diff --git a/include/tlibc/errors.h b/include/tlibc/errors.h
index 1928157..2b001a2 100755
--- a/include/tlibc/errors.h
+++ b/include/tlibc/errors.h
@@ -41,7 +41,8 @@ typedef struct Result_ {
 
 
 #define RESULT_ERROR(MSG, IS_MSG_ON_HEAP) (Result_){ .error = Error_create(MSG, IS_MSG_ON_HEAP, ErrorCallPos_here()) }
-#define RESULT_ERROR_FMT(FORMAT, ARGS...) RESULT_ERROR(sprintf_malloc(4096, FORMAT, ARGS), true)
+#define RESULT_ERROR_FMT(FORMAT, ARGS...) RESULT_ERROR(sprintf_malloc(4096, FORMAT ,##ARGS), true)
+#define RESULT_ERROR_ERRNO() RESULT_ERROR(strerror(errno), false)
 #define RESULT_VOID (Result_){ .error = NULL }
 #define RESULT_VALUE(FIELD, V) (Result_){ .error = NULL, .FIELD = V }
 
diff --git a/include/tlibc/filesystem.h b/include/tlibc/filesystem.h
index 3996000..21eb88b 100644
--- a/include/tlibc/filesystem.h
+++ b/include/tlibc/filesystem.h
@@ -1,17 +1,24 @@
 #pragma once
+#include <stdio.h>
 #include "std.h"
 #include "errors.h"
 #include "string/str.h"
+#include "collections/Array.h"
 
-#if !defined(KFS_USE_WINDOWS_H)
+#if !defined(TLIBC_FS_USE_WINDOWS_H)
     #if defined(_WIN64) || defined(_WIN32)
-        #define KFS_USE_WINDOWS_H 1
+        #define TLIBC_FS_USE_WINDOWS_H 1
     #else 
-        #define KFS_USE_WINDOWS_H 0
+        #define TLIBC_FS_USE_WINDOWS_H 0
     #endif
 #endif
 
-#if KFS_USE_WINDOWS_H
+
+//////////////////////////////////////////////////////////////////////////////
+//                                   PATH                                   //
+//////////////////////////////////////////////////////////////////////////////
+
+#if defined(_WIN64) || defined(_WIN32)
     #define path_sep '\\'
     #define path_seps "\\"
     #define path_notsep '/'
@@ -32,6 +39,10 @@ str path_dirname(str path);
 str path_basename(str path, bool remove_ext);
 
 
+//////////////////////////////////////////////////////////////////////////////
+//                                   FILE                                   //
+//////////////////////////////////////////////////////////////////////////////
+
 /// open a file for reading 
 #define FO_Read "rb"
 /// (re)create a file for writing
@@ -45,10 +56,11 @@ str path_basename(str path, bool remove_ext);
 
 Result(FILE*) file_open(cstr file_name, cstr fopen_mode);
 
-bool file_exists(cstr path);
 
+bool file_exists(cstr path);
 Result(i64) file_getSize(FILE* f);
 
+
 typedef enum SeekOrigin {
     SeekOrigin_Start = SEEK_SET,
     SeekOrigin_Current = SEEK_CUR,
@@ -58,6 +70,58 @@ typedef enum SeekOrigin {
 Result(void) file_seek(FILE* f, i64 offset, SeekOrigin origin);
 
 
+Result(void) file_writeByte(FILE* f, u8 b);
+Result(void) file_writeStructs(FILE* f, const void* src, u64 struct_size, u64 count);
+
+static inline Result(void) file_writeBytes(FILE* f, const void* src, u64 size){
+    return file_writeStructs(f, src, size, 1);
+}
+
+static inline Result(void) file_writeBytesArray(FILE* f, Array(u8) src){
+    return file_writeStructs(f, src.data, src.size, 1);
+}
+
+
+/// @param out_byte is not set on error or end of file
+/// @return true if byte was read, false if end of file was reached
+Result(bool) file_readByte(FILE* f, u8* out_byte);
+
+
+/// @param max_count maximum number of structs to read
+/// @return number of structs that were read (<=max_count)
+Result(u64) file_readStructs(FILE* f, void* dst, u64 struct_size, u64 max_count);
+
+/// @param max_count maximum number of bytes to read
+/// @return number of bytes that were read (<=max_count)
+static inline Result(u64) file_readBytes(FILE* f, void* dst, u64 max_count){
+    return file_readStructs(f, dst, 1, max_count);
+}
+
+/// @param dst array where .size is the maximum number of bytes to read
+/// @return number of bytes that were read (<=max_count)
+static inline Result(u64) file_readBytesArray(FILE* f, Array(u8) dst){
+    return file_readStructs(f, dst.data, 1, dst.size);
+}
+
+
+/// @param max_count exact number of structs to read
+Result(void) file_readStructsExactly(FILE* f, void* dst, u64 struct_size, u64 exact_count);
+
+/// @param exact_count exact number of bytes to read
+static inline Result(void) file_readBytesExactly(FILE* f, void* dst, u64 exact_count){
+    return file_readStructsExactly(f, dst, 1, exact_count);
+}
+
+/// @param dst array where .size is the exact number of bytes to read
+static inline Result(void) file_readBytesArrayExactly(FILE* f, Array(u8) dst){
+    return file_readStructsExactly(f, dst.data, 1, dst.size);
+}
+
+//////////////////////////////////////////////////////////////////////////////
+//                                DIRECTORY                                 //
+//////////////////////////////////////////////////////////////////////////////
+
 bool dir_exists(cstr path);
 
