Modelica.Utilities.Streams

Information

Library content

Package Streams contains functions to input and output strings to a message window or on files. Note that a string is interpreted and displayed as html text (e.g., with print(..) or error(..)) if it is enclosed with the Modelica html quotation, e.g.,

It is a quality of implementation, whether (a) all tags of html are supported or only a subset, (b) how html tags are interpreted if the output device does not allow to display formatted text.

In the table below an example call to every function is given:

Use functions scanXXX from package Strings to parse a string.

If Real, Integer or Boolean values shall be printed or used in an error message, they have to be first converted to strings with the builtin operator ModelicaReference.Operators.'String()'(...). Example:

  if x < 0 or x > 1 then
     Streams.error("x (= " + String(x) + ") has to be in the range 0 .. 1");
  end if;

Package Content

Name	Description
print	Print string to terminal or file
readFile	Read content of a file and return it in a vector of strings
readLine	Reads a line of text from a file and returns it in a string
countLines	Returns the number of lines in a file
error	Print error message and cancel all actions
close	Close file

Modelica.Utilities.Streams.print

Information

Syntax

Streams.print(string);
Streams.print(string,fileName);

Description

Function print(..) opens automatically the given file, if it is not yet open. If the file does not exist, it is created. If the file does exist, the given string is appended to the file. If this is not desired, call "Files.remove(fileName)" before calling print ("remove(..)" is silent, if the file does not exist). The Modelica environment may close the file whenever appropriate. This can be enforced by calling Streams.close(fileName). After every call of "print(..)" a "new line" is printed automatically.

Example

  Streams.print("x = " + String(x));
  Streams.print("y = " + String(y));
  Streams.print("x = " + String(y), "mytestfile.txt");

See also

Streams, Streams.error, ModelicaReference.Operators.'String()'

Inputs

Name	Description
string	String to be printed
fileName	File where to print (empty string is the terminal)

Modelica.Utilities.Streams.readFile

Information

Syntax

stringVector = Streams.readFile(fileName)

Description

Function readFile(..) opens the given file, reads the complete content, closes the file and returns the content as a vector of strings. Lines are separated by LF or CR-LF; the returned strings do not contain the line separators. Note, a fileName can be defined as URI by using the helper function loadResource.

Inputs

Name	Description
fileName	Name of the file that shall be read

Outputs

Name	Description
stringVector[countLines(fileName)]	Content of file

Modelica.Utilities.Streams.readLine

Information

Syntax

(string, endOfFile) = Streams.readLine(fileName, lineNumber)

Description

Function readLine(..) opens the given file, reads enough of the content to get the requested line, and returns the line as a string. Lines are separated by LF or CR-LF; the returned string does not contain the line separator. The file might remain open after the call.

If lineNumber > countLines(fileName), an empty string is returned and endOfFile=true. Otherwise endOfFile=false.

Inputs

Name	Description
fileName	Name of the file that shall be read
lineNumber	Number of line to read

Outputs

Name	Description
string	Line of text
endOfFile	If true, end-of-file was reached when trying to read line

Modelica.Utilities.Streams.countLines

Information

Syntax

numberOfLines = Streams.countLines(fileName)

Description

Function countLines(..) opens the given file, reads the complete content, closes the file and returns the number of lines. Lines are separated by LF or CR-LF.

Inputs

Name	Description
fileName	Name of the file that shall be read

Outputs

Name	Description
numberOfLines	Number of lines in file

Modelica.Utilities.Streams.error

Information

Syntax

Streams.error(string);

Description

Print the string "string" as error message and cancel all actions. Line breaks are characterized by "\n" in the string.

Example

  Streams.error("x (= " + String(x) + ")\nhas to be in the range 0 .. 1");

See also

Streams, Streams.print, ModelicaReference.Operators.'String()'

Inputs

Name	Description
string	String to be printed to error message window

Modelica.Utilities.Streams.close

Information

Syntax

Streams.close(fileName)

Description

Close file if it is open. Ignore call if file is already closed or does not exist.

Inputs

Name	Description
fileName	Name of the file that shall be closed