/// <summary>
/// Reads until the specified <paramref name="keychar" /> is encountered. <paramref name="keychar" /> will not be included in the returned string.
/// </summary>
/// <param name="reader">A <see cref="TextReader" /> object.</param>
/// <param name="keychar">The <paramref name="reader" /> will advance its position to the character immediately after the next occurrence of this <paramref name="keychar" />.</param>
/// <param name="returnIfKeycharNotFound"><c>true</c> if a string starting from the reader's current position to the end should be returned if no <paramref name="keychar"/> is encountered in reading; <c>false</c> if <c>null</c> should be returned in this situation.</param>
/// <returns>A <see cref="string" /> read from the <see cref="TextReader" /> from its current position to the position of the specified <paramref name="keychar" />, or to the end of the <paramref name="reader"/> if no such <paramref name="keychar"/> is found.</returns>
public static string ReadTo(this TextReader reader, char keychar, bool returnIfKeycharNotFound = true)
{
var sb = StringBuilderCache.Acquire();
int ci;
while ((ci = reader.Read()) != -1)
{
if (ci == keychar)
{
return(StringBuilderCache.GetStringAndRelease(sb));
}
else
{
sb.Append((char)ci);
}
}
if (returnIfKeycharNotFound)
{
return(StringBuilderCache.GetStringAndRelease(sb));
}
else
{
StringBuilderCache.Release(sb);
return(null);
}
}
/// <summary>
/// Reads until the specified <paramref name="keyword" /> is encountered. <paramref name="keyword" /> will be included at the end of the returned string.
/// </summary>
/// <param name="reader">A <see cref="TextReader" /> object.</param>
/// <param name="keyword">The <paramref name="reader" /> will advance its position to the character immediately after the next occurrence of this <paramref name="keyword" />.</param>
/// <param name="returnIfKeywordNotFound"><c>true</c> if a string starting from the reader's current position to the end should be returned if no <paramref name="keyword"/> is encountered in reading; <c>false</c> if <c>null</c> should be returned in this situation.</param>
/// <returns>A <see cref="string" /> read from the <see cref="TextReader" /> from its current position to the position of the specified <paramref name="keyword" /> with <paramref name="keyword"/> at the end of the returned <see cref="string"/>, or to the end of the <paramref name="reader"/> if no such <paramref name="keyword"/> is found.</returns>
public static string ReadAfter(this TextReader reader, string keyword, bool returnIfKeywordNotFound = true)
{
var i = 0;
int ci;
var sb = StringBuilderCache.Acquire();
while ((ci = reader.Read()) != -1)
{
var c = (char)ci;
if (c == keyword[i])
{
++i;
if (i == keyword.Length)
{
sb.Append(keyword);
return(StringBuilderCache.GetStringAndRelease(sb));
}
}
else
{
if (i != 0)
{
sb.Append(keyword.Substring(0, i));
i = 0;
}
if (c == keyword[0])
{
++i;
}
else
{
sb.Append(c);
}
}
}
if (returnIfKeywordNotFound)
{
return(StringBuilderCache.GetStringAndRelease(sb));
}
else
{
StringBuilderCache.Release(sb);
return(null);
}
}
private static async Task <string> InternalReadAllTextAsync(string path, Encoding encoding, CancellationToken cancellationToken)
{
Debug.Assert(!string.IsNullOrEmpty(path));
Debug.Assert(encoding != null);
char[] buffer = null;
StringBuilder sb = null;
StreamReader sr = AsyncStreamReader(path, encoding);
try
{
cancellationToken.ThrowIfCancellationRequested();
sb = StringBuilderCache.Acquire();
buffer = ArrayPool <char> .Shared.Rent(sr.CurrentEncoding.GetMaxCharCount(DefaultBufferSize));
for (;;)
{
int read = await sr.ReadAsync(buffer, 0, buffer.Length).ConfigureAwait(false);
if (read == 0)
{
return(sb.ToString());
}
sb.Append(buffer, 0, read);
cancellationToken.ThrowIfCancellationRequested();
}
}
finally
{
sr.Dispose();
if (buffer != null)
{
ArrayPool <char> .Shared.Return(buffer);
}
if (sb != null)
{
StringBuilderCache.Release(sb);
}
}
}
private void WriteFormatHelper(string format, ParamsArray args, bool appendNewLine)
{
StringBuilder sb =
StringBuilderCache.Acquire((format?.Length ?? 0) + args.Length * 8)
.AppendFormatHelper(null, format !, args); // AppendFormatHelper will appropriately throw ArgumentNullException for a null format
StringBuilder.ChunkEnumerator chunks = sb.GetChunks();
bool more = chunks.MoveNext();
while (more)
{
ReadOnlySpan <char> current = chunks.Current.Span;
more = chunks.MoveNext();
// If final chunk, include the newline if needed
WriteSpan(current, appendNewLine: more?false: appendNewLine);
}
StringBuilderCache.Release(sb);
}
public override string GetCurrentDirectory()
{
StringBuilder sb = StringBuilderCache.Acquire(Interop.mincore.MAX_PATH + 1);
if (Interop.mincore.GetCurrentDirectory(sb.Capacity, sb) == 0)
{
throw Win32Marshal.GetExceptionForLastWin32Error();
}
String currentDirectory = sb.ToString();
// Note that if we have somehow put our command prompt into short
// file name mode (ie, by running edlin or a DOS grep, etc), then
// this will return a short file name.