+/// @brief creates directories specified in path recursively if they don't exist 
 Result(void) dir_create(cstr path);
diff --git a/src/filesystem/dir.c b/src/filesystem/dir.c
index 73ad5e1..8eb0b10 100644
--- a/src/filesystem/dir.c
+++ b/src/filesystem/dir.c
@@ -1,5 +1,5 @@
 #include "tlibc/filesystem.h"
-#include "io_includes.h"
+#include "internal.h"
 
 bool dir_exists(cstr path){
     if(path[0]=='.'){
@@ -8,7 +8,7 @@ bool dir_exists(cstr path){
         // else if(path[1]=='.' && path[2]==path_sep)
         //TODO path_resolve because windows doesnt recognize .\ pattern
     }
-#if KFS_USE_WINDOWS_H
+#if TLIBC_FS_USE_WINDOWS_H
     DWORD dwAttrib = GetFileAttributes(path);
     return (bool)(
         (dwAttrib != INVALID_FILE_ATTRIBUTES) && // file exists
@@ -29,7 +29,7 @@ Result(void) dir_create(cstr path){
     char* parentDir= str_copy(path_dirname(str_from_cstr((void*)path))).data;
     try_void(dir_create(parentDir), free(parentDir));
     free(parentDir);
-#if KFS_USE_WINDOWS_H
+#if TLIBC_FS_USE_WINDOWS_H
     if(!CreateDirectory(path, NULL))
 #else
     if(mkdir(path, 0777) == -1)
diff --git a/src/filesystem/file.c b/src/filesystem/file.c
index 7d7f5e4..313de5a 100644
--- a/src/filesystem/file.c
+++ b/src/filesystem/file.c
@@ -1,5 +1,5 @@
 #include "tlibc/filesystem.h"
-#include "io_includes.h"
+#include "internal.h"
 
 bool file_exists(cstr path){
     if(path[0]=='.'){
@@ -9,7 +9,7 @@ bool file_exists(cstr path){
         //TODO path_resolve because windows doesnt recognize .\ pattern
     }
 
-#if KFS_USE_WINDOWS_H
+#if TLIBC_FS_USE_WINDOWS_H
     DWORD dwAttrib = GetFileAttributes(path);
     return (bool)(
         (dwAttrib != INVALID_FILE_ATTRIBUTES) && // file exists
@@ -35,7 +35,7 @@ Result(FILE*) file_open(cstr file_name, cstr fopen_mode){
 Result(i64) file_getSize(FILE* f){
     i64 r = IFWIN(_ftelli64, ftello64)(f);
     if(r < 0){
-        return RESULT_ERROR(strerror(errno), false);
+        return RESULT_ERROR_ERRNO();
     }
     return RESULT_VALUE(i, r);
 }
@@ -47,4 +47,53 @@ Result(void) file_seek(FILE* f, i64 offset, SeekOrigin origin){
             offset, origin, strerror(errno));
     }
     return RESULT_VOID;
-}
\ No newline at end of file
+}
+
+
+Result(void) file_writeStructs(FILE* f, const void* src, u64 struct_size, u64 count){
+    u64 r = fwrite(src, struct_size, count, f);
+    if(r != count){
+        return RESULT_ERROR_ERRNO();
+    }
+    return RESULT_VOID;
+}
+
+Result(void) file_writeByte(FILE* f, u8 b){
+    if(fputc(b, f) != 0){
+        return RESULT_ERROR_ERRNO();
+    }
+    return RESULT_VOID;
+}
+
+Result(bool) file_readByte(FILE* f, u8* out_byte){
+    int r = fgetc(f);
+    if(ferror(f)){
+        return RESULT_ERROR_ERRNO();
+    }
+    if(feof(f)){
+        return RESULT_VALUE(u, false);
+    }
+    *out_byte = r;
+    return RESULT_VALUE(u, true);
+}
+
+Result(u64) file_readStructs(FILE* f, void* dst, u64 struct_size, u64 max_count){
+    u64 r = fread(dst, struct_size, max_count, f);
+    if(ferror(f)){
+        return RESULT_ERROR_ERRNO();
+    }
+    return RESULT_VALUE(u, r);
+}
+
+Result(void) file_readStructsExactly(FILE* f, void* dst, u64 struct_size, u64 exact_count){
+    u64 r = fread(dst, struct_size, exact_count, f);
+    if(ferror(f)){
+        return RESULT_ERROR_ERRNO();
+    }
+    if(r != exact_count){
+        return RESULT_ERROR_FMT(
+            "read " IFWIN("%llu", "%lu") " structures out of " IFWIN("%llu", "%lu"),
+            r, exact_count);
+    }
+    return RESULT_VOID;
+}
diff --git a/src/filesystem/io_includes.h b/src/filesystem/internal.h
similarity index 66%
rename from src/filesystem/io_includes.h
rename to src/filesystem/internal.h
index 2b75fc8..4addc95 100644
--- a/src/filesystem/io_includes.h
+++ b/src/filesystem/internal.h
@@ -1,6 +1,7 @@
 #pragma once
 
-#if KFS_USE_WINDOWS_H
+#include "tlibc/filesystem.h"
+#if TLIBC_FS_USE_WINDOWS_H
 #include <windows.h>
 #else
 #include <sys/types.h>