Golang processes: Difference between revisions
From wikinotes
Line 65: | Line 65: | ||
} | } | ||
ps := os.StartProcess("netstat", []string{"-a", "-n"}, psAttr) | ps := os.StartProcess("netstat", []string{"-a", "-n"}, psAttr) | ||
pstate, err := ps.Wait() | |||
pstate.ExitCode() | |||
</syntaxhighlight> | </syntaxhighlight> | ||
Line 71: | Line 73: | ||
import "os/exec" | import "os/exec" | ||
// high-level | // high-level | ||
// 1. create command, | // 1. create command, | ||
// 2. modify it's exec.Cmd struct (ex. stdin,stdout) | // 2. modify it's exec.Cmd struct (ex. stdin,stdout) |
Revision as of 12:46, 26 June 2022
TODO:
- signal handling
- safely reading from stdin
- piping outputs to inputs
- what about exit codes?
Documentation
os
https://pkg.go.dev/os@go1.18.3
Current Process
import "os" import "os/user" os.Executable() os.Getpid() os.Getppid() os.Getuid() os.Getgid() os.Exit(1) // exit process with exitcode '1' // environment envvars := os.Environ() // ["FOO=bar", "BAR=baz", ...] pwd, err := os.Getwd() // get current pwd/cwd user.Current() // 'will'
Manage Processes
import "syscall" import "os" import "os/signal" proc := os.Process.FindProcess(1234) // find process with pid proc.Kill() // kill process (-9/SIGKILL) proc.Signal(os.Iterrupt) // send SIGINT to process (looks like you can use any syscall.SIG*) proc.Wait() // wait for process to end syscall.Kill(1234, syscall.SIGINT) // send SIGINT to pid 1234
Subprocess
import "os" import "os/exec" // low-level (inherited files, os-specific syscalls, etc.) // likely want exec.* instead psAttr := os.ProcAttr{ Dir: "/var/tmp", Env: []string{"FOO=BAR"}, } ps := os.StartProcess("netstat", []string{"-a", "-n"}, psAttr) pstate, err := ps.Wait() pstate.ExitCode()import "os" import "os/exec" // high-level // 1. create command, // 2. modify it's exec.Cmd struct (ex. stdin,stdout) // 3. cmd.Start() cmd := exec.Command("netstat", "-an") stdout, err := cmd.Output() reader, err := cmd.StderrPipe() reader, err := cmd.StdoutPipe() writer, err := cmd.StdinPipe() err := cmd.Run() // run and wait err := cmd.Start() // run, don't wait err := cmd.Wait() // wait for proces to finish