DOKK / manpages / debian 12 / libmatio-doc / Mat_Rewind.3.en
MAT_REWIND(3) Library Functions Manual MAT_REWIND(3)

Mat_Rewind — Rewinds an open MAT file to the beginning.

#include <matio.h>

int
Mat_Rewind(mat_t *matfp);

Rewinds an open MAT file so that () or () reads the first variable in the file.

The function returns 0 on success, or -1 on failure.

The following example shows a list of variables in the MAT file, and prompts the user for the index of the variable to read. If the index is valid, the file is reset to the beginning, and variables read until the selected index is reached.

#include <stdlib.h>
#include <stdio.h>
#include "matio.h"

int
main(int argc, char **argv)
{
    mat_t    *matfp;
    matvar_t *matvar;
    int       idx, num_variables;

    matfp = Mat_Open(argv[1], MAT_ACC_RDONLY);
    if ( NULL == matfp ) {
        fprintf(stderr, "Error opening MAT file %s0, argv[1]);
        return EXIT_FAILURE;
    }

    idx = 0;
    while ( NULL != (matvar = Mat_VarReadNextInfo(matfp)) ) {
        idx++;
        printf("%3d. %s0, idx, matvar->name);
        Mat_VarFree(matvar);
    }
    num_variables = idx;
    if ( num_variables > 0 ) {
        printf("Which variable would you like to read? ");
        if ( 0 == fscanf(stdin,"%d",&idx) ) {
            printf("Invalid variable selection!0);
        } else if ( idx < 1 || idx > num_variables ) {
            fprintf(stderr, "That is an invalid variable index!0);
        } else {
            int k;
            Mat_Rewind(matfp);
            for ( k = 1; k < idx; k++ ) {
                matvar = Mat_VarReadNextInfo(matfp);
                Mat_VarFree(matvar);
            }
            matvar = Mat_VarReadNext(matfp);
            Mat_VarPrint(matvar, 1);
            Mat_VarFree(matvar);
        }
    }

    Mat_Close(matfp);
    return EXIT_SUCCESS;
}

Mat_Open(3), Mat_Close(3), Mat_VarReadNext(3), Mat_VarReadNextInfo(3), Mat_VarPrint(3)

September 12, 2019 Debian