file parsing

I don't think this is finished yet but it's late and not on my pc so I
have to upload it now...

fisualizer.c

@@ -1,15 +1,22 @@
 #include <stdlib.h>
 #include <stdio.h>
+#define STB_IMAGE_WRITE_IMPLEMENTATION
+#include "stb_image_write.h"
+#include <string.h>
 
 FILE *fd;
 size_t file_sz;
-char* file_cnt;
+unsigned char *file_cnt, *canvas;
+char *filename_output;
 
 int main(int argc, char *argv[])
 {
+	argv++;
 	while(argc--){
 
 		const char* filename = *argv++;
+		filename_output = malloc(sizeof(char) * strlen(filename) + 8);
+		strcpy(filename_output, filename);
 		fd = fopen(filename, "r");
 		if(fd == NULL){
 			fprintf(stderr, "couldn't open this file: %s\n", filename);
@@ -24,9 +31,18 @@ int main(int argc, char *argv[])
 		file_cnt = malloc(sizeof(char)*file_sz);
 		fread(file_cnt, sizeof(char), file_sz, fd);
 
-		printf("%s\n", file_cnt);
+		canvas = calloc(256*256, sizeof(char));
 
+		for (size_t i = 0; i < file_sz - 1; ++i) {
+			unsigned char at_pos = file_cnt[i], next_pos = file_cnt[i+1];
+			canvas[at_pos + next_pos * 256] = 255;
+		}
+
+		stbi_write_png(strcat(filename_output, ".out.png"), 256, 256, 1, canvas, 256);
+
+		free(canvas);
 		free(file_cnt);
+		free(filename_output);
 		fclose(fd);
 	}
 	return 0;