CODEWITHSUNDEEP
cprintfscanf
Gregory Gould
Gregory Gould

Reputation: 11

sscanf is not working as intended

So I'm writing a program for my class and I have a line read in from a text file as follows: 

while (fgets(line, sizeof(line), file) != NULL)

That gets from a text file and I've been using line[index] matching a character to get specific lines from that text file.

The text file line looks as follows; 

dbr:Edmonton    rdf:type    yago:WikicatTownsInAlberta ,

I've been using sscanf to get specific data from each line.

sscanf(line,"%s %s %s %s",triple[t][0],triple[t][1],triple[t][2],triple[t][3]);

Now what I expected to get from this was:

triple[t][0] == dbr:Edmonton 
triple[t][1] == rdf:type 
triple[t][2] == yago:WikicatTownsInAlberta 
triple[t][3] == ,

Instead what my output was:

Object:dbr:rdf:yago, 
Predicate:rdf:yago, 
Subject:yago,
Extraneous: ,

Yet, when I printf(%s,line) I get the line exactly as represented in the file.

This could be totally stupid, but I really hope you can help me.

Cheers,

The entirety of the code is as follows:

#include <stdio.h>
#include <sqlite3.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>

sqlite3 * db;       // THE DATABASE
sqlite3_stmt * stmt;    // THE SQL STATEMENT

int main(int argc, char * argv[])
{
    // Do Argument Stuff, Open Database

int rc;
char * class;
char * data;

if (argc!=3)
{
    printf("Usage: <programfile.c database data>\n");
    printf("You specified %d arguments. You need to specify 3.\n",argc);
    return 1;
}
else
{
    printf("Correct Number of Inputs!\n");
    //printf("Argument %d: %s",argc,argv[0]);
    //printf("Argument %d: %s",argc,argv[1]);
    //printf("Argument %d: %s",argc,argv[2]);

    data = argv[2];
    printf("Data: %s\n",data);
    rc = sqlite3_open(argv[1], &db);
}

// Open File

FILE * file = fopen(data,"r");
if (file == NULL)
{
    printf("ERROR: File open error.\n");
    return 1;
}

/* Read the file */
char line[256];
char prefix[256][200];
char prefixURI[256][200];
char triple[256][200][4];
// object, predicate, subject

while (fgets(line, sizeof(line), file) != NULL)
{
    //printf("%s\n",line);
    int p = 0, t=0;
    // Handle COMMENTS and Blank Lines
    if (line[0] == '#' || line[0] == '\n')
    {
        continue;
    }
    // Handle "@prefix"
    else if (line[0] == '@')
    {
        // Load prefix (rdf: into prefix) and the URI into prefixURI.
        sscanf(line,"@prefix %s %s",prefix[p],prefixURI[p]);
        printf("Prefix Encoded: %s URI: %s\n",prefix[p],prefixURI[p]);
        p++;
    }
    // handle data triples
    else if (line[3] == ':')
    {
        printf("%s",line);
        sscanf(line,"%s %s %s %s",triple[t][0],triple[t][1],triple[t] [2],triple[t][3]);
        printf("Object:%s \nPredicate:%s \nSubject:%s\nExtraneous: %s\n",triple[t][0],triple[t][1],triple[t][2],triple[t][3]);
    }








} // end getWhile Loop


fclose(file);

}

Upvotes: 0

Views: 180

Answers (1)

Sumit Gemini
Sumit Gemini

Reputation: 1836

If str is a character array with more than one row, sscanf reads the characters in column order. you have to replace you else if(line[3]==':') condition

the correct way is :

  // handle data triples
    else if (line[3] == ':')
    {
        printf("%s",line);
        sscanf(line,"%s %s %s %s",triple[0][t],triple[1][t],triple[2] [t],triple[3][t]);
        printf("Object:%s \nPredicate:%s \nSubject:%s\nExtraneous: %s\n",triple[0][t],triple[1][t],triple[2][t],triple[3][t]);
    }

Upvotes: -1

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