Add epoll and do more release readiness changes

This change also pays off some of the remaining technical debt with
stdio, file descriptors, and memory managemnt polyfills.

libc/stdio/favail.c

@@ -19,6 +19,8 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/stdio/stdio.h"
 
+/* TODO(jart): Delete or rework */
+
 /**
  * Returns number of bytes available in stream buffer.
  */

libc/stdio/fclose.c

@@ -37,10 +37,12 @@
  */
 int fclose(FILE *f) {
   int rc;
-  if (!f) return 0; /* good java behavior; glibc crashes */
+  if (!f) return 0;
   _fflushunregister(f);
   fflush(f);
-  free_s(&f->buf);
+  if (!f->nofree) {
+    free_s(&f->buf);
+  }
   f->state = EOF;
   if (f->noclose) {
     f->fd = -1;

libc/stdio/fdopen.c

@@ -17,6 +17,8 @@
 │ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA                │
 │ 02110-1301 USA                                                               │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/calls/calls.h"
+#include "libc/mem/mem.h"
 #include "libc/stdio/internal.h"
 #include "libc/stdio/stdio.h"
 #include "libc/sysv/consts/o.h"
@@ -31,14 +33,21 @@
  * @error ENOMEM
  */
 FILE *fdopen(int fd, const char *mode) {
-  FILE *res;
-  if ((res = fmemopen(NULL, BUFSIZ, mode))) {
-    res->fd = fd;
-    res->reader = freadbuf;
-    res->writer = fwritebuf;
-    if ((res->iomode & O_ACCMODE) != O_RDONLY) {
-      _fflushregister(res);
+  FILE *f;
+  if ((f = calloc(1, sizeof(FILE)))) {
+    f->fd = fd;
+    f->reader = __freadbuf;
+    f->writer = __fwritebuf;
+    f->bufmode = ischardev(fd) ? _IOLBF : _IOFBF;
+    f->iomode = fopenflags(mode);
+    f->size = BUFSIZ;
+    if ((f->buf = valloc(f->size))) {
+      if ((f->iomode & O_ACCMODE) != O_RDONLY) {
+        _fflushregister(f);
+      }
+      return f;
     }
+    free(f);
   }
-  return res;
+  return NULL;
 }

libc/stdio/feof.c

@@ -19,6 +19,9 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/stdio/stdio.h"
 
+/**
+ * Returns true if stream is in end-of-file state.
+ */
 int feof(FILE *f) {
   return f->state == -1;
 }

libc/stdio/fflush.c

@@ -45,7 +45,6 @@ static struct StdioFlush g_fflush;
  *
  * @param f is the stream handle
  * @return number of bytes written or -1 on error
- * @see fwritebuf
  */
 int fflush(FILE *f) {
   size_t i;
@@ -62,19 +61,14 @@ int fflush(FILE *f) {
         }
       }
     }
-  } else if (f->fd != -1 && (f->iomode & O_WRONLY)) {
-    if (!f->state) {
-      while (f->beg != f->end) {
-        if ((wrote = fwritebuf(f)) != -1) {
-          res += wrote;
-        } else {
-          res = -1;
-          break;
-        }
+  } else if (f->fd != -1) {
+    while (!f->state && f->beg && !f->end) {
+      if ((wrote = __fwritebuf(f)) != -1) {
+        res += wrote;
       }
-    } else if (f->state != -1) {
-      res = fseterr(f, f->state);
     }
+  } else if (f->beg && f->beg < f->size) {
+    f->buf[f->beg] = 0;
   }
   return res;
 }

libc/stdio/fgetc.c

@@ -17,11 +17,17 @@
 │ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA                │
 │ 02110-1301 USA                                                               │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/stdio/internal.h"
 #include "libc/stdio/stdio.h"
 
 /**
  * Reads uint8_t from stream.
  */
 int fgetc(FILE *f) {
-  return getc(f);
+  int c;
+  if (f->beg >= f->end) {
+    if (!f->reader) return __fseteof(f);
+    if (f->reader(f) == -1) return -1;
+  }
+  return f->buf[f->beg++];
 }

libc/stdio/fmemopen.c

@@ -17,12 +17,8 @@
 │ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA                │
 │ 02110-1301 USA                                                               │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/bits/bits.h"
 #include "libc/bits/popcnt.h"
-#include "libc/calls/calls.h"
-#include "libc/errno.h"
 #include "libc/mem/mem.h"
-#include "libc/runtime/runtime.h"
 #include "libc/stdio/stdio.h"
 #include "libc/str/str.h"
 #include "libc/sysv/consts/o.h"
@@ -31,46 +27,46 @@
 /**
  * Opens buffer as stream.
  *
- * This function is the heart of the streams implementation, and it's
- * truly magnificent for unit testing.
- *
  * @param buf becomes owned by this function, and is allocated if NULL
  * @return new stream or NULL w/ errno
- * @error ENOMEM, EINVAL
  */
 FILE *fmemopen(void *buf, size_t size, const char *mode) {
-  FILE *res;
+  FILE *f;
+  char *p;
   unsigned flags;
 
