--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/argp-fmtstream.c	Sun Aug 16 17:16:49 2009 +0000
@@ -0,0 +1,434 @@
+/* Word-wrapping and line-truncating streams
+   Copyright (C) 1997-1999,2001,2002,2003,2005 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Written by Miles Bader <miles@gnu.ai.mit.edu>.
+
+   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; either version 3 of the License, or
+   (at your option) any later version.
+
+   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, see <http://www.gnu.org/licenses/>.  */
+
+/* This package emulates glibc `line_wrap_stream' semantics for systems that
+   don't have that.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <ctype.h>
+
+#include "argp-fmtstream.h"
+#include "argp-namefrob.h"
+
+#ifndef ARGP_FMTSTREAM_USE_LINEWRAP
+
+#ifndef isblank
+#define isblank(ch) ((ch)==' ' || (ch)=='\t')
+#endif
+
+#if defined _LIBC && defined USE_IN_LIBIO
+# include <wchar.h>
+# include <libio/libioP.h>
+# define __vsnprintf(s, l, f, a) _IO_vsnprintf (s, l, f, a)
+#endif
+
+#define INIT_BUF_SIZE 200
+#define PRINTF_SIZE_GUESS 150
+
+/* Return an argp_fmtstream that outputs to STREAM, and which prefixes lines
+   written on it with LMARGIN spaces and limits them to RMARGIN columns
+   total.  If WMARGIN >= 0, words that extend past RMARGIN are wrapped by
+   replacing the whitespace before them with a newline and WMARGIN spaces.
+   Otherwise, chars beyond RMARGIN are simply dropped until a newline.
+   Returns NULL if there was an error.  */
+argp_fmtstream_t
+__argp_make_fmtstream (FILE *stream,
+		       size_t lmargin, size_t rmargin, ssize_t wmargin)
+{
+  argp_fmtstream_t fs;
+
+  fs = (struct argp_fmtstream *) malloc (sizeof (struct argp_fmtstream));
+  if (fs != NULL)
+    {
+      fs->stream = stream;
+
+      fs->lmargin = lmargin;
+      fs->rmargin = rmargin;
+      fs->wmargin = wmargin;
+      fs->point_col = 0;
+      fs->point_offs = 0;
+
+      fs->buf = (char *) malloc (INIT_BUF_SIZE);
+      if (! fs->buf)
+	{
+	  free (fs);
+	  fs = 0;
+	}
+      else
+	{
+	  fs->p = fs->buf;
+	  fs->end = fs->buf + INIT_BUF_SIZE;
+	}
+    }
+
+  return fs;
+}
+#if 0
+/* Not exported.  */
+#ifdef weak_alias
+weak_alias (__argp_make_fmtstream, argp_make_fmtstream)
+#endif
+#endif
+
+/* Flush FS to its stream, and free it (but don't close the stream).  */
+void
+__argp_fmtstream_free (argp_fmtstream_t fs)
+{
+  __argp_fmtstream_update (fs);
+  if (fs->p > fs->buf)
+    {
+#ifdef USE_IN_LIBIO
+      __fxprintf (fs->stream, "%.*s", (int) (fs->p - fs->buf), fs->buf);
+#else
+      fwrite_unlocked (fs->buf, 1, fs->p - fs->buf, fs->stream);
+#endif
+    }
+  free (fs->buf);
+  free (fs);
+}
+#if 0
+/* Not exported.  */
+#ifdef weak_alias
+weak_alias (__argp_fmtstream_free, argp_fmtstream_free)
+#endif
+#endif
+
+/* Process FS's buffer so that line wrapping is done from POINT_OFFS to the
+   end of its buffer.  This code is mostly from glibc stdio/linewrap.c.  */
+void
+__argp_fmtstream_update (argp_fmtstream_t fs)
+{
+  char *buf, *nl;
+  size_t len;
+
+  /* Scan the buffer for newlines.  */
+  buf = fs->buf + fs->point_offs;
+  while (buf < fs->p)
+    {
+      size_t r;
+
