pretty sure esc here is just a holdover from past, and has no use in rearranged implementation.
#pragma once
#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>
#include <wchar.h>
typedef union string255_
{
struct {
char s[256];
};
struct {
char len;
char str[255];
};
} string255;
typedef struct string192_
{
char s[193];
} string192;
typedef struct string31_
{
char s[32];
} string31;
typedef struct string15_
{
char s[16];
} string15;
typedef string255 shortstring;
typedef string255 ansistring;
typedef uint8_t Byte;
typedef int8_t ShortInt;
typedef uint16_t Word;
typedef int16_t SmallInt;
typedef uint32_t LongWord;
typedef int32_t LongInt;
typedef uint64_t QWord;
typedef int64_t Int64;
typedef LongWord Cardinal;
typedef LongInt Integer;
typedef float extended;
typedef float real;
typedef float single;
typedef bool boolean;
typedef int LongBool;
typedef void * pointer;
typedef Byte * PByte;
typedef char * PChar;
typedef LongInt * PLongInt;
typedef LongWord * PLongWord;
typedef Integer * PInteger;
typedef int PtrInt;
typedef wchar_t widechar;
#define new(a) __new((void **)&a, sizeof(*(a)))
void __new(void ** p, int size);
#define dispose(a) __dispose(a, sizeof(*(a)))
void __dispose(pointer p, int size);
void * GetMem(int size);
void FreeMem(void * p, int size);
#define FillChar(a, b, c) __FillChar(&(a), b, c)
void __FillChar(pointer p, int size, char fill);
string255 _strconcat(string255 a, string255 b);
string255 _strappend(string255 s, char c);
string255 _strprepend(char c, string255 s);
string255 _chrconcat(char a, char b);
bool _strcompare(string255 a, string255 b);
bool _strcomparec(string255 a, char b);
bool _strncompare(string255 a, string255 b);
char * _pchar(string255 s);
string255 pchar2str(char * s);
int Length(string255 a);
string255 copy(string255 a, int s, int l);
string255 delete(string255 a, int s, int l);
string255 trim(string255 a);
#define STRINIT(a) {.len = sizeof(a) - 1, .str = a}
int length_ar(void * a);
typedef int file;
typedef int TextFile;
extern int FileMode;
extern int IOResult;
extern int stdout;
extern int stderr;
#define assign(a, b) assign_(&(a), b)
void assign_(int * f, string255 fileName);
void reset_1(int f, int size);
void reset_2(int f, int size);
#define BlockRead(a, b, c, d) BlockRead_(a, &(b), c, &(d))
void BlockRead_(int f, void * p, int size, int * sizeRead);
#define BlockWrite(a, b, c) BlockWrite_(a, &(b), c)
void BlockWrite_(int f, void * p, int size);
void close(int f);
void write(int f, string255 s);
void writeLn(int f, string255 s);
bool DirectoryExists(string255 dir);
bool FileExists(string255 filename);
bool odd(int i);
typedef int TThreadId;
void ThreadSwitch();
#define InterlockedIncrement(a) __InterlockedIncrement(&(a))
#define InterlockedDecrement(a) __InterlockedDecrement(&(a))
void __InterlockedIncrement(int * a);
void __InterlockedDecrement(int * a);
bool Assigned(void * a);
void randomize();
int random(int max);
int abs(int i);
double sqr(double n);
double sqrt(double n);
int trunc(double n);
int round(double n);
string255 ParamStr(int n);
int ParamCount();
#define val(a, b, c) _val(a, (LongInt*)&(b), (LongInt*)&(c))
void _val(string255 str, LongInt * a, LongInt * c);
extern double pi;
string255 EnumToStr(int a);
string255 ExtractFileName(string255 f);