diff options
Diffstat (limited to 'cmd.go')
| -rw-r--r-- | cmd.go | 184 |
1 files changed, 0 insertions, 184 deletions
@@ -1,184 +0,0 @@ -package main - -// this is a simplified interaction with the excellent -// go-cmd/cmd package to work 'shell' like. - -// in all cases here, STDERR -> STDOUT -// If you want the output from whatever you run -// to be captured like it appears when you see it -// on the command line, this is what this tries to do - -/* - if r := shell.Run([]{"ping", "-c", "3", "localhost"}); r.Error == nil { - if r.Exit == 0 { - log.Println("ran ok") - } else { - log.Println("ran") - } - // all stdout/stderr captured in r.Stdout - } -*/ - -import ( - "errors" - "fmt" - "time" - - "github.com/go-cmd/cmd" - "go.wit.com/log" -) - -func Run(args []string) cmd.Status { - return PwdRun("", args) -} - -// absolutely doesn't echo anything -func PwdRunQuiet(pwd string, args []string) cmd.Status { - var arg0 string - var argx []string - // Check if the slice has at least one element (the command name) - if len(args) == 0 { - var s cmd.Status - s.Error = errors.New("Error: Command slice is empty.") - return s - } - if len(args) == 1 { - // Pass the first element as the command, and the rest as variadic arguments - arg0 = args[0] - } else { - arg0 = args[0] - argx = args[1:] - } - - // Start a long-running process, capture stdout and stderr - findCmd := cmd.NewCmd(arg0, argx...) - if pwd != "" { - findCmd.Dir = pwd - } - statusChan := findCmd.Start() // non-blocking - - ticker := time.NewTicker(2 * time.Second) - - // this is interesting, maybe useful, but wierd, but neat. interesting even - // Print last line of stdout every 2s - go func() { - for range ticker.C { - status := findCmd.Status() - n := len(status.Stdout) - if n != 0 { - fmt.Println(status.Stdout[n-1]) - } - } - }() - - // Stop command after 1 hour - go func() { - <-time.After(1 * time.Hour) - findCmd.Stop() - }() - - // Check if command is done - select { - case finalStatus := <-statusChan: - log.Info("finalStatus =", finalStatus.Exit, finalStatus.Error) - return finalStatus - // done - default: - // no, still running - } - - // Block waiting for command to exit, be stopped, or be killed - finalStatus := <-statusChan - return finalStatus -} - -func blah(cmd []string) { - r := Run(cmd) - log.Info("cmd =", r.Cmd) - log.Info("complete =", r.Complete) - log.Info("exit =", r.Exit) - log.Info("err =", r.Error) - log.Info("len(stdout+stderr) =", len(r.Stdout)) -} - -// run these to see confirm the sytem behaves as expected -func RunTest() { - blah([]string{"ping", "-c", "3", "localhost"}) - blah([]string{"exit", "0"}) - blah([]string{"exit", "-1"}) - blah([]string{"true"}) - blah([]string{"false"}) - blah([]string{"grep", "root", "/etc/", "/proc/cmdline", "/usr/bin/chmod"}) - blah([]string{"grep", "root", "/proc/cmdline"}) - fmt.Sprint("blahdone") -} - -// sets the exec dir if it's sent -// combines stdout and stderr -// echo's output -func PwdRun(pwd string, args []string) cmd.Status { - var save []string // combined stdout & stderr - var arg0 string - var argx []string - // Check if the slice has at least one element (the command name) - if len(args) == 0 { - var s cmd.Status - s.Error = errors.New("Error: Command slice is empty.") - return s - } - if len(args) == 1 { - // Pass the first element as the command, and the rest as variadic arguments - arg0 = args[0] - } else { - arg0 = args[0] - argx = args[1:] - } - - // Disable output buffering, enable streaming - cmdOptions := cmd.Options{ - Buffered: false, - Streaming: true, - } - - // Create Cmd with options - envCmd := cmd.NewCmdOptions(cmdOptions, arg0, argx...) - if pwd != "" { - envCmd.Dir = pwd - } - - // Print STDOUT and STDERR lines streaming from Cmd - doneChan := make(chan struct{}) - go func() { - defer close(doneChan) - // Done when both channels have been closed - // https://dave.cheney.net/2013/04/30/curious-channels - for envCmd.Stdout != nil || envCmd.Stderr != nil { - select { - case line, open := <-envCmd.Stdout: - if !open { - envCmd.Stdout = nil - continue - } - save = append(save, line) - fmt.Println(line) - case line, open := <-envCmd.Stderr: - if !open { - envCmd.Stderr = nil - continue - } - save = append(save, line) - fmt.Println(line) - } - } - }() - - // Run and wait for Cmd to return, discard Status - <-envCmd.Start() - - // Wait for goroutine to print everything - <-doneChan - - s := envCmd.Status() - s.Stdout = save - return s -} |