | go res.proc.Run() 31 | 32 | return res 33 | } 34 | 35 | // Process context interface defines how to interact with a running process in the background 36 | type ProcessContext interface { 37 | // Read from the running process output streams (stdout and stderr) 38 | Receive(stdReader Reader, timeout time.Duration) 39 | 40 | // Stop the running process and release resources 41 | Stop() error 42 | 43 | // Cancel current receive 44 | Cancel() 45 | 46 | // Write to the running process input stream (stdin) 47 | Send(s string) error 48 | } 49 | 50 | // Reader interface provides a list of callbacks that will be called during a ProcessContext.Receive call. 51 | type Reader interface { 52 | // Called when new data is ready to read on the running process stdout stream 53 | OnData(b []byte) bool 54 | 55 | // Called when new data is ready to read on the running process stderr stream 56 | OnError(b []byte) bool 57 | 58 | // Called on ProcessContext.Receive timeout 59 | OnTimeout() 60 | } 61 | 62 | type processContext struct { 63 | proc *exec.Cmd 64 | stdin *stdio 65 | stdout *stdio 66 | stderr *stdio 67 | cancel chan struct{} 68 | } 69 | 70 | // Receive data from the running process (stdout, stderr) 71 | func (p *processContext) Receive(stdReader Reader, timeout time.Duration) { 72 | t := time.Now() 73 | deadline := t.Add(timeout) 74 | 75 | stop := false 76 | for { 77 | select { 78 | case <-time.After(timeout): 79 | if stdReader != nil { 80 | stdReader.OnTimeout() 81 | } 82 | stop = true 83 | case <-p.stdout.ready: 84 | if b := p.stdout.readAll(); len(b) > 0 { 85 | if stdReader != nil { 86 | stop = stdReader.OnData(b) 87 | } 88 | } 89 | case <-p.stderr.ready: 90 | if b := p.stderr.readAll(); len(b) > 0 { 91 | if stdReader != nil { 92 | stop = stdReader.OnError(b) 93 | } 94 | } 95 | case <-p.cancel: 96 | stop = true 97 | } 98 | 99 | t = time.Now() 100 | if t.After(deadline) { 101 | stop = true 102 | } else { 103 | timeout = deadline.Sub(t) 104 | } 105 | 106 | if stop { 107 | break 108 | } 109 | } 110 | } 111 | 112 | // Stop process and release resources 113 | func (p *processContext) Stop() error { 114 | return p.proc.Process.Kill() 115 | } 116 | 117 | // Cancel current receive 118 | func (p *processContext) Cancel() { 119 | p.cancel <- struct{}{} 120 | } 121 | 122 | // Send text to the running process (stdin) 123 | func (p *processContext) Send(s string) error { 124 | if _, err := p.stdin.buf.Write([]byte(s)); err != nil { 125 | return err 126 | } else { 127 | p.stdin.ready <- err 128 | } 129 | return nil 130 | } 131 | 132 | type stdio struct { 133 | buf bytes.Buffer 134 | ready chan error 135 | } 136 | 137 | func newStdio() *stdio { 138 | res := &stdio{} 139 | res.buf.Grow(minRead) 140 | res.ready = make(chan error, 10) 141 | return res 142 | } 143 | 144 | func (p *stdio) readAll() []byte { 145 | res := []byte{} 146 | for b := p.buf.Next(minRead); len(b) > 0; b = p.buf.Next(minRead) { 147 | res = append(res, b...) 148 | } 149 | return res 150 | } 151 | 152 | // stdout, stderr 153 | func (p *stdio) ReadFrom(r io.Reader) (n int64, err error) { 154 | b := make([]byte, minRead) 155 | readSize := 0 156 | for { 157 | readSize, err = r.Read(b) 158 | n += int64(readSize) 159 | if readSize > 0 { 160 | p.buf.Write(b[:readSize]) 161 | } 162 | p.ready <- err 163 | if err != nil { 164 | if err == io.EOF { 165 | return n, nil 166 | } 167 | return 168 | } 169 | } 170 | } 171 | 172 | // stdin 173 | func (p *stdio) WriteTo(w io.Writer) (n int64, err error) { 174 | for { 175 | select { 176 | case <-p.ready: 177 | w.Write(p.readAll()) 178 | } 179 | } 180 | } 181 | 182 | // ------------------------------------------------------------------------ 183 | // Should not be called 184 | // ------------------------------------------------------------------------ 185 | func (p *stdio) Read(b []byte) (n int, err error) { 186 | n, err = p.buf.Read(b) 187 | if err == io.EOF { 188 | return n, nil 189 | } 190 | return n, err 191 | } 192 | 193 | func (p *stdio) Write(b []byte) (n int, err error) { 194 | n, err = p.buf.Write(b) 195 | if p.ready != nil { 196 | p.ready <- err 197 | } 198 | return n, err 199 | } 200 | --------------------------------------------------------------------------------