Segmentation Fault:11 Error messages in C Terminal - c

Question

While compiling in the terminal I keep getting the error Segmentation Fault: 11. The goal is to make dark circles on a picture of a boarder, ect with command. My reasoning that it isn't working if because of my File IO. I did it without the in & out FILE types and changed the two functions that are called in pgmUtility to not call in files and the program ran smoothly. So I'm assuming I need to have help focusing on the issues I have with my file IO.
Command used:
$ ./a.out -c 470 355 100 < balloons.ascii.pgm > TestImages/balloons_c100_4.pgm
It uses main.c program that relates to pgmUtility.c
This is Main.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include "pgmUtility.h"
#define ROWS 4
#define COLS 100
void usage(void)
{
printf("Usage\n");
printf(" -h Help Dialog\n");
printf(" -e edgeWidth < OldImageFile > NewImageFile\n");
printf(" -c centerRow centerCol radius < OldImageFile > NewImageFile\n");
printf(" -e edgeWidth -c radius centerRow centerCol < OldImageFile > NewImageFile\n");
exit (8);
}
int main(int argc, char * argv[]) {
FILE *fp;
FILE *out;
int i, j;
int flag1 = 0; //-e switch (edge draw)
int flag2 = 0; //-c switch (circle draw)
int numRows, numCols, centerRow, centerCol, radius, edgeWidth;
char originalImage[100], newImageFile[100];
char **header = (char**) malloc (sizeof(char*)*4);
int **pixels;
//command line argument parsing
//turn flag switches on or off
if(argc < 3)
usage();
if(argc > 7)
usage();
for(i = 1; i < argc; i++) {
if(strncmp(argv[i], "-e", 2) == 0) {
//set flag on
//get edge with values)
if(atoi(argv[i+1]) == 0) {
usage();
}
edgeWidth = atoi(argv[i+1]);
if(argv[i+2] != NULL) {
if(atoi(argv[i+2]) != 0) {
usage();
}
}
flag1 = 1;
}
if(strncmp(argv[i], "-c", 2) == 0) {
//set flag on
//get radius and center values
if(atoi(argv[i+1]) == 0) {
usage();
}
centerRow = atoi(argv[i+1]);
centerCol = atoi(argv[i+2]);
radius = atoi(argv[i+3]);
flag2 = 1;
strcpy(originalImage, argv[5]);
strcpy(newImageFile, argv[6]);
fp = fopen(originalImage, "r");
out = fopen(newImageFile, "w");
}
if(strncmp(argv[i], "-h", 2) == 0) {
usage();
}
}
//allocate memory for header array
header = (char **)malloc(ROWS * sizeof(char));
for(i = 0; i < ROWS; i++) {
for(j = 0; j < COLS; j++) {
header[i] = (char *)malloc(COLS * sizeof(char *));
}
}
//read pgm file
pixels = pgmRead(header, &numRows, &numCols, fp);
if(pixels == NULL)
usage();
switch(flag1) {
case 1 :
if(flag2 == 1) {
//execute circle draw and edge draw
pgmDrawCircle(pixels, numRows, numCols, centerRow, centerCol, radius, header);
pgmDrawEdge(pixels, numRows, numCols, edgeWidth, header);
}
else {
//execute only edge draw only
pgmDrawEdge(pixels, numRows, numCols, edgeWidth, header);
}
break;
case 0 :
if(flag2 == 1) {
//execute circle draw
pgmDrawCircle(pixels, numRows, numCols, centerRow, centerCol, radius, header);
}
break;
default :
usage();
break;
}
//write new pgm file
pgmWrite((const char **)header, (const int **)pixels, numRows, numCols, out);
//Garbage Collection
//Fix this
//free(pixels);
//free(header);
for(i = 0; i < numRows; i++) {
int *current= pixels[i];
free(current);
}
for(i = 0; i < ROWS; i++) {
char *current = header[i];
free(current);
}
return 0;
}
This is two functions from pgmUtility.c that I think may be the cause of the issue.
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include "pgmUtility.h"
#define ROWS 4
#define COLS 100
// Implement or define each function prototypes listed in pgmUtility.h file.
// NOTE: You can NOT change the input, output, and argument type of the functions in pgmUtility.h
// NOTE: You can NOT change the prototype (signature) of any functions listed in pgmUtility.h
int ** pgmRead( char **header, int *numRows, int *numCols, FILE *in ){
int r, c;
int **array;
for(r = 0; r < ROWS; r++) {
fgets(header[r], COLS, stdin);
if(header == NULL)
return NULL;
}
//sscanf parses the numRows and numCols
sscanf(header[ROWS - 2], "%d %d", numCols, numRows);
//read in pixel map
array = (int **)malloc(*numRows * sizeof(int *));
for(r = 0; r < *numRows; r++) {
array[r] = (int *)malloc(*numCols * sizeof(int));
}
for(r = 0; r < *numRows; r++) {
for(c = 0; c < *numCols; c++) {
fscanf(in, "%d", *(array + r) + c );
}
}
fclose(in);
return array;
}
int pgmWrite( const char **header, const int **pixels, int numRows, int numCols, FILE *out ){
//iterate straight through pixels
//setup with a loop to insert a new line every "numCols" and keep printing until "numRows + 1" is reached (as soon as numRows + 1 break loop)
int i, j;
for(i = 0; i < 4; i++){
//printf("%s", *header[i]);
fprintf(out, "%c", *header[i]);
}
//for(i = 0; i < 4; i++)
//fprintf(out, "*I=%d**%s**", i, header[i]);
for(j = 0; j < numRows; j++){
for(i = 0; i < numCols; i++)
fprintf(out, "%d ", pixels[i][j]);
fprintf(out, "\n");
}
fclose(out);
return 0;
}

Answer 1

You're not allocating the header arrays correctly. It should be:
header = malloc(ROWS * sizeof(char*));
for(i = 0; i < ROWS; i++) {
header[i] = malloc(COLS * sizeof(char));
}
You had the wrong types in the two sizeof calls.
You didn't need the inner j loop at all, you were repeatedly assigning to the same header[i].
And for C (but not C++) see: Do I cast the result of malloc?
Also, at the beginning of main() you have an extra allocation that you never use or free:
char **header = (char**) malloc (sizeof(char*)*4);
You should get rid of this.
It's not related to the error, but this is wrong:
if(header == NULL)
return NULL;
You should be testing header[r].
For clarity, I recommend rewriting:
fscanf(in, "%d", *(array + r) + c );
as:
fscanf(in, "%d", &array[r][c]);

Answer 2

It appears (even after correcting the malloc call as correctly suggested), you are allocating header[i] COLS number of times.
header = malloc(ROWS * sizeof(char*));
for(i = 0; i < ROWS; i++) {
for(j = 0; j < COLS; j++) {
header[i] = malloc(COLS * sizeof(char)); // this happens COLS times
}
}
That will leave COLS number of each header[i] allocated. As I read your code, you need only allocate a single char array for each header[i]. To do this, you need to move header[i] = malloc(COLS * sizeof(char)); outside the for(j = 0; j < COLS; j++) loop:
header = malloc(ROWS * sizeof(char*));
for(i = 0; i < ROWS; i++) {
header[i] = malloc(COLS * sizeof(char));
}
You should also validate that header and each header[i] were successfully allocated.