+      if (fs->point_col == 0 && fs->lmargin != 0)
+	{
+	  /* We are starting a new line.  Print spaces to the left margin.  */
+	  const size_t pad = fs->lmargin;
+	  if (fs->p + pad < fs->end)
+	    {
+	      /* We can fit in them in the buffer by moving the
+		 buffer text up and filling in the beginning.  */
+	      memmove (buf + pad, buf, fs->p - buf);
+	      fs->p += pad; /* Compensate for bigger buffer. */
+	      memset (buf, ' ', pad); /* Fill in the spaces.  */
+	      buf += pad; /* Don't bother searching them.  */
+	    }
+	  else
+	    {
+	      /* No buffer space for spaces.  Must flush.  */
+	      size_t i;
+	      for (i = 0; i < pad; i++)
+		{
+#ifdef USE_IN_LIBIO
+		  if (_IO_fwide (fs->stream, 0) > 0)
+		    putwc_unlocked (L' ', fs->stream);
+		  else
+#endif
+		    putc_unlocked (' ', fs->stream);
+		}
+	    }
+	  fs->point_col = pad;
+	}
+
+      len = fs->p - buf;
+      nl = memchr (buf, '\n', len);
+
+      if (fs->point_col < 0)
+	fs->point_col = 0;
+
+      if (!nl)
+	{
+	  /* The buffer ends in a partial line.  */
+
+	  if (fs->point_col + len < fs->rmargin)
+	    {
+	      /* The remaining buffer text is a partial line and fits
+		 within the maximum line width.  Advance point for the
+		 characters to be written and stop scanning.  */
+	      fs->point_col += len;
+	      break;
+	    }
+	  else
+	    /* Set the end-of-line pointer for the code below to
+	       the end of the buffer.  */
+	    nl = fs->p;
+	}
+      else if (fs->point_col + (nl - buf) < (ssize_t) fs->rmargin)
+	{
+	  /* The buffer contains a full line that fits within the maximum
+	     line width.  Reset point and scan the next line.  */
+	  fs->point_col = 0;
+	  buf = nl + 1;
+	  continue;
+	}
+
+      /* This line is too long.  */
+      r = fs->rmargin - 1;
+
+      if (fs->wmargin < 0)
+	{
+	  /* Truncate the line by overwriting the excess with the
+	     newline and anything after it in the buffer.  */
+	  if (nl < fs->p)
+	    {
+	      memmove (buf + (r - fs->point_col), nl, fs->p - nl);
+	      fs->p -= buf + (r - fs->point_col) - nl;
+	      /* Reset point for the next line and start scanning it.  */
+	      fs->point_col = 0;
+	      buf += r + 1; /* Skip full line plus \n. */
+	    }
+	  else
+	    {
+	      /* The buffer ends with a partial line that is beyond the
+		 maximum line width.  Advance point for the characters
+		 written, and discard those past the max from the buffer.  */
+	      fs->point_col += len;
+	      fs->p -= fs->point_col - r;
+	      break;
+	    }
+	}
+      else
+	{
+	  /* Do word wrap.  Go to the column just past the maximum line
+	     width and scan back for the beginning of the word there.
+	     Then insert a line break.  */
+
+	  char *p, *nextline;
+	  int i;
+
+	  p = buf + (r + 1 - fs->point_col);
+	  while (p >= buf && !isblank (*p))
+	    --p;
+	  nextline = p + 1;	/* This will begin the next line.  */
+
+	  if (nextline > buf)
+	    {
+	      /* Swallow separating blanks.  */
+	      if (p >= buf)
+		do
+		  --p;
+		while (p >= buf && isblank (*p));
+	      nl = p + 1;	/* The newline will replace the first blank. */
+	    }
+	  else
+	    {
+	      /* A single word that is greater than the maximum line width.
