Storing all the values of a PPM P3 file - c

Question

I am "attempting" to store P3 PPM files using C but I'm not all that experienced with it so I've hit a brick wall. I was wondering if anyone could help me in accomplishing my task. Thank you.
I would like to keep them as struct PPM and struct PPM * getPPM(File * fd) but the contents can be altered.
I also don't know how to store the comments and would like to do that too.
Basically I am trying to store the data as follows:
P3
#comment.1
. . .
#comment.n
width height
max
r1 g1 b1
r2 g2 b2
r3 g3 b3
. . .
Edit:
I have done the changes for it to compile correctly and now I am trying to pass argv so that the file may read argv[1] to get the file name. When I do so i receive a Segmentation error.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
//Holds the data
struct data {int r,g,b;};
struct PPM {char code[4]; char comments; int width; int height; int max; struct data *Data;};
//Gets the PPM data
struct PPM* GetPPM(FILE * fd, argv)
{
char readChars[256] = {0};
//Allocates memory for PPM
struct PPM *image = (struct PPM *)calloc(1, sizeof(struct PPM));
int i;
fgets(image->code, sizeof(image->code), fd);
fd = fopen(argv[1], "r");
//Checks if file is type P3
if((image->code[0] != 'P') && (image->code[0] != '3'))
{
return NULL;
}
image->code[2] = '\0';
//Checks for comments then continues around the loop until there's no more
fgets(readChars, sizeof(readChars), fd);
while(readChars[0] == '#')
{
fgets(readChars, sizeof(readChars), fd);
}
//Checks for PPM width, height and max
sscanf(readChars, "%d %d", &image->width, &image->height);
fgets(readChars, sizeof(readChars), fd);
sscanf(readChars, "%d", &image->max);
image->Data = (struct data*)malloc(image->width * image->height * sizeof(struct data));
i = 0;
while(fgets(readChars, sizeof(readChars), fd));
{
sscanf(readChars, "%d %d %d", &(image->Data[i].r), &(image->Data[i].g), &(image->Data[i].b));
++i;
}
fclose(fd);
return image;
}
//Deallocates memory
void freePPM(struct PPM *image)
{
free(image->Data);
free(image);
}
//Displays PPM
void showPPM(struct PPM *image)
{
int i = 0;
int totalpixels = image->width * image->height;
printf("%s\n", image->code);
printf("%d %d\n", image->width, image->height);
printf("%d\n", image->max);
for(i = 0; i < totalpixels; ++i)
{
printf("%d %d %d\n", image->Data[i].r, image->Data[i].g, image->Data[i].b);
}
}
int main(int argc, char ** argv)
{
struct PPM *image = GetPPM(argv);
showPPM(image);
freePPM(image);
return 0;
}

Answer 1

There are some error in declaring structures and the way data is read. Check how the data is read in the following code and come back here if you want more clarity.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct data {int r,g,b;};
struct PPM {char code[4]; char comments; int width; int height; int max; struct data *Data;};
struct PPM* GetPPM(FILE * fd)
{
char readChars[256] = {0};
struct PPM *image = (struct PPM *)calloc(1, sizeof(struct PPM));
int i;
fgets(image->code, sizeof(image->code), stdin);
if((image->code[0] != 'P') && (image->code[0] != '3'))
{
return NULL;
}
image->code[2] = '\0';
fgets(readChars, sizeof(readChars), stdin);
while(readChars[0] == '#')
{
fgets(readChars, sizeof(readChars), stdin);
}
sscanf(readChars, "%d %d", &image->width, &image->height);
fgets(readChars, sizeof(readChars), stdin);
sscanf(readChars, "%d", &image->max);
image->Data = (struct data*)malloc(image->width * image->height * sizeof(struct data));
i = 0;
while(fgets(readChars, sizeof(readChars), stdin))
{
sscanf(readChars, "%d %d %d", &(image->Data[i].r), &(image->Data[i].g), &(image->Data[i].b));
++i;
}
return image;
}
void FreePPM(struct PPM *image)
{
free(image->Data);
free(image);
}
void PrintPPM(struct PPM *image)
{
int i = 0;
int totalpixels = image->width * image->height;
printf("%s\n", image->code);
printf("%d %d\n", image->width, image->height);
printf("%d\n", image->max);
for(i = 0; i < totalpixels; ++i)
{
printf("%d %d %d\n", image->Data[i].r, image->Data[i].g, image->Data[i].b);
}
}
int main()
{
struct PPM *image = GetPPM(stdin);
PrintPPM(image);
FreePPM(image);
return 0;
}