if (currentDirectory.IndexOf('~') >= 0)
{
int r = Interop.mincore.GetLongPathName(currentDirectory, sb, sb.Capacity);
if (r == 0 || r >= Interop.mincore.MAX_PATH)
{
int errorCode = Marshal.GetLastWin32Error();
if (r >= Interop.mincore.MAX_PATH)
{
errorCode = Interop.mincore.Errors.ERROR_FILENAME_EXCED_RANGE;
}
if (errorCode != Interop.mincore.Errors.ERROR_FILE_NOT_FOUND &&
errorCode != Interop.mincore.Errors.ERROR_PATH_NOT_FOUND &&
errorCode != Interop.mincore.Errors.ERROR_INVALID_FUNCTION && // by design - enough said.
errorCode != Interop.mincore.Errors.ERROR_ACCESS_DENIED)
{
throw Win32Marshal.GetExceptionForWin32Error(errorCode);
}
}
currentDirectory = sb.ToString();
}
StringBuilderCache.Release(sb);
return(currentDirectory);
}
private static string NormalizePath(
string path, bool fullCheck,
int maxPathLength, bool expandShortPaths) // ignored on Unix
{
Debug.Assert(path != null);
if (path.Length == 0)
{
throw new ArgumentException(SR.Arg_PathIllegal);
}
if (fullCheck)
{
PathInternal.CheckInvalidPathChars(path);
// Expand with current directory if necessary
if (!IsPathRooted(path))
{
path = Combine(Interop.libc.getcwd(), path);
}
}
// Remove "//", "/./", and "/../" from the path. We would ideally use realpath
// to do this, but it resolves symlinks, requires that the file actually exist,
// and turns it into a full path, which we only want if fullCheck is true.
// Instead, we do the normalization manually, copying each character to the output,
// except the ones we're removing, such that the builder contains the normalized path
// at the end.
var sb = StringBuilderCache.Acquire(path.Length);
int componentCharCount = 0;
for (int i = 0; i < path.Length; i++)
{
char c = path[i];
if (PathInternal.IsDirectorySeparator(c) && i + 1 < path.Length)
{
componentCharCount = 0;
// Skip this character if it's a directory separator and if the next character is, too,
// e.g. "parent//child" => "parent/child"
if (PathInternal.IsDirectorySeparator(path[i + 1]))
{
continue;
}
// Skip this character and the next if it's referring to the current directory,
// e.g. "parent/./child" =? "parent/child"
if ((i + 2 == path.Length || PathInternal.IsDirectorySeparator(path[i + 2])) &&
path[i + 1] == '.')
{
i++;
continue;
}
// Skip this character and the next two if it's referring to the parent directory,
// e.g. "parent/child/../grandchild" => "parent/grandchild"
if (i + 2 < path.Length &&
(i + 3 == path.Length || PathInternal.IsDirectorySeparator(path[i + 3])) &&
path[i + 1] == '.' && path[i + 2] == '.')
{
// Unwind back to the last slash (and if there isn't one, clear out everything).
int s;
for (s = sb.Length - 1; s >= 0; s--)
{
if (PathInternal.IsDirectorySeparator(sb[s]))
{
sb.Length = s;
break;
}
}
if (s < 0)
{
sb.Length = 0;
}
i += 2;
continue;
}
}
if (++componentCharCount > MaxComponentLength)
{
throw new PathTooLongException(SR.IO_PathTooLong);
}
sb.Append(c);
}
Debug.Assert(sb.Length < path.Length || sb.ToString() == path,
"Either we've removed characters, or the string should be unmodified from the input path.");
if (sb.Length > MaxPath)
{
throw new PathTooLongException(SR.IO_PathTooLong);
}
string result =
sb.Length == 0 ? (fullCheck ? DirectorySeparatorCharAsString : string.Empty) :
sb.Length == path.Length ? path :
sb.ToString();
StringBuilderCache.Release(sb);
return(result);
}
// We rely on Windows to remove relative segments on Windows. This would need to be updated to
// handle the proper rooting on Windows if we for some reason need it.
/// <summary>
/// Try to remove relative segments from the given path (without combining with a root).
