#C file peek length how to#
#C file peek length code#

To add the common language runtime support compiler option, follow these steps:Ĭlick Project, and then click Properties.

#C file peek length code#

In Visual C++, you must add the common language runtime support compiler option ( /clr:oldSyntax) to successfully compile the previous code sample as managed C++. ListBox1->Items->Add(reader->ReadLine()) StreamReader *reader=new StreamReader(textFile) String* textFile = String::Concat(windir, (S'\mytest.txt')) There are many ways to determine when the end of the file is reached this sample uses the Peek method to examine the next line before reading it. The try.catch block is used to alert the program if the file is empty. The contents of the file are added to a ListBox control. The following sample code uses a StreamReader class to read a text file.

#C file peek length how to#

The Step-by-step example section describes how to create a sample program that demonstrates the following six file I/O operations: The examples in this article describe basic file I/O operations. NET Framework, offer functionality that isn't available with the FileSystemObject, without the overhead of the Interop layer. However, the File class, the FileInfo class, the Directory, DirectoryInfo classes, and other related classes in the.

NET Framework generates a wrapper for the component for you if you want to use it. NET Framework requires that access to the object be through the Interop layer. Because the FileSystemObject is a Component Object Model (COM) component, the. You can still use the FileSystemObject in the. To make the transition easier, see How To Use FileSystemObject with Visual Basic.įor a Visual C#. NET Framework is similar to the FileSystemObject that is popular with many Visual Studio developers. NET Framework, you'll find that the object model for file operations in the. Original product version: Visual C++ Original KB number: 307398 Summary This article describes how to do basic file input/output (I/O) operations in Microsoft Visual C++ or in Visual C++. peekLine ( line ) = true doAssert line = 'the second line' strm. readLine ( line ) = true doAssert line = 'The first line' doAssert strm. peekLine ( line ) = true # not 'the second line' doAssert line = 'The first line' doAssert strm. peekLine ( line ) = true doAssert line = 'The first line' doAssert strm. If false is returned line contains no new data.Įxample: var strm = newStringStream ( 'The first line the second line the third line' ) var line = '' doAssert strm. Returns false if the end of the file has been reached, true otherwise. The newline character(s) are not part of the returned string. line must not be nil! May throw an IO exception.Ī line of text may be delimited by CR, LF or CRLF. Peeks a line of text from the stream s into line. StreamObj = object of RootObj closeImpl * : proc ( s : Stream ) close ( ) # Output: # The first line # the second line # the third line See also Read file stream example: import std / streams var strm = newFileStream ( 'somefile.txt', fmRead ) var line = '' if not isNil ( strm ) : while strm. close ( ) # Output (somefile.txt): # The first line # the second line # the third line Write file stream example: import std / streams var strm = newFileStream ( 'somefile.txt', fmWrite ) var line = '' if not isNil ( strm ) : strm. readLine ( line ) : echo line # Output: # The first line # the second line # the third line strm. The third line''' ) var line = '' while strm. StringStream example import std / streams var strm = newStringStream ( '''The first line Other modules may provide other implementations for this standard stream interface. This module provides a stream interface and two implementations thereof: the FileStream and the StringStream which implement the stream interface for Nim file objects ( File) and strings.

writeData(s: Stream buffer: pointer bufLen: int).readStr(s: Stream length: int str: var string).readStr(s: Stream length: int): string.readLine(s: Stream line: var string): bool.readDataStr(s: Stream buffer: var string slice: Slice): int.readData(s: Stream buffer: pointer bufLen: int): int.peekStr(s: Stream length: int str: var string).peekStr(s: Stream length: int): string.peekLine(s: Stream line: var string): bool.peekData(s: Stream buffer: pointer bufLen: int): int.openFileStream(filename: string mode: FileMode = fmRead bufSize: int = -1): owned.newStringStream(s: sink string = ''): owned StringStream.newFileStream(filename: string mode: FileMode = fmRead bufSize: int = -1): owned.newFileStream(f: File): owned FileStream.