-  if (buf && !size) {
+  if (size && size > 0x7ffff000) {
     einval();
     return NULL;
   }
 
-  if (size && popcnt(size) != 1) {
-    einval();
-    return NULL;
-  }
-
-  if (!(res = calloc(1, sizeof(FILE)))) {
+  if (!(f = calloc(1, sizeof(FILE)))) {
     return NULL;
   }
 
   if (!buf) {
-    if (!size) size = FRAMESIZE;
-    if (!(buf = valloc(size))) {
-      free(res);
+    if (!size) size = BUFSIZ;
+    if (!(buf = calloc(1, size))) {
+      free(f);
       return NULL;
     }
+  } else {
+    f->nofree = true;
+  }
+
+  f->fd = -1;
+  f->buf = buf;
+  f->size = size;
+  f->end = size;
+  f->iomode = fopenflags(mode);
+
+  if (f->iomode & O_APPEND) {
+    if ((p = memchr(buf, '\0', size))) {
+      f->beg = p - (char *)buf;
+    } else {
+      f->beg = f->end;
+    }
   }
 
-  res->fd = -1;
-  setbuffer(res, buf, size);
-  res->bufmode = res->buf ? _IOFBF : _IONBF;
-  flags = fopenflags(mode);
-  res->iomode = (flags & O_ACCMODE) == O_RDWR
-                    ? O_RDWR
-                    : (flags & O_ACCMODE) == O_WRONLY ? O_WRONLY : O_RDONLY;
-
-  return res;
+  return f;
 }

libc/stdio/fputc.c

@@ -27,20 +27,19 @@
  * @return c (as unsigned char) if written or -1 w/ errno
  */
 noinstrument int fputc(int c, FILE *f) {
-  if (c != -1) {
+  if (f->beg < f->size) {
     c &= 0xff;
-    f->buf[f->end] = c;
-    f->end = (f->end + 1) & (f->size - 1);
-    if (unlikely(f->beg == f->end || f->bufmode == _IONBF ||
-                 (f->bufmode == _IOLBF && c == '\n'))) {
+    f->buf[f->beg++] = c;
+    if (f->beg == f->size || f->bufmode == _IONBF ||
+        (f->bufmode == _IOLBF && c == '\n')) {
       if (f->writer) {
-        return f->writer(f);
-      } else if (f->beg == f->end) {
-        return fseteof(f);
+        if (f->writer(f) == -1) return -1;
+      } else if (f->beg == f->size) {
+        f->beg = 0;
       }
     }
     return c;
   } else {
-    return fseteof(f);
+    return __fseteof(f);
   }
 }

libc/stdio/fputwc.c

@@ -17,11 +17,9 @@
 │ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA                │
 │ 02110-1301 USA                                                               │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/limits.h"
 #include "libc/stdio/internal.h"
 #include "libc/stdio/stdio.h"
-#include "libc/str/str.h"
-#include "libc/str/tpencode.internal.h"
+#include "libc/str/tpenc.h"
 
 /**
  * Writes wide character to stream.
@@ -29,15 +27,18 @@
  * @return wc if written or -1 w/ errno
  */
 wint_t fputwc(wchar_t wc, FILE *f) {
-  unsigned i, len;
-  char buf[MB_LEN_MAX];
+  uint64_t w;
   if (wc != -1) {
-    len = tpencode(buf, sizeof(buf), wc, false);
-    for (i = 0; i < len; ++i) {
-      if (fputc(buf[i], f) == -1) return -1;
-    }
+    w = tpenc(wc);
+    do {
+      if (fputc(w & 0xff, f) != -1) {
+        w >>= 8;
+      } else {
+        return -1;
+      }
+    } while (w);
     return wc;
   } else {
-    return fseteof(f);
+    return __fseteof(f);
   }
 }

libc/stdio/fread.c

@@ -41,7 +41,7 @@ size_t fread(void *buf, size_t stride, size_t count, FILE *f) {
     } else if (!(i % stride)) {
       return i / stride;
     } else {
-      return fseterr(f, EOVERFLOW);
+      return __fseterr(f, EOVERFLOW);
     }
   }
   return count;

libc/stdio/freadbuf.c

@@ -22,12 +22,12 @@
 #include "libc/stdio/internal.h"
 #include "libc/stdio/stdio.h"
 
