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authorKaren Arutyunov <karen@codesynthesis.com>2016-07-02 17:21:54 +0300
committerKaren Arutyunov <karen@codesynthesis.com>2016-07-07 17:39:46 +0300
commit5b1c20f2315cd7fc624ffd31abdcc03b409bfcb2 (patch)
treec5c7b76dead92292b84586bda1b1256170195c48 /butl/fdstream.cxx
parent15634965e8f0ab753898f5607ba11288556d1235 (diff)
Add cpfile()
Diffstat (limited to 'butl/fdstream.cxx')
-rw-r--r--butl/fdstream.cxx130
1 files changed, 124 insertions, 6 deletions
diff --git a/butl/fdstream.cxx b/butl/fdstream.cxx
index 13becfa..e4d11ba 100644
--- a/butl/fdstream.cxx
+++ b/butl/fdstream.cxx
@@ -5,13 +5,15 @@
#include <butl/fdstream>
#ifndef _WIN32
-# include <fcntl.h> // open(), O_RDWR
-# include <unistd.h> // close(), read(), write()
+# include <fcntl.h> // open(), O_*
+# include <unistd.h> // close(), read(), write()
+# include <sys/stat.h> // S_I*
#else
-# include <io.h> // _close(), _read(), _write(), _setmode(), _sopen()
-# include <share.h> // _SH_DENYNO
-# include <stdio.h> // _fileno(), stdin, stdout, stderr
-# include <fcntl.h> // _O_BINARY, _O_TEXT
+# include <io.h> // _close(), _read(), _write(), _setmode(), _sopen()
+# include <share.h> // _SH_DENYNO
+# include <stdio.h> // _fileno(), stdin, stdout, stderr
+# include <fcntl.h> // _O_*
+# include <sys/stat.h> // S_I*
#endif
#include <system_error>
@@ -147,6 +149,122 @@ namespace butl
// Utility functions
//
+ int
+ fdopen (const path& f, fdopen_mode m, permissions p)
+ {
+ mode_t pf (S_IREAD | S_IWRITE | S_IEXEC);
+
+#ifdef S_IRWXG
+ pf |= S_IRWXG;
+#endif
+
+#ifdef S_IRWXO
+ pf |= S_IRWXO;
+#endif
+
+ pf &= static_cast<mode_t> (p);
+
+ // Return true if the open mode contains a specific flag.
+ //
+ auto mode = [m](fdopen_mode flag) -> bool {return (m & flag) == flag;};
+
+ int of (0);
+ bool in (mode (fdopen_mode::in));
+ bool out (mode (fdopen_mode::out));
+
+#ifndef _WIN32
+
+ if (in && out)
+ of |= O_RDWR;
+ else if (in)
+ of |= O_RDONLY;
+ else if (out)
+ of |= O_WRONLY;
+
+ if (out)
+ {
+ if (mode (fdopen_mode::append))
+ of |= O_APPEND;
+
+ if (mode (fdopen_mode::truncate))
+ of |= O_TRUNC;
+ }
+
+ if (mode (fdopen_mode::create))
+ {
+ of |= O_CREAT;
+
+ if (mode (fdopen_mode::exclusive))
+ of |= O_EXCL;
+ }
+
+#ifdef O_LARGEFILE
+ of |= O_LARGEFILE;
+#endif
+
+ int fd (open (f.string ().c_str (), of, pf));
+
+#else
+
+ if (in && out)
+ of |= _O_RDWR;
+ else if (in)
+ of |= _O_RDONLY;
+ else if (out)
+ of |= _O_WRONLY;
+
+ if (out)
+ {
+ if (mode (fdopen_mode::append))
+ of |= _O_APPEND;
+
+ if (mode (fdopen_mode::truncate))
+ of |= _O_TRUNC;
+ }
+
+ if (mode (fdopen_mode::create))
+ {
+ of |= _O_CREAT;
+
+ if (mode (fdopen_mode::exclusive))
+ of |= _O_EXCL;
+ }
+
+ of |= mode (fdopen_mode::binary) ? _O_BINARY : _O_TEXT;
+
+ // According to Microsoft _sopen() should not change the permissions of an
+ // existing file. Meanwhile it does if we pass them (reproduced on Windows
+ // XP, 7, and 8). And we must pass them if we have _O_CREATE. So we need
+ // to take care of preserving the permissions ourselves. Note that Wine's
+ // implementation of _sopen() works properly.
+ //
+ bool pass_perm (of & _O_CREAT);
+
+ if (pass_perm && file_exists (f))
+ {
+ // If the _O_CREAT flag is set then we need to clear it so that we can
+ // omit the permissions. But if the _O_EXCL flag is set as well we can't
+ // do that as fdopen() wouldn't fail as expected.
+ //
+ if (of & _O_EXCL)
+ throw system_error (EEXIST, system_category ());
+
+ of &= ~_O_CREAT;
+ pass_perm = false;
+ }
+
+ int fd (pass_perm
+ ? _sopen (f.string ().c_str (), of, _SH_DENYNO, pf)
+ : _sopen (f.string ().c_str (), of, _SH_DENYNO));
+
+#endif
+
+ if (fd == -1)
+ throw system_error (errno, system_category ());
+
+ return fd;
+ }
+
#ifndef _WIN32
bool