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mirror of https://github.com/google/gops.git synced 2024-11-24 08:22:25 +02:00
gops/main.go
2017-09-04 23:05:17 -07:00

139 lines
3.1 KiB
Go

// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Program gops is a tool to list currently running Go processes.
package main
import (
"bytes"
"fmt"
"os"
"regexp"
"strconv"
"strings"
"github.com/google/gops/goprocess"
)
const helpText = `Usage: gops is a tool to list and diagnose Go processes.
Commands:
stack Prints the stack trace.
gc Runs the garbage collector and blocks until successful.
memstats Prints the allocation and garbage collection stats.
version Prints the Go version used to build the program.
stats Prints the vital runtime stats.
help Prints this help text.
Profiling commands:
trace Runs the runtime tracer for 5 secs and launches "go tool trace".
pprof-heap Reads the heap profile and launches "go tool pprof".
pprof-cpu Reads the CPU profile and launches "go tool pprof".
All commands require the agent running on the Go process.
Symbol "*" indicates the process runs the agent.`
// TODO(jbd): add link that explains the use of agent.
func main() {
if len(os.Args) < 2 {
processes()
return
}
cmd := os.Args[1]
if cmd == "help" {
usage("")
}
if len(os.Args) < 3 {
usage("missing PID or address")
}
fn, ok := cmds[cmd]
if !ok {
usage("unknown subcommand")
}
addr, err := targetToAddr(os.Args[2])
if err != nil {
fmt.Fprintf(os.Stderr, "Couldn't resolve addr or pid %v to TCPAddress: %v\n", os.Args[2], err)
os.Exit(1)
}
if err := fn(*addr); err != nil {
fmt.Fprintf(os.Stderr, "%v\n", err)
os.Exit(1)
}
}
func processes() {
ps := goprocess.FindAll()
var maxPID, maxPPID, maxExec, maxVersion int
for i, p := range ps {
ps[i].BuildVersion = shortenVersion(p.BuildVersion)
maxPID = max(maxPID, len(strconv.Itoa(p.PID)))
maxPPID = max(maxPPID, len(strconv.Itoa(p.PPID)))
maxExec = max(maxExec, len(p.Exec))
maxVersion = max(maxVersion, len(ps[i].BuildVersion))
}
for _, p := range ps {
buf := bytes.NewBuffer(nil)
pid := strconv.Itoa(p.PID)
fmt.Fprint(buf, pad(pid, maxPID))
fmt.Fprint(buf, " ")
ppid := strconv.Itoa(p.PPID)
fmt.Fprint(buf, pad(ppid, maxPPID))
fmt.Fprint(buf, " ")
fmt.Fprint(buf, pad(p.Exec, maxExec))
if p.Agent {
fmt.Fprint(buf, "*")
} else {
fmt.Fprint(buf, " ")
}
fmt.Fprint(buf, " ")
fmt.Fprint(buf, pad(p.BuildVersion, maxVersion))
fmt.Fprint(buf, " ")
fmt.Fprint(buf, p.Path)
fmt.Fprintln(buf)
buf.WriteTo(os.Stdout)
}
}
var develRe = regexp.MustCompile(`devel\s+\+\w+`)
func shortenVersion(v string) string {
if !strings.HasPrefix(v, "devel") {
return v
}
results := develRe.FindAllString(v, 1)
if len(results) == 0 {
return v
}
return results[0]
}
func usage(msg string) {
if msg != "" {
fmt.Printf("gops: %v\n", msg)
}
fmt.Fprintf(os.Stderr, "%v\n", helpText)
os.Exit(1)
}
func pad(s string, total int) string {
if len(s) >= total {
return s
}
return s + strings.Repeat(" ", total-len(s))
}
func max(i, j int) int {
if i > j {
return i
}
return j
}