testenv_notwin.go

     1  // Copyright 2016 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  //go:build !windows
     6  
     7  package testenv
     8  
     9  import (
    10  	"fmt"
    11  	"os"
    12  	"path/filepath"
    13  	"runtime"
    14  	"sync"
    15  )
    16  
    17  var hasSymlink = sync.OnceValues(func() (ok bool, reason string) {
    18  	switch runtime.GOOS {
    19  	case "plan9":
    20  		return false, ""
    21  	case "android", "wasip1":
    22  		// For wasip1, some runtimes forbid absolute symlinks,
    23  		// or symlinks that escape the current working directory.
    24  		// Perform a simple test to see whether the runtime
    25  		// supports symlinks or not. If we get a permission
    26  		// error, the runtime does not support symlinks.
    27  		dir, err := os.MkdirTemp("", "")
    28  		if err != nil {
    29  			return false, ""
    30  		}
    31  		defer func() {
    32  			_ = os.RemoveAll(dir)
    33  		}()
    34  		fpath := filepath.Join(dir, "testfile.txt")
    35  		if err := os.WriteFile(fpath, nil, 0644); err != nil {
    36  			return false, ""
    37  		}
    38  		if err := os.Symlink(fpath, filepath.Join(dir, "testlink")); err != nil {
    39  			if SyscallIsNotSupported(err) {
    40  				return false, fmt.Sprintf("symlinks unsupported: %s", err.Error())
    41  			}
    42  			return false, ""
    43  		}
    44  	}
    45  
    46  	return true, ""
    47  })
    48
View as plain text