将文件的全部内容读取到 c char *，包括新行

#include<stdio.h>
#include <stdlib.h>
#include<string.h>

char *read_file(const char *filename) {
    FILE *file = fopen(filename, "rb");
    if (file == NULL) {
        return NULL;
    }

    fseek(file, 0, SEEK_END);
    long size = ftell(file);
    fseek(file, 0, SEEK_SET);

    char *buffer = (char *)malloc(size + 1);
    if (buffer == NULL) {
        fclose(file);
        return NULL;
    }

    fread(buffer, 1, size, file);
    buffer[size] = '\0';

    fclose(file);

    return buffer;
}

int main() {
    char *content = read_file("example.txt");
    if (content != NULL) {
        printf("%s", content);
        free(content);
    }

    return 0;
}