Name

String management — How to manage Scilab's String read and write process using call_scilab and api_scilab

Description

This help describes how strings and matrix of strings can be handle through the Call Scilab API and api Scilab.

There are several functions which can be used to read / write from the memory of Scilab. These functions are described in dedicated pages.

Note: Access to variables is done through api Scilab (named variable).

Examples

 
// This example shows how to write a Scilab string in Scilab engine
// It is the equivalent to A="my Message"; in Scilab interpretor
// See: modules/call_scilab/examples/basicExamples/readwritestring.c

// StartScilab
int row = 1, col = 1; /* Size of the matrix */
/* Declare the string */
char **myMatrixOfString = (char**)malloc(sizeof(char*) * row * col);
myMatrixOfString[0]="my Message";
char variableName[] = "A";
SciErr sciErr;

/* Write it into Scilab's memory */
sciErr = createNamedMatrixOfString(pvApiCtx, variableName, row, col, myMatrixOfString);
if(sciErr.iErr)
{
	printError(&sciErr, 0);
}

/*
 * Prior to Scilab 5.2
 * C2F(cwritechain)(variableName, &sizeOfMyString  , myString, strlen(variableName), sizeOfMyString); 
*/

printf("Display from Scilab of A:\n");
SendScilabJob("disp(A);"); /* Display A */
 
 
/* Load the previously set variable A */
// See: modules/call_scilab/examples/basicExamples/readwritestring.c


char variableToBeRetrieved[]="A";
int iRows       = 0;
int iCols       = 0;
int i,j;
int* piAddr     = NULL;
int* piLen      = NULL;
char** pstData  = NULL;
SciErr sciErr;

//fisrt call to retrieve dimensions
sciErr = readNamedMatrixOfString(pvApiCtx,variableToBeRetrieved,&iRows, &iCols, NULL, NULL);
if(sciErr.iErr)
{
	printError(&sciErr, 0);
}

piLen = (int*)malloc(sizeof(int) * iRows * iCols);
//second call to retrieve length of each string
sciErr = readNamedMatrixOfString(pvApiCtx,variableToBeRetrieved, &iRows, &iCols, piLen, NULL);
if(sciErr.iErr)
{
	printError(&sciErr, 0);
}

pstData = (char**)malloc(sizeof(char*) * iRows * iCols);
for(i = 0 ; i < iRows * iCols ; i++)
	{
		pstData[i] = (char*)malloc(sizeof(char) * (piLen[i] + 1));//+ 1 for null termination
	}
//third call to retrieve data
sciErr = readNamedMatrixOfString(pvApiCtx, variableToBeRetrieved, &iRows, &iCols, piLen, pstData);
if(sciErr.iErr)
{
	printError(&sciErr, 0);
}

printf("\n");
printf("Load and display of A:\n");
for(j = 0 ; j < iCols ; j++)
{
	for(i = 0 ; i < iRows ; i++)
	{
		/* Display the formated matrix with same scilab indice */
		printf("[%d,%d] = %s\n",j+1,i+1,pstData[j* iRows + i]);
	}
}

printf("\n");
free(piLen);
for(i = 0 ; i < iRows * iCols ; i++)
	{
		free(pstData[i]);
	}
free(pstData);

 

See Also

Call_Scilab,api Scilab, cwritechain, creadchain, SendScilabJob, StartScilab, Call_Scilab: Boolean Management, Call_Scilab: Double Management, API_Scilab: Boolean Reading, API_Scilab: Boolean Writing, API_Scilab: Double Reading, API_Scilab: Double Writing, Complex Management

Authors

Sylvestre Ledru