-int freadbuf(FILE *f) {
+int __freadbuf(FILE *f) {
   ssize_t got;
-  got = read(f->fd, f->buf, f->size - 1);
-  if (got == -1) return fseterrno(f);
-  if (got == 0) return fseteof(f);
+  got = read(f->fd, f->buf, f->size);
+  if (got == -1) return __fseterrno(f);
+  if (got == 0) return __fseteof(f);
   f->beg = 0;
-  f->end = got & (f->size - 1);
+  f->end = got;
   return got;
 }

libc/stdio/freopen.c

@@ -86,7 +86,7 @@ FILE *freopen(const char *pathname, const char *mode, FILE *stream) {
               kNtFileAttributeNormal)) {
         return stream;
       } else {
-        winerr();
+        __winerr();
         return NULL;
       }
     }

libc/stdio/freplenish.c

@@ -24,6 +24,8 @@
 #include "libc/stdio/internal.h"
 #include "libc/stdio/stdio.h"
 
+/* TODO(jart): Delete or rework */
+
 /**
  * Fills empty space in buffer with whatever's available.
  *
@@ -34,11 +36,9 @@ int freplenish(FILE *f) {
   ssize_t rc;
   size_t got;
   struct iovec iov[2];
-
   if (f->beg == f->end) {
     f->beg = f->end = 0;
   }
-
   if (f->beg <= f->end) {
     if (f->beg) {
       iov[0].iov_base = f->buf + f->end;
@@ -57,14 +57,14 @@ int freplenish(FILE *f) {
   if (rc != -1) {
     if (rc) {
       got = rc;
-      f->end = (f->end + got) & (f->size - 1);
+      f->end = (f->end + got) % f->size;
       return got;
     } else {
-      return fseteof(f);
+      return __fseteof(f);
     }
   } else if (errno == EINTR || errno == EAGAIN) {
     return 0;
   } else {
-    return fseterrno(f);
+    return __fseterrno(f);
   }
 }

libc/stdio/fscanf.c

@@ -21,14 +21,25 @@
 #include "libc/stdio/stdio.h"
 
 /**
- * Stream decoder.
- * @see libc/fmt/vcscanf.h
+ * Decodes data from stream.
+ *
+ * To read a line of data from a well-formed trustworthy file:
+ *
+ *   int x, y;
+ *   char text[256];
+ *   fscanf(f, "%d %d %s\n", &x, &y, text);
+ *
+ * Please note that this function is brittle by default, which makes it
+ * a good fit for yolo coding. With some toil it can be used in a way
+ * that makes it reasonably hardened although getline() may be better.
+ *
+ * @see libc/fmt/vcscanf.c
  */
 int(fscanf)(FILE *stream, const char *fmt, ...) {
   int rc;
   va_list va;
   va_start(va, fmt);
-  rc = (vcscanf)((int (*)(void *))fgetc, stream, fmt, va);
+  rc = (vcscanf)((int (*)(void *))fgetc, (void *)ungetc, stream, fmt, va);
   va_end(va);
   return rc;
 }

libc/stdio/fseek.c

@@ -20,6 +20,7 @@
 #include "libc/calls/calls.h"
 #include "libc/errno.h"
 #include "libc/stdio/stdio.h"
+#include "libc/sysv/consts/o.h"
 
