Reading a file in C on Linux - c

Question

How do I read a file into a string on Linux in C?
I came up with some code, but it's not working, and idk why. fgetc() always returns -1.
The file structure is something like this
.:
Files/
main.c
makefile
./Files:
test
Contents of main.c:
#include <stdio.h>
int fileLength(const char filePath[]);
void readFile(const char filePath[], char* outString);
int main()
{
char fileContents[fileLength("Files/test")];
readFile("Files/test", &fileContents);
printf("DEBUG: Address of fileContents is 0x%x\n", &fileContents);
printf("File contents:\n%s\n", fileContents);
return 0;
}
int fileLength(const char filePath[])
{
//Open the file
FILE* file;
if ((file = fopen(filePath, "r")) == NULL)
{
printf("ERROR: File (%s) cannot be opened.\n", filePath);
return -1;
}
//Find the length
fseek(file, 0, SEEK_END);
return ftell(file);
}
void readFile(const char filePath[], char* outString)
{
FILE* file;
//File reading
printf("DEBUG: File path is %s\n", filePath);
if ((file = fopen(filePath, "r")) == NULL)
{
printf("ERROR: File (%s) cannot be opened.\n", filePath);
exit(1);
}
//Get length of file and allocate the according amount of memory
fseek(file, 0, SEEK_END);
int fileLength = ftell(file);
printf("DEBUG: File length is %i\n", fileLength);
//Allocate string
char fileContent[fileLength];
//Read file to string
printf("DEBUG: File contents as digits:\n");
for (int i = 0; i < fileLength; i++)
{
fileContent[i] = fgetc(file);
printf("%d ", fileContent[i]);
}
printf("\n");
printf("DEBUG: Contents of file are:\n%s\n", fileContent);
fclose(file);
printf("DEBUG: outString is pointing to 0x%x\n", outString);
*outString = fileContent;
}
The output is usually just a bunch of question mark diamond things (running in terminal) that match the length of the file with a few other random chars thrown in at the end. The chars at the end change every time the program is run.

Answer 1

kaylum was right, the solution was to:
rewind() after finding the file length in readFile()
remember to fclose() when done
write directly to outString instead of using fileContent
The final code of main.c comes out to be:
#include <stdio.h>
int fileLength(const char filePath[]);
void readFile(const char filePath[], char* outString);
int main()
{
char fileContents[fileLength("Files/test")];
readFile("Files/test", &fileContents);
printf("File contents:\n%s\n", fileContents);
return 0;
}
int fileLength(const char filePath[])
{
//Open the file
FILE* file;
if ((file = fopen(filePath, "r")) == NULL)
{
printf("ERROR: File (%s) cannot be opened.\n", filePath);
return -1;
}
//Find the length
fseek(file, 0, SEEK_END);
int length = ftell(file);
fclose(file);
return length;
}
void readFile(const char filePath[], char* outString)
{
FILE* file;
//File reading
if ((file = fopen(filePath, "r")) == NULL)
{
printf("ERROR: File (%s) cannot be opened.\n", filePath);
exit(1);
}
//Get length of file and allocate the according amount of memory
fseek(file, 0, SEEK_END);
int fileLength = ftell(file);
rewind(file);
//Read file to string
for (int i = 0; i < fileLength; i++)
outString[i] = fgetc(file);
fclose(file);
}