GET$ runs a satellite program and returns the contents of a file

Syntax

GET$(FileName$, Process$, [InpVar])

Arguments

  • FileName$ is a string expression containing the name of a file of which the contents has to be returned. If FileName$ does not contain a path, the file is assumed to be present on the current Quaestor Report directory.
  • Process$ is a name of satellite program to be invoked, e.g. producing FileName$ as output file. If Process$="NullString" or "", no program is started and simply the contents of file FileName$ is returned. If Process$ does not contain a path, the program is assumed to be present on the current Quaestor Applications directory.
  • InpVar is an optional list of parameters or functions. The list may contain one or more PUT$() function calls which writing data to input file(s) required by Process$.

Remarks

  1. The GET$ function can be used in two ways; either to retrieve data from an existing file, or to run another program that generates a file from which GET$ retrieves data into a TeLiTab.
  2. GET$() is an alternative for GET$ as it returns ALL output in file FileName$ in the form of a single string. The result can be assigned to a string parameter which in its term can be used as data source Telitab$ for other functions such as interpolation or integration. GET$() can be used with programs using and producing Telitab data but also by those working with file IO in an arbitrary format. GET$ checks the necessity of rerunning a program by comparing the current input with previous input. GET$() always reruns without comparing previous with new input. GET$() in combination with TEMPLATE$() and PUT$() is comparable with GET$ using an input template, viz. a structural recipe for the (single) input file. GET$() can create multiple input files each using their own template ( TEMPLATE$() ).
  3. Please note that the Process$ can be the execution of a batch file that is carrying out several command line actions. Furthermore, this batch file itself can be generated knowledge based by means of a PUT$() combined with a TEMPLATE$() action. Using the report path where the batch file is saved in the Process$ (use SYSTEMVAR$() to request the path from Quaestor) the approach enables many programs and processes to be executed in a very flexible way. Look on the internet and documentation of the processes you want to execute about detailed possibilities.
  4. Furthermore, please realise that you can use the @COPYFIRST attribute to make sure some required external files are copied to the working directory prior to running the program specified in the GET$. Furthermore, when you add the process itself to the @COPYFIRST Quaestor will remove any path information given in front of the process in the GET$ function.

Examples

Example 1: Retrieving data from a file

Using the relation:

A$ = GET$("DATAFILE.DAT","")

If the file DATAFILE.DAT contains:

0
2 "XC" "YC"
"1" 1 1
"2" 2 4
"3" 3 9
"4" 4 16
"5" 5 25
"6" 6 36
"7" 7 49
"8" 8 64
"9" 9 81
"10" 10 100

The string A$ will contain the TeLiTab:

0
2 "XC" "YC"
"1" 1 1
"2" 2 4
"3" 3 9
"4" 4 16
"5" 5 25
"6" 6 36
"7" 7 49
"8" 8 64
"9" 9 81
"10" 10 100

Example 2: Running a satellite program (combination with PUT$)

Let the relation OUTPUT$ be defined by 

OUTPUT$ = GET$("OUTPUT.EPO", "SATTELITE_PROGRAM.EXE", PUT$("INPUT.EPI",INPUT$))

This relation results in the following:

An input string (INPUT$) is placed in an input file (INPUT.EPI). This file will be used by the process (SATTELITE_PROGRAM.EXE) to generate an output file (OUTPUT.EPO). This output file is then brought into Quaestor as an output string (OUTPUT$). Within Quaestor, this string or TeLiTab can be used for all kinds of purposes.

Example 3: Executing an embedded file

The relation

A$ = GET$("NullString", "NullString")

Embed a Binary by means of selecting the relation and right click select: "Include Binary in frame...". When A$ is requested, the embedded content is assumed to be an executable file. If the embedded object has the ".EXE" extension, this executable is started without expecting an output file.

 

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