libgo/go/syscall/errstr_glibc.go

   1 // errstr_glibc.go -- GNU/Linux and GNU/Hurd specific error strings.
   2
   3 // Copyright 2010 The Go Authors. All rights reserved.
   4 // Use of this source code is governed by a BSD-style
   5 // license that can be found in the LICENSE file.
   6
   7 // We use this rather than errstr.go because on GNU/Linux sterror_r
   8 // returns a pointer to the error message, and may not use buf at all.
   9
  10 // +build hurd linux
  11
  12 package syscall
  13
  14 import "unsafe"
  15
  16 //sysnb strerror_r(errnum int, b []byte) (errstr *byte)
  17 //strerror_r(errnum _C_int, b *byte, len Size_t) *byte
  18
  19 func Errstr(errnum int) string {
  20         a := make([]byte, 128)
  21         p := strerror_r(errnum, a)
  22         b := (*[1000]byte)(unsafe.Pointer(p))
  23         i := 0
  24         for b[i] != 0 {
  25                 i++
  26         }
  27         // Lowercase first letter: Bad -> bad, but STREAM -> STREAM.
  28         if i > 1 && 'A' <= b[0] && b[0] <= 'Z' && 'a' <= b[1] && b[1] <= 'z' {
  29                 c := b[0] + 'a' - 'A'
  30                 return string(c) + string(b[1:i])
  31         }
  32         return string(b[:i])
  33 }