 /**
  * Repositions open file stream.
@@ -29,20 +30,32 @@
  * is in the EOF state, this function can be used to restore it without
  * needing to reopen the file.
  *
- * @param stream is a non-null stream handle
+ * @param f is a non-null stream handle
  * @param offset is the byte delta
  * @param whence can be SEET_SET, SEEK_CUR, or SEEK_END
  * @returns new offset or -1 on error
  */
-long fseek(FILE *stream, long offset, int whence) {
-  int skew = fflush(stream);
-  if (whence == SEEK_CUR && skew != -1) offset -= skew;
+long fseek(FILE *f, long offset, int whence) {
+  int skew;
   int64_t newpos;
-  if ((newpos = lseek(stream->fd, offset, whence)) != -1) {
-    stream->state = 0;
-    return newpos;
+  if (f->fd != -1) {
+    if (whence == SEEK_CUR && f->beg < f->end) {
+      offset -= f->end - f->beg;
+    }
+    if (f->beg && !f->end) {
+      f->writer(f);
+    }
+    if ((newpos = lseek(f->fd, offset, whence)) != -1) {
+      f->state = 0;
+      f->beg = 0;
+      f->end = 0;
+      return newpos;
+    } else {
+      f->state = errno == ESPIPE ? EBADF : errno;
+      return -1;
+    }
   } else {
-    stream->state = errno == ESPIPE ? EBADF : errno;
+    f->beg = offset % f->size;
     return -1;
   }
 }

libc/stdio/fseteof.c

@@ -19,6 +19,6 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/stdio/internal.h"
 
-long fseteof(FILE *f) {
-  return fseterr(f, -1);
+long __fseteof(FILE *f) {
+  return __fseterr(f, -1);
 }

libc/stdio/fseterr.c

@@ -21,7 +21,7 @@
 #include "libc/errno.h"
 #include "libc/stdio/internal.h"
 
-long fseterr(FILE *f, int err) {
+long __fseterr(FILE *f, int err) {
   if (!err) err = -1;
   f->state = f->state <= 0 ? err : f->state;
   if (err > 0) errno = err;

libc/stdio/fseterrno.c

@@ -20,4 +20,6 @@
 #include "libc/errno.h"
 #include "libc/stdio/internal.h"
 
-long fseterrno(FILE *f) { return fseterr(f, errno); }
+long __fseterrno(FILE *f) {
+  return __fseterr(f, errno);
+}

libc/stdio/ftell.c

@@ -26,4 +26,6 @@
  * @param stream is a non-null stream handle
  * @returns current byte offset from beginning of file, or -1
  */
-long ftell(FILE *stream) { return fseek(stream, 0, SEEK_CUR); }
+long ftell(FILE *stream) {
+  return fseek(stream, 0, SEEK_CUR);
+}

libc/stdio/fwrite.c

@@ -37,7 +37,7 @@ size_t fwrite(const void *data, size_t stride, size_t count, FILE *f) {
       if (!(i % stride)) {
         return i / stride;
       } else {
-        return fseterr(f, EOVERFLOW);
+        return __fseterr(f, EOVERFLOW);
       }
     }
   }

libc/stdio/fwritebuf.c

@@ -18,28 +18,21 @@
 │ 02110-1301 USA                                                               │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/calls.h"
-#include "libc/calls/internal.h"
-#include "libc/dce.h"
 #include "libc/errno.h"
-#include "libc/nt/files.h"
-#include "libc/runtime/runtime.h"
 #include "libc/stdio/internal.h"
-#include "libc/stdio/stdio.h"
+#include "libc/str/str.h"
 
-/**
- * One-shot writes data from stream buffer to underlying file or device.
- *
- * @param f is a non-null open stream handle
- * @return number of bytes written or -1 on error
- */
-int fwritebuf(FILE *f) {
-  ssize_t put;
-  unsigned bytes;
-  bytes = (f->beg < f->end ? f->end : f->size) - f->beg;
-  if ((put = write(f->fd, &f->buf[f->beg], bytes)) == -1) {
+int __fwritebuf(FILE *f) {
+  ssize_t wrote;
+  if ((wrote = write(f->fd, f->buf, f->beg)) == -1) {
     if (errno == EINTR) return 0;
-    return (int)fseterrno(f);
+    return __fseterrno(f);
   }
-  f->beg = (unsigned)((f->beg + put) & (f->size - 1));
-  return bytes;
+  if (wrote == f->beg) {
+    f->beg = 0;
+  } else {
+    memcpy(f->buf, f->buf + wrote, f->beg - wrote);
+    f->beg -= wrote;
+  }
+  return wrote;
 }

libc/stdio/g_stderr_init.S

@@ -35,10 +35,8 @@
 	ezlea	g_stderr_buf,cx
 	mov	%rcx,24(%rax)			#→ f.buf
 	movl	$BUFSIZ,32(%rax)		#→ f.size
-	ezlea	fwritebuf,cx
-	ezlea	fswritebuf,dx
-	testb	IsMetal()
-	cmove	%rcx,%rdx
+	ezlea	__fwritebuf,cx
+	mov	%rcx,%rdx
 	mov	%rdx,48(%rax)			#→ f.writer
 	mov	%rax,stderr(%rip)
 	.init.end 400,_init_g_stderr,globl,hidden

