How do I send a ppm to a function in another file

#include "transform.h"

int print(void){

    FILE *inFile


    inFile = fopen("tiger.ppm", "r");
    if(!inFile){
        fprintf(stderr, "File open error. Exiting program\n");
        exit(1);
    }
}

#include "transform.h"


int main (int argc, char *argv[])  {

    // declarations here
    FILE *inFile;



    // open input file
    inFile = fopen("tiger.ppm", "r")
    if (inFile == NULL){
        fprintf(stderr,"Output failure. Exiting program\n");
        exit(2);
    }


    // parseHeader function call here
    parseHeader();

    // malloc space for the array (example given in assignment write-up)
    struct pixel * image = (struct pixel *) malloc(sizeof(struct pixel) *       g_width * g_height);


    // parseImage function call here
    parseImage();

    // close input file
    fclose(inFile);


    // manipulate the image according to command-line parameter
    //      1: mirror image
    //      2: upside down image
    //      3: rotate to the right 90 degrees

    if(argv[1]){

        mirror();
    }
    if else(argv[2]){

        flipHorz();
    }
    if else (argv[3]){

        rotate();
    }



    return 0;
}