QCFuncElement("CreateMutexEx", CreateMutexExW)
QCFuncElement("CreateSemaphoreEx", CreateSemaphoreExW)
QCFuncElement("FormatMessage", FormatMessageW)
- QCFuncElement("FreeEnvironmentStrings", FreeEnvironmentStringsW)
- QCFuncElement("GetEnvironmentStrings", GetEnvironmentStringsW)
+ QCFuncElement("FreeEnvironmentStringsW", FreeEnvironmentStringsW)
+ QCFuncElement("GetEnvironmentStringsW", GetEnvironmentStringsW)
QCFuncElement("GetEnvironmentVariable", GetEnvironmentVariableW)
QCFuncElement("OpenEvent", OpenEventW)
QCFuncElement("OpenMutex", OpenMutexW)
public static unsafe IDictionary GetEnvironmentVariables()
{
- char* pStrings = Interop.Kernel32.GetEnvironmentStrings();
- if (pStrings == null)
+ // Format for GetEnvironmentStrings is:
+ // [=HiddenVar=value\0]* [Variable=value\0]* \0
+ // See the description of Environment Blocks in MSDN's CreateProcess
+ // page (null-terminated array of null-terminated strings). Note
+ // the =HiddenVar's aren't always at the beginning.
+
+ // Copy strings out, parsing into pairs and inserting into the table.
+ // The first few environment variable entries start with an '='.
+ // The current working directory of every drive (except for those drives
+ // you haven't cd'ed into in your DOS window) are stored in the
+ // environment block (as =C:=pwd) and the program's exit code is
+ // as well (=ExitCode=00000000).
+
+ char* stringPtr = Interop.Kernel32.GetEnvironmentStringsW();
+ if (stringPtr == null)
{
throw new OutOfMemoryException();
}
try
{
- // Format for GetEnvironmentStrings is:
- // [=HiddenVar=value\0]* [Variable=value\0]* \0
- // See the description of Environment Blocks in MSDN's
- // CreateProcess page (null-terminated array of null-terminated strings).
-
- // Search for terminating \0\0 (two unicode \0's).
- char* p = pStrings;
- while (!(*p == '\0' && *(p + 1) == '\0'))
- {
- p++;
- }
- Span<char> block = new Span<char>(pStrings, (int)(p - pStrings + 1));
-
- // Format for GetEnvironmentStrings is:
- // (=HiddenVar=value\0 | Variable=value\0)* \0
- // See the description of Environment Blocks in MSDN's
- // CreateProcess page (null-terminated array of null-terminated strings).
- // Note the =HiddenVar's aren't always at the beginning.
-
- // Copy strings out, parsing into pairs and inserting into the table.
- // The first few environment variable entries start with an '='.
- // The current working directory of every drive (except for those drives
- // you haven't cd'ed into in your DOS window) are stored in the
- // environment block (as =C:=pwd) and the program's exit code is
- // as well (=ExitCode=00000000).
-
var results = new Hashtable();
- for (int i = 0; i < block.Length; i++)
- {
- int startKey = i;
- // Skip to key. On some old OS, the environment block can be corrupted.
- // Some will not have '=', so we need to check for '\0'.
- while (block[i] != '=' && block[i] != '\0')
+ char* currentPtr = stringPtr;
+ while (true)
+ {
+ int variableLength = string.wcslen(currentPtr);
+ if (variableLength == 0)
{
- i++;
+ break;
}
- if (block[i] == '\0')
- {
- continue;
- }
+ var variable = new ReadOnlySpan<char>(currentPtr, variableLength);
- // Skip over environment variables starting with '='
- if (i - startKey == 0)
+ // Find the = separating the key and value. We skip entries that begin with =. We also skip entries that don't
+ // have =, which can happen on some older OSes when the environment block gets corrupted.
+ int i = variable.IndexOf('=');
+ if (i > 0)
{
- while (block[i] != 0)
+ // Add the key and value.
+ string key = new string(variable.Slice(0, i));
+ string value = new string(variable.Slice(i + 1));
+ try
{
- i++;
+ // Add may throw if the environment block was corrupted leading to duplicate entries.
+ // We allow such throws and eat them (rather than proactively checking for duplication)
+ // to provide a non-fatal notification about the corruption.
+ results.Add(key, value);
}
-
- continue;
+ catch (ArgumentException) { }
}
- string key = new string(block.Slice(startKey, i - startKey));
- i++; // skip over '='
-
- int startValue = i;
- while (block[i] != 0)
- {
- i++; // Read to end of this entry
- }
-
- string value = new string(block.Slice(startValue, i - startValue)); // skip over 0 handled by for loop's i++
- try
- {
- results.Add(key, value);
- }
- catch (ArgumentException)
- {
- // Throw and catch intentionally to provide non-fatal notification about corrupted environment block
- }
+ // Move to the end of this variable, after its terminator.
+ currentPtr += variableLength + 1;
}
+
return results;
}
finally
{
- bool success = Interop.Kernel32.FreeEnvironmentStrings(pStrings);
- Debug.Assert(success);
+ Interop.BOOL success = Interop.Kernel32.FreeEnvironmentStringsW(stringPtr);
+ Debug.Assert(success != Interop.BOOL.FALSE);
}
}
}
projects / platform / upstream / dotnet / runtime.git / commitdiff