Add a "fork" of musl as //fusl.

fusl/include/stdio.h

+#ifndef _STDIO_H
+#define _STDIO_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <features.h>
+
+#define __NEED_FILE
+#define __NEED___isoc_va_list
+#define __NEED_size_t
+
+#if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
+ || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) \
+ || defined(_BSD_SOURCE)
+#define __NEED_ssize_t
+#define __NEED_off_t
+#define __NEED_va_list
+#endif
+
+#include <bits/alltypes.h>
+
+#ifdef __cplusplus
+#define NULL 0L
+#else
+#define NULL ((void*)0)
+#endif
+
+#undef EOF
+#define EOF (-1)
+
+#undef SEEK_SET
+#undef SEEK_CUR
+#undef SEEK_END
+#define SEEK_SET 0
+#define SEEK_CUR 1
+#define SEEK_END 2
+
+#define _IOFBF 0
+#define _IOLBF 1
+#define _IONBF 2
+
+#define BUFSIZ 1024
+#define FILENAME_MAX 4096
+#define FOPEN_MAX 1000
+#define TMP_MAX 10000
+#define L_tmpnam 20
+
+typedef union _G_fpos64_t {
+        char __opaque[16];
+        double __align;
+} fpos_t;
+
+extern FILE *const stdin;
+extern FILE *const stdout;
+extern FILE *const stderr;
+
+#define stdin  (stdin)
+#define stdout (stdout)
+#define stderr (stderr)
+
+FILE *fopen(const char *__restrict, const char *__restrict);
+FILE *freopen(const char *__restrict, const char *__restrict, FILE *__restrict);
+int fclose(FILE *);
+
+int remove(const char *);
+int rename(const char *, const char *);
+
+int feof(FILE *);
+int ferror(FILE *);
+int fflush(FILE *);
+void clearerr(FILE *);
+
+int fseek(FILE *, long, int);
+long ftell(FILE *);
+void rewind(FILE *);
+
+int fgetpos(FILE *__restrict, fpos_t *__restrict);
+int fsetpos(FILE *, const fpos_t *);
+
+size_t fread(void *__restrict, size_t, size_t, FILE *__restrict);
+size_t fwrite(const void *__restrict, size_t, size_t, FILE *__restrict);
+
+int fgetc(FILE *);
+int getc(FILE *);
+int getchar(void);
+int ungetc(int, FILE *);
+
+int fputc(int, FILE *);
+int putc(int, FILE *);
+int putchar(int);
+
+char *fgets(char *__restrict, int, FILE *__restrict);
+#if __STDC_VERSION__ < 201112L
+char *gets(char *);
+#endif
+
+int fputs(const char *__restrict, FILE *__restrict);
+int puts(const char *);
+
+int printf(const char *__restrict, ...);
+int fprintf(FILE *__restrict, const char *__restrict, ...);
+int sprintf(char *__restrict, const char *__restrict, ...);
+int snprintf(char *__restrict, size_t, const char *__restrict, ...);
+
+int vprintf(const char *__restrict, __isoc_va_list);
+int vfprintf(FILE *__restrict, const char *__restrict, __isoc_va_list);
+int vsprintf(char *__restrict, const char *__restrict, __isoc_va_list);
+int vsnprintf(char *__restrict, size_t, const char *__restrict, __isoc_va_list);
+
+int scanf(const char *__restrict, ...);
+int fscanf(FILE *__restrict, const char *__restrict, ...);
+int sscanf(const char *__restrict, const char *__restrict, ...);
+int vscanf(const char *__restrict, __isoc_va_list);
+int vfscanf(FILE *__restrict, const char *__restrict, __isoc_va_list);
+int vsscanf(const char *__restrict, const char *__restrict, __isoc_va_list);
+
+void perror(const char *);
+
+int setvbuf(FILE *__restrict, char *__restrict, int, size_t);
+void setbuf(FILE *__restrict, char *__restrict);
+
+char *tmpnam(char *);
+FILE *tmpfile(void);
+
+#if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
+ || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) \
+ || defined(_BSD_SOURCE)
+FILE *fmemopen(void *__restrict, size_t, const char *__restrict);
+FILE *open_memstream(char **, size_t *);
+FILE *fdopen(int, const char *);
+FILE *popen(const char *, const char *);
+int pclose(FILE *);
+int fileno(FILE *);
+int fseeko(FILE *, off_t, int);
+off_t ftello(FILE *);
+int dprintf(int, const char *__restrict, ...);
+int vdprintf(int, const char *__restrict, __isoc_va_list);
+void flockfile(FILE *);
+int ftrylockfile(FILE *);
+void funlockfile(FILE *);
+int getc_unlocked(FILE *);
+int getchar_unlocked(void);
+int putc_unlocked(int, FILE *);
+int putchar_unlocked(int);
+ssize_t getdelim(char **__restrict, size_t *__restrict, int, FILE *__restrict);
+ssize_t getline(char **__restrict, size_t *__restrict, FILE *__restrict);
+int renameat(int, const char *, int, const char *);
+char *ctermid(char *);
+#define L_ctermid 20
+#endif
+
+
+#if defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) \
+ || defined(_BSD_SOURCE)
+#define P_tmpdir "/tmp"
+char *tempnam(const char *, const char *);
+#endif
+
+#if defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
+#define L_cuserid 20
+char *cuserid(char *);
+void setlinebuf(FILE *);
+void setbuffer(FILE *, char *, size_t);
+int fgetc_unlocked(FILE *);
+int fputc_unlocked(int, FILE *);
+int fflush_unlocked(FILE *);
+size_t fread_unlocked(void *, size_t, size_t, FILE *);
+size_t fwrite_unlocked(const void *, size_t, size_t, FILE *);
+void clearerr_unlocked(FILE *);
+int feof_unlocked(FILE *);
+int ferror_unlocked(FILE *);
+int fileno_unlocked(FILE *);
+int getw(FILE *);
+int putw(int, FILE *);
+char *fgetln(FILE *, size_t *);
+int asprintf(char **, const char *, ...);
+int vasprintf(char **, const char *, __isoc_va_list);
+#endif
+
+#ifdef _GNU_SOURCE
+char *fgets_unlocked(char *, int, FILE *);
+int fputs_unlocked(const char *, FILE *);
+#endif
+
+#if defined(_LARGEFILE64_SOURCE) || defined(_GNU_SOURCE)
+#define tmpfile64 tmpfile
+#define fopen64 fopen
+#define freopen64 freopen
+#define fseeko64 fseeko
+#define ftello64 ftello
+#define fgetpos64 fgetpos
+#define fsetpos64 fsetpos
+#define fpos64_t fpos_t
+#define off64_t off_t
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif