github.com/epfl-dcsl/gotee@v0.0.0-20200909122901-014b35f5e5e9/src/os/exec_posix.go (about)

     1  // Copyright 2009 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // +build darwin dragonfly freebsd linux nacl netbsd openbsd solaris windows
     6  
     7  package os
     8  
     9  import (
    10  	"syscall"
    11  )
    12  
    13  // The only signal values guaranteed to be present in the os package
    14  // on all systems are Interrupt (send the process an interrupt) and
    15  // Kill (force the process to exit). Interrupt is not implemented on
    16  // Windows; using it with os.Process.Signal will return an error.
    17  var (
    18  	Interrupt Signal = syscall.SIGINT
    19  	Kill      Signal = syscall.SIGKILL
    20  )
    21  
    22  func startProcess(name string, argv []string, attr *ProcAttr) (p *Process, err error) {
    23  	// If there is no SysProcAttr (ie. no Chroot or changed
    24  	// UID/GID), double-check existence of the directory we want
    25  	// to chdir into. We can make the error clearer this way.
    26  	if attr != nil && attr.Sys == nil && attr.Dir != "" {
    27  		if _, err := Stat(attr.Dir); err != nil {
    28  			pe := err.(*PathError)
    29  			pe.Op = "chdir"
    30  			return nil, pe
    31  		}
    32  	}
    33  
    34  	sysattr := &syscall.ProcAttr{
    35  		Dir: attr.Dir,
    36  		Env: attr.Env,
    37  		Sys: attr.Sys,
    38  	}
    39  	if sysattr.Env == nil {
    40  		sysattr.Env = Environ()
    41  	}
    42  	for _, f := range attr.Files {
    43  		sysattr.Files = append(sysattr.Files, f.Fd())
    44  	}
    45  
    46  	pid, h, e := syscall.StartProcess(name, argv, sysattr)
    47  	if e != nil {
    48  		return nil, &PathError{"fork/exec", name, e}
    49  	}
    50  	return newProcess(pid, h), nil
    51  }
    52  
    53  func (p *Process) kill() error {
    54  	return p.Signal(Kill)
    55  }
    56  
    57  // ProcessState stores information about a process, as reported by Wait.
    58  type ProcessState struct {
    59  	pid    int                // The process's id.
    60  	status syscall.WaitStatus // System-dependent status info.
    61  	rusage *syscall.Rusage
    62  }
    63  
    64  // Pid returns the process id of the exited process.
    65  func (p *ProcessState) Pid() int {
    66  	return p.pid
    67  }
    68  
    69  func (p *ProcessState) exited() bool {
    70  	return p.status.Exited()
    71  }
    72  
    73  func (p *ProcessState) success() bool {
    74  	return p.status.ExitStatus() == 0
    75  }
    76  
    77  func (p *ProcessState) sys() interface{} {
    78  	return p.status
    79  }
    80  
    81  func (p *ProcessState) sysUsage() interface{} {
    82  	return p.rusage
    83  }
    84  
    85  func (p *ProcessState) String() string {
    86  	if p == nil {
    87  		return "<nil>"
    88  	}
    89  	status := p.Sys().(syscall.WaitStatus)
    90  	res := ""
    91  	switch {
    92  	case status.Exited():
    93  		res = "exit status " + itoa(status.ExitStatus())
    94  	case status.Signaled():
    95  		res = "signal: " + status.Signal().String()
    96  	case status.Stopped():
    97  		res = "stop signal: " + status.StopSignal().String()
    98  		if status.StopSignal() == syscall.SIGTRAP && status.TrapCause() != 0 {
    99  			res += " (trap " + itoa(status.TrapCause()) + ")"
   100  		}
   101  	case status.Continued():
   102  		res = "continued"
   103  	}
   104  	if status.CoreDump() {
   105  		res += " (core dumped)"
   106  	}
   107  	return res
   108  }