gdb/common/scoped_fd.h

   1 /* scoped_fd, automatically close a file descriptor
   2
   3    Copyright (C) 2018 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef SCOPED_FD_H
  21 #define SCOPED_FD_H
  22
  23 #include <unistd.h>
  24 #include "filestuff.h"
  25
  26 /* A smart-pointer-like class to automatically close a file descriptor.  */
  27
  28 class scoped_fd
  29 {
  30 public:
  31   explicit scoped_fd (int fd = -1) noexcept : m_fd (fd) {}
  32   ~scoped_fd ()
  33   {
  34     if (m_fd >= 0)
  35       close (m_fd);
  36   }
  37
  38   DISABLE_COPY_AND_ASSIGN (scoped_fd);
  39
  40   int release () noexcept
  41   {
  42     int fd = m_fd;
  43     m_fd = -1;
  44     return fd;
  45   }
  46
  47   /* Like release, but return a gdb_file_up that owns the file
  48      descriptor.  On success, this scoped_fd will be released.  On
  49      failure, return NULL and leave this scoped_fd in possession of
  50      the fd.  */
  51   gdb_file_up to_file (const char *mode) noexcept
  52   {
  53     gdb_file_up result (fdopen (m_fd, mode));
  54     if (result != nullptr)
  55       m_fd = -1;
  56     return result;
  57   }
  58
  59   int get () const noexcept
  60   {
  61     return m_fd;
  62   }
  63
  64 private:
  65   int m_fd;
  66 };
  67
  68 #endif /* SCOPED_FD_H */