libc/stdio/g_stdin_init.S

@@ -31,10 +31,8 @@
 	ezlea	g_stdin_buf,cx
 	mov	%rcx,24(%rax)			#→ f.buf
 	movl	$BUFSIZ,32(%rax)		#→ f.size
-	ezlea	freadbuf,cx
-	ezlea	fsreadbuf,dx
-	testb	IsMetal()
-	cmove	%rcx,%rdx
+	ezlea	__freadbuf,cx
+	mov	%rcx,%rdx
 	mov	%rdx,40(%rax)			#→ f.reader
 	mov	%rax,stdin(%rip)
 	.init.end 400,_init_g_stdin,globl,hidden

libc/stdio/g_stdout_init.S

@@ -33,10 +33,8 @@
 	ezlea	g_stdout_buf,cx
 	mov	%rcx,24(%rax)			#→ f.buf
 	movl	$BUFSIZ,32(%rax)		#→ f.size
-	ezlea	fwritebuf,cx
-	ezlea	fswritebuf,dx
-	testb	IsMetal()
-	cmovz	%rcx,%rdx
+	ezlea	__fwritebuf,cx
+	mov	%rcx,%rdx
 	mov	%rdx,48(%rax)			#→ f.writer
 	mov	%rax,stdout(%rip)
 	.init.end 400,_init_g_stdout,globl,hidden

libc/stdio/getcmoar.c

@@ -1,32 +0,0 @@
-/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
-│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
-╞══════════════════════════════════════════════════════════════════════════════╡
-│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
-│                                                                              │
-│ This program is free software; you can redistribute it and/or modify         │
-│ it under the terms of the GNU General Public License as published by         │
-│ the Free Software Foundation; version 2 of the License.                      │
-│                                                                              │
-│ This program is distributed in the hope that it will be useful, but          │
-│ WITHOUT ANY WARRANTY; without even the implied warranty of                   │
-│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU             │
-│ General Public License for more details.                                     │
-│                                                                              │
-│ You should have received a copy of the GNU General Public License            │
-│ along with this program; if not, write to the Free Software                  │
-│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA                │
-│ 02110-1301 USA                                                               │
-╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/stdio/internal.h"
-#include "libc/stdio/stdio.h"
-
-int __getc_moar(FILE *f) {
-  int b;
-  if (f->beg == f->end) {
-    if (!f->reader) return fseteof(f);
-    if (f->reader(f) == -1) return -1;
-  }
-  b = f->buf[f->beg];
-  f->beg = (f->beg + 1) & (f->size - 1);
-  return b;
-}

libc/stdio/getdelim.c

@@ -51,7 +51,7 @@ ssize_t getdelim(char **line, size_t *n, int delim, FILE *f) {
       break;
     }
     if (i + 2 >= *n && !__grow(line, n, 1, 0)) {
-      fseterrno(f);
+      __fseterrno(f);
       break;
     }
     if (((*line)[i++] = c) == delim) {

libc/stdio/internal.h

@@ -12,13 +12,11 @@ extern unsigned char g_stderrbuf[BUFSIZ];
 int _fflushregister(FILE *) hidden;
 void _fflushunregister(FILE *) hidden;
 
-int freadbuf(FILE *) hidden;
-int fwritebuf(FILE *) hidden;
-int fsreadbuf(FILE *) hidden;
-int fswritebuf(FILE *) hidden;
-long fseteof(FILE *) hidden;
-long fseterrno(FILE *) hidden;
-long fseterr(FILE *, int) hidden;
+int __freadbuf(FILE *) hidden;
+int __fwritebuf(FILE *) hidden;
+long __fseteof(FILE *) hidden;
+long __fseterrno(FILE *) hidden;
+long __fseterr(FILE *, int) hidden;
 
