CONTROL
- Introduction to CTRL
- CONTROL Classes
- Types of Control Functions
- CONTROL graphics
- CONTROL Functions
  - Funtions A
  - Funtions B
  - Funtions C
  - Funtions D
  - Functions E
  - Functions F
    - fclose()
      Closes a file.
    - folderSelector()
      Opens the folder selector dialog and writes the name of the selected folder to the string variable "path".
    - fileSelector()
      Opens the file selection dialog and writes the selected file name to fileName.
    - fscanfPL()
      Reads a file similar to fscanf() except changes to the current WinCC OA language before converting.
    - floor()
      Rounds down to an integer.
    - findExecutable()
      The function searches for the given executable and returns the full path to it or an empty string if not found.
    - fwrite()
      Writes a number of bytes from a blob variable to a file.
    - fprintfPL()
      Writes to a file similar to fprintf() except changes to the current WinCC OA language before converting.
    - fseek()
      Sets the pointer of the file f from the position whence to the position defined by the offset.
    - formatTimeUTC()
      Returns the UTC time in a particular format.
    - fabs()
      Returns the absolute value of x.
    - fflush()
      Writes data to a file.
    - fprintf()
      Writes to a file.
    - fswAddPath()
      The functions add a path for monitoring to the FileSystemWatcher.
    - formatDebug()
      Similar to the function Debug() but instead of writing to the log viewer returns the debug messages as string,.
    - fmod()
    - formatTime()
      Returns the time in a particular format.
    - fscanf()
      Reads a file.
    - fillSelector()
      Opens the filling pattern selector and writes the selection to a variable.
    - fileToString()
      This function loads an ASCII file and writes the contents into a string variable.
    - fontSelector()
      Opens the font type selector and writes the selection to a variable.
    - fopen()
      Opens a file.
    - feof()
      Examines whether an end of file has been noted.
    - formatSelector()
      Opens the format selector and writes the string format that has been selected on the format string variable.
    - fread()
      Reads a number of bytes from a file to a blob variable.
    - fscanfUL()
      Reads a file like fscanf(), but change to the current Windows user language before converting.
    - fileEditor()
      Opens text files such as .txt and .doc files in an editor. You can edit both plain and rich text.
    - fputs()
      Writes a string to a file.
    - fprintfUL()
      Writes to a file similar to fprintf() except changes to the current Windows user language before converting.
    - fgets()
      Returns a string from a file.
    - ftell()
      The ftell function obtains the current value of the file position indicator for the stream pointed to by f.
    - ferror()
      Examines whether a file error has been noted.
    - fswRemovePath()
      The function removes a path from the monitoring of the FileSystemWatcher.
  - Functions G
  - Functions H
  - Functions I
  - Functions J
  - Functions K
  - Functions L
  - Functions M
  - Functions N
  - Functions O
  - Functions P
  - Functions Q
  - Functions R
  - Functions S
  - Functions T
  - Functions U
  - Functions V
  - Functions W
  - Functions X
  - Functions Y
  - Functions Z
- CTRL Debugger
  With the CTRL Debugger you can debug the programming language Control.

fopen()

Opens a file.

Synopsis

file fopen( string filename, string mode );

Parameters


Parameter	Description
filename	File to be opened.
mode	mode

Return value

The function fopen() returns a file pointer or returns 0 if unsuccessful.

Error

Missing or wrong arguments.

Description

The function fopen() opens the file with the specified name. The file can be accessed with the return value using further file functions. The following modes exist:


mode	Meaning
r	Open existing file for reading
w	Create file for writing. If a file with the given name already exists, its contents will be lost.
a	Create file for writing. If a file with the given name already exists, the new text will be appended at the end.
r+	Open file for reading and writing.
rb	Binary Read
w+	Create file for writing and reading. If a file with the given name already exists, its contents will be lost.
wb	Write a binary file.
wb+	Create a binary file for writing and reading.
a+	Create file for writing and reading. If a file with the given name already exists, the new text will be appended at the end.

Please consider that the encoding of the stated filename must match the current codepage of the operating system.
To prevent possible change to the line ending encoding the parameter "w" should be used instead of "wb".

Example

The following example opens a binary file for writing and editing. Furthermore, the file is opened in the file editor.

main()
{
  file f;
// our file
  int err;
// error code
  string fileName = tmpnam();
  f = fopen(fileName, "wb+");
//Open a binary file for writing and reading
  err = ferror(f);
//Output possible errors
  if ( err )
  {
    DebugN("Error no. ",err," occurred");
    return;
  }
  string content = "This is my file \n";
  fputs(content, f);
//Write to the file
  fclose(f);
//Close file


  fileEditor(fileName, FALSE);
//Open the file in the file editor
  remove(fileName);
}

Assignment

File function

Availability

CTRL