String reading (Scilab gateway)
How to read matrices of strings in a gateway.
Syntax
Input argument profile:
SciErr getMatrixOfString(void* _pvCtx, int* _piAddress, int* _piRows, int* _piCols, int* _piLength, char** _pstStrings)
SciErr getMatrixOfWideString(void* _pvCtx, int* _piAddress, int* _piRows, int* _piCols, int* _piLength, wchar_t** _pwstStrings)
Named variable profile:
SciErr createNamedMatrixOfString(void* _pvCtx, const char* _pstName, int _iRows, int _iCols, char** _pstStrings)
SciErr createNamedMatrixOfWideString(void* _pvCtx, const char* _pstName, int _iRows, int _iCols, wchar_t** _pwstStrings)
Arguments
- _pvCtx
Scilab environment pointer, pass in "pvApiCtx" provided by api_scilab.h.
- _piAddress
Address of the Scilab variable.
- _pstName
Name of the variable for "named" functions.
- _piRows
Return number of rows.
- _piCols
Return number of columns.
- _piLength
Address of array of strings length (must be allocated size: _piRows * _piCols)
- _pstStrings
Address of array of char* (must be allocated size: _piRows * _piCols)
- _pwstStrings
Address of array of wchar_t* (must be allocated size: _piRows * _piCols)
- SciErr
Error structure where is stored errors messages history and first error number.
Description
This help describes how matrix of strings can be handled through the Scilab API.
Gateway Source
#include "api_scilab.h" int read_string(char *fname,void* pvApiCtx) { SciErr sciErr; int i,j; int iLen = 0; //variable info int iRows = 0; int iCols = 0; int* piAddr = NULL; int* piLen = NULL; char** pstData = NULL; //output variable int iRowsOut = 1; int iColsOut = 1; char* pstOut = NULL; //check input and output arguments CheckInputArgument(pvApiCtx, 1, 1); CheckOutputArgument(pvApiCtx, 0, 1); //get variable address sciErr = getVarAddressFromPosition(pvApiCtx, 1, &piAddr); if(sciErr.iErr) { printError(&sciErr, 0); return 0; } //first call to retrieve dimensions sciErr = getMatrixOfString(pvApiCtx, piAddr, &iRows, &iCols, NULL, NULL); if(sciErr.iErr) { printError(&sciErr, 0); return 0; } piLen = (int*)malloc(sizeof(int) * iRows * iCols); //second call to retrieve length of each string sciErr = getMatrixOfString(pvApiCtx, piAddr, &iRows, &iCols, piLen, NULL); if(sciErr.iErr) { printError(&sciErr, 0); return 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 = getMatrixOfString(pvApiCtx, piAddr, &iRows, &iCols, piLen, pstData); if(sciErr.iErr) { printError(&sciErr, 0); return 0; } //computer length of all strings for(i = 0 ; i < iRows * iCols ; i++) { iLen += piLen[i]; } //alloc output variable pstOut = (char*)malloc(sizeof(char) * (iLen + iRows * iCols)); //initialize string to 0x00 memset(pstOut, 0x00, sizeof(char) * (iLen + iRows * iCols)); //concat input strings in output string for(i = 0 ; i < iRows ; i++) { for(j = 0 ; j < iCols ; j++) { int iCurLen = strlen(pstOut); if(iCurLen) { strcat(pstOut, " "); } strcpy(pstOut + strlen(pstOut), pstData[j * iRows + i]); } } //create new variable sciErr = createMatrixOfString(pvApiCtx, nbInputArgument(pvApiCtx) + 1, iRowsOut, iColsOut, &pstOut); if(sciErr.iErr) { printError(&sciErr, 0); return 0; } //free memory free(piLen); for(i = 0 ; i < iRows * iCols ; i++) { free(pstData[i]); } free(pstData); free(pstOut); AssignOutputVariable(pvApiCtx, 1) = nbInputArgument(pvApiCtx) + 1; return 0; }
Scilab test script
a_ref = ["may the puffin be with you"]; a = ["may", "the", "puffin"; "be","with","you"]; b = read_string(a); if a_ref <> b then error("failed"), end
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