/// </summary>
/// <param name="skip">Skip the specified number of characters before evaluating.</param>
internal static string RemoveRelativeSegments(string path, int skip = 0)
{
bool flippedSeparator = false;
// Remove "//", "/./", and "/../" from the path by copying each character to the output,
// except the ones we're removing, such that the builder contains the normalized path
// at the end.
var sb = StringBuilderCache.Acquire(path.Length);
if (skip > 0)
{
sb.Append(path, 0, skip);
}
int componentCharCount = 0;
for (int i = skip; i < path.Length; i++)
{
char c = path[i];
if (PathInternal.IsDirectorySeparator(c) && i + 1 < path.Length)
{
componentCharCount = 0;
// Skip this character if it's a directory separator and if the next character is, too,
// e.g. "parent//child" => "parent/child"
if (PathInternal.IsDirectorySeparator(path[i + 1]))
{
continue;
}
// Skip this character and the next if it's referring to the current directory,
// e.g. "parent/./child" =? "parent/child"
if ((i + 2 == path.Length || PathInternal.IsDirectorySeparator(path[i + 2])) &&
path[i + 1] == '.')
{
i++;
continue;
}
// Skip this character and the next two if it's referring to the parent directory,
// e.g. "parent/child/../grandchild" => "parent/grandchild"
if (i + 2 < path.Length &&
(i + 3 == path.Length || PathInternal.IsDirectorySeparator(path[i + 3])) &&
path[i + 1] == '.' && path[i + 2] == '.')
{
// Unwind back to the last slash (and if there isn't one, clear out everything).
int s;
for (s = sb.Length - 1; s >= 0; s--)
{
if (PathInternal.IsDirectorySeparator(sb[s]))
{
sb.Length = s;
break;
}
}
if (s < 0)
{
sb.Length = 0;
}
i += 2;
continue;
}
}
if (++componentCharCount > PathInternal.MaxComponentLength)
{
throw new PathTooLongException();
}
// Normalize the directory separator if needed
if (c != Path.DirectorySeparatorChar && c == Path.AltDirectorySeparatorChar)
{
c = Path.DirectorySeparatorChar;
flippedSeparator = true;
}
sb.Append(c);
}
if (flippedSeparator || sb.Length != path.Length)
{
return(StringBuilderCache.GetStringAndRelease(sb));
}
else
{
// We haven't changed the source path, return the original
StringBuilderCache.Release(sb);
return(path);
}
}
static string _innerReadToNewlineDelimiter(this TextReader reader, string keyword, bool returnIfKeywordNotFound)
{
var i = 0;
var j = 0;
int ci;
var sb = StringBuilderCache.Acquire();
var delimiter = Environment.NewLine;
bool secondHit = false;
while ((ci = reader.Read()) != -1)
{
var c = (char)ci;
if (c == delimiter[j])
{
++j;
if (j == delimiter.Length)
{
if (secondHit)
{
break;
}
else
{
while ((ci = reader.Read()) != -1 && ci != delimiter[0] && ((char)ci).IsWhiteSpace())
{
;
}
if (ci == -1)
{
break;
}
else if (ci == delimiter[0])
{
secondHit = true;
j = 1;
continue;
}
else
{
c = (char)ci;
}
}
}
}
else if (c == delimiter.Last())
{
while ((ci = reader.Read()) != -1 && ci != delimiter[0] && ((char)ci).IsWhiteSpace())
{
;
}
if (ci == -1)
{
break;
}
else if (ci == delimiter[0])
{
secondHit = true;
j = 1;
continue;
}
else
{
c = (char)ci;
}
}
else
{
if (c == delimiter[0])
{
j = 1;
}
else
{
j = 0;
}
}
if (c == keyword[i])
{
++i;
if (i == keyword.Length)
{
return(StringBuilderCache.GetStringAndRelease(sb));
}
}
else
{
if (i != 0)
{
sb.Append(keyword.Substring(0, i));
i = 0;
}
if (c == keyword[0])
{
++i;
}
else
{
sb.Append(c);
}
}
}
if (returnIfKeywordNotFound)
{
return(StringBuilderCache.GetStringAndRelease(sb));
}
else
{
StringBuilderCache.Release(sb);
return(null);
}
}
public static string ReadTo(this TextReader reader, string keyword, string delimiter, bool returnIfKeywordNotFound = false)
{
if (delimiter == Environment.NewLine)
{
return(_innerReadToNewlineDelimiter(reader, keyword, returnIfKeywordNotFound));
}
var i = 0;
var j = 0;
int ci;
var sb = StringBuilderCache.Acquire();
while ((ci = reader.Read()) != -1)
{
var c = (char)ci;
if (c == delimiter[j])
{
++j;
if (j == delimiter.Length)
{
break;
}
}
else
{
if (c == delimiter[0])
{
j = 1;
}
else
{
j = 0;
}
}
if (c == keyword[i])
{
++i;
if (i == keyword.Length)
{
return(StringBuilderCache.GetStringAndRelease(sb));
}
}
else
{
if (i != 0)
{
sb.Append(keyword.Substring(0, i));
i = 0;
}
if (c == keyword[0])
{
++i;
}
else
{
sb.Append(c);
}
}
}
if (returnIfKeywordNotFound)
{
return(StringBuilderCache.GetStringAndRelease(sb));
}
else
{
StringBuilderCache.Release(sb);
return(null);
}
}