Thread: Structure file input

I am having problems reading in lines from a .bat file or text file into an array of structures and outputing the array of structures to a different file. It is reading garbage for some fields of the array of structures. How do I properly read in lines of data from a file into an array of structures?

This is some of my code:

Code:

#include <stdio.h>

#define MAXPTS 20
#define MAXNAME 10

struct coord
{
   int x;
   int y;
};

struct navtag
{
   int id;
   char name[MAXNAME];
   struct coord pts;
   float depth;
};

void getData(FILE *ifp, struct navtag navrec[]);
void printData(FILE *ofp, struct navtag navrec[]);

int main()
{
   FILE *ifp, *ofp;
   int n;

   struct navtag navrec[MAXPTS];
   getData(ifp,navrec);
   printData(ofp,navrec);



	return 0;
}

void getData(FILE *ifp, struct navtag navrec[])
{
   int x;
	ifp=fopen("c:\\lab4.dat", "r");
	for(x=0; x<MAXPTS; x++)
   {
	fscanf(ifp,"%d", &navrec[x].id);
	fscanf(ifp,"%s", &navrec[x].name);
	fscanf(ifp,"%d", &navrec[x].pts.x);
	fscanf(ifp,"%d", &navrec[x].pts.y);
	fscanf(ifp,"%f\n", &navrec[x].depth);
   }

   fclose(ifp);

   return;
}


void printData(FILE *ofp, struct navtag navrec[])
{
int x;
ofp=fopen("c:\\lab4.out", "w");
for(x=0; x<MAXPTS; x++)
{
	fprintf(ofp,"point = %d\n", navrec[x].id);
	fprintf(ofp,"      name is %s\n", navrec[x].name);
		fprintf(ofp,"      location is x = %d, y = %d\n ", navrec[x].pts.x,navrec[x].pts.y);
	fprintf(ofp,"      depth = %f\n", navrec[x].depth);
}
fclose(ofp);
return;
}

//here is the lab4.dat file
100 Pt. Jones 10 -70 6.27
105 Pt. Smith 5 28 3.23
110 Pt. Brown -3 -17 10.48
115 Pt. Ruiz 42 -5 8.64
120 Pt. Alman -12 35 14.76
125 Pt. Aloha 23 8 20.19
130 Pt. Club 18 -53 18.67
135 Pt. Marks 13 45 17.55
140 Pt. Hart 33 -21 1.47
145 Pt. Jacob -14 17 5.74
150 Pt. Miser 25 -36 7.89
155 Pt. Mixup 88 56 6.54
160 Pt. Fling -7 64 2.38
165 Pt. Blank -2 -32 9.99
170 Pt. Hope 9 -2 14.34
175 Pt. Bass 34 25 19.88
180 Pt. Slim 40 -12 8.77
185 Pt. Slick -6 16 13.41
190 Pt. Lock -1 38 5.65
195 Pt. Easy 0 10 3.00
//Here is the output I get to the file lab4.out
point = 100
      name is Pt.
      location is x = -1184335880, y = -34821
       depth = -199679.984375
point = -815630342
      name is Jones
      location is x = 10, y = -70
       depth = 6.270000
point = 105
      name is Pt.
      location is x = -784203776, y = -2055995159
       depth = 0.000000
point = -1005845735
      name is Smith
      location is x = 5, y = 28
       depth = 3.230000
point = 110
      name is Pt.
      location is x = 1386151950, y = 2
       depth = 0.000000
point = 1990197248
      name is Brown
      location is x = -3, y = -17
       depth = 10.480000
point = 115
      name is Pt.
      location is x = -264306625, y = 889485303
       depth = 0.000000
point = -26738688
      name is Ruiz
      location is x = 42, y = -5
       depth = 8.640000
point = 120
      name is Pt.
      location is x = 786434, y = 1835008
       depth = 0.000000
point = 258211840
      name is Alman
      location is x = -12, y = 35
       depth = 14.760000
point = 125
      name is Pt.
      location is x = 721122, y = 0
       depth = -8704265901225330058000000000.000000
point = 27
      name is Aloha
      location is x = 23, y = 8
       depth = 20.190001
point = 130
      name is Pt.
      location is x = 1027110901, y = 1703956
       depth = -167482727468899400000000000000000000000.0
point = 109838354
      name is Club
      location is x = 18, y = -53
       depth = 18.670000
point = 135
      name is Pt.
      location is x = 434862054, y = 30694
       depth = -223310303291865866600000000000000000000.0
point = -1623719918
      name is Marks
      location is x = 13, y = 45
       depth = 17.549999
point = 140
      name is Pt.
      location is x = 131072, y = -4718592
       depth = 859471996918968111600000.000000
point = 131136
      name is Hart
      location is x = 33, y = -21
       depth = 1.470000
point = 145
      name is Pt.
      location is x = -8388544, y = 1097072658
       depth = 0.000000
point = 0
      name is Jacob
      location is x = -14, y = 17
       depth = 5.740000

[code][/code]tagged by Salem

A few remarks:

The filepointers in main() are unnecessary, move them to the functions which use the filepointers, main() does not need them. Especially since you're closing the files in the functions which use the pointers.

In the functions which use the filepointers, you should add a check which checks if the file is opened. If the file could not be opened, then the filepointer has value NULL after fopen.

Using fscanf is not very safe. I'd recommend to use fgets() to read a line from the into a buffer and then use this buffer to fill in the structure.

The same counts for fprintf. Fill a buffer and write this buffer to the file using fputs().