 COSMOPOLITAN_C_END_
 #endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */

libc/stdio/scanf.c

@@ -28,7 +28,7 @@ int(scanf)(const char *fmt, ...) {
   int rc;
   va_list va;
   va_start(va, fmt);
-  rc = (vcscanf)((int (*)(void *))fgetc, stdin, fmt, va);
+  rc = (vcscanf)((int (*)(void *))fgetc, NULL, stdin, fmt, va);
   va_end(va);
   return rc;
 }

libc/stdio/serialstdio.c

@@ -1,56 +0,0 @@
-/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
-│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
-╞══════════════════════════════════════════════════════════════════════════════╡
-│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
-│                                                                              │
-│ This program is free software; you can redistribute it and/or modify         │
-│ it under the terms of the GNU General Public License as published by         │
-│ the Free Software Foundation; version 2 of the License.                      │
-│                                                                              │
-│ This program is distributed in the hope that it will be useful, but          │
-│ WITHOUT ANY WARRANTY; without even the implied warranty of                   │
-│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU             │
-│ General Public License for more details.                                     │
-│                                                                              │
-│ You should have received a copy of the GNU General Public License            │
-│ along with this program; if not, write to the Free Software                  │
-│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA                │
-│ 02110-1301 USA                                                               │
-╚─────────────────────────────────────────────────────────────────────────────*/
-#include "ape/lib/pc.h"
-#include "libc/nexgen32e/uart.internal.h"
-#include "libc/stdio/internal.h"
-#include "libc/stdio/stdio.h"
-
-static void fin(FILE *f) {
-  f->buf[f->end] = inb(0x3F8);
-  f->end = (f->end + 1) & (f->size - 1);
-}
-
-static void fout(FILE *f) {
-  outb(0x3F8, f->buf[f->beg]);
-  f->beg = (f->beg + 1) & (f->size - 1);
-}
-
-static int serialstdio(FILE *f, unsigned char status, void action(FILE *)) {
-  int block = 1;
-  unsigned tally = 0;
-  while (f->end != f->beg) {
-    if (!(inb(0x3F8 + UART_LSR) & status)) {
-      if (!block) break;
-      asm("pause");
-    } else {
-      action(f);
-      tally++;
-    }
-  }
-  return (int)tally;
-}
-
-int fsreadbuf(FILE *f) {
-  return serialstdio(f, UART_TTYDA, fin);
-}
-
-int fswritebuf(FILE *f) {
-  return serialstdio(f, UART_TTYTXR, fout);
-}

libc/stdio/stdio.h

@@ -18,7 +18,8 @@ typedef struct FILE {
   uint32_t beg;                  // 0x10
   uint32_t end;                  // 0x14
   uint8_t *buf;                  // 0x18
-  size_t size;                   // 0x20
+  uint32_t size;                 // 0x20
+  uint32_t nofree;               // 0x24
   int (*reader)(struct FILE *);  // 0x28
   int (*writer)(struct FILE *);  // 0x30
 } FILE;
@@ -99,10 +100,8 @@ int vfscanf(FILE *, const char *, va_list);
 │ cosmopolitan § standard i/o » optimizations                              ─╬─│┼
 ╚────────────────────────────────────────────────────────────────────────────│*/
 
-int __getc_moar(FILE *);
-
 #define putc(c, f) fputc(c, f)
-#define getc(f)    (f->beg + 1 < f->end ? f->buf[f->beg++] : __getc_moar(f))
+#define getc(f)    (f->beg < f->end ? f->buf[f->beg++] : fgetc(f))
 
 #if defined(__GNUC__) && !defined(__STRICT_ANSI__)
 #define printf(FMT, ...)     (printf)(PFLINK(FMT), ##__VA_ARGS__)

libc/stdio/ungetc.c

@@ -20,7 +20,7 @@
 #include "libc/stdio/stdio.h"
 
 int ungetc(int c, FILE *f) {
+  f->beg = (f->beg - 1) & (f->size - 1);
   f->buf[f->beg] = c;
-  f->beg = (f->beg - 1u) & (f->size - 1);
   return c;
 }

libc/stdio/vfscanf.c

@@ -25,5 +25,5 @@
  * @see libc/fmt/vcscanf.h
  */
 int(vfscanf)(FILE *stream, const char *fmt, va_list ap) {
-  return (vcscanf)((int (*)(void *))fgetc, stream, fmt, ap);
+  return (vcscanf)((void *)fgetc, (void *)ungetc, stream, fmt, ap);
 }

libc/stdio/vscanf.c

@@ -25,5 +25,5 @@
  * @see libc/fmt/vcscanf.h
  */
 int(vscanf)(const char *fmt, va_list ap) {
-  return (vcscanf)((int (*)(void *))fgetc, stdin, fmt, ap);
+  return (vcscanf)((int (*)(void *))fgetc, (void *)ungetc, stdin, fmt, ap);
 }