+		 Oh well.  Put it on an overlong line by itself.  */
+	      p = buf + (r + 1 - fs->point_col);
+	      /* Find the end of the long word.  */
+	      if (p < nl)
+		do
+		  ++p;
+		while (p < nl && !isblank (*p));
+	      if (p == nl)
+		{
+		  /* It already ends a line.  No fussing required.  */
+		  fs->point_col = 0;
+		  buf = nl + 1;
+		  continue;
+		}
+	      /* We will move the newline to replace the first blank.  */
+	      nl = p;
+	      /* Swallow separating blanks.  */
+	      do
+		++p;
+	      while (isblank (*p));
+	      /* The next line will start here.  */
+	      nextline = p;
+	    }
+
+	  /* Note: There are a bunch of tests below for
+	     NEXTLINE == BUF + LEN + 1; this case is where NL happens to fall
+	     at the end of the buffer, and NEXTLINE is in fact empty (and so
+	     we need not be careful to maintain its contents).  */
+
+	  if ((nextline == buf + len + 1
+	       ? fs->end - nl < fs->wmargin + 1
+	       : nextline - (nl + 1) < fs->wmargin)
+	      && fs->p > nextline)
+	    {
+	      /* The margin needs more blanks than we removed.  */
+	      if (fs->end - fs->p > fs->wmargin + 1)
+		/* Make some space for them.  */
+		{
+		  size_t mv = fs->p - nextline;
+		  memmove (nl + 1 + fs->wmargin, nextline, mv);
+		  nextline = nl + 1 + fs->wmargin;
+		  len = nextline + mv - buf;
+		  *nl++ = '\n';
+		}
+	      else
+		/* Output the first line so we can use the space.  */
+		{
+#ifdef _LIBC
+		  __fxprintf (fs->stream, "%.*s\n",
+			      (int) (nl - fs->buf), fs->buf);
+#else
+		  if (nl > fs->buf)
+		    fwrite_unlocked (fs->buf, 1, nl - fs->buf, fs->stream);
+		  putc_unlocked ('\n', fs->stream);
+#endif
+
+		  len += buf - fs->buf;
+		  nl = buf = fs->buf;
+		}
+	    }
+	  else
+	    /* We can fit the newline and blanks in before
+	       the next word.  */
+	    *nl++ = '\n';
+
+	  if (nextline - nl >= fs->wmargin
+	      || (nextline == buf + len + 1 && fs->end - nextline >= fs->wmargin))
+	    /* Add blanks up to the wrap margin column.  */
+	    for (i = 0; i < fs->wmargin; ++i)
+	      *nl++ = ' ';
+	  else
+	    for (i = 0; i < fs->wmargin; ++i)
+#ifdef USE_IN_LIBIO
+	      if (_IO_fwide (fs->stream, 0) > 0)
+		putwc_unlocked (L' ', fs->stream);
+	      else
+#endif
+		putc_unlocked (' ', fs->stream);
+
+	  /* Copy the tail of the original buffer into the current buffer
+	     position.  */
+	  if (nl < nextline)
+	    memmove (nl, nextline, buf + len - nextline);
+	  len -= nextline - buf;
+
+	  /* Continue the scan on the remaining lines in the buffer.  */
+	  buf = nl;
+
+	  /* Restore bufp to include all the remaining text.  */
+	  fs->p = nl + len;
+
+	  /* Reset the counter of what has been output this line.  If wmargin
+	     is 0, we want to avoid the lmargin getting added, so we set
+	     point_col to a magic value of -1 in that case.  */
+	  fs->point_col = fs->wmargin ? fs->wmargin : -1;
+	}
+    }
+
+  /* Remember that we've scanned as far as the end of the buffer.  */
+  fs->point_offs = fs->p - fs->buf;
+}
+
+/* Ensure that FS has space for AMOUNT more bytes in its buffer, either by
+   growing the buffer, or by flushing it.  True is returned iff we succeed. */
+int
+__argp_fmtstream_ensure (struct argp_fmtstream *fs, size_t amount)
+{
+  if ((size_t) (fs->end - fs->p) < amount)
+    {
+      ssize_t wrote;
+
+      /* Flush FS's buffer.  */
+      __argp_fmtstream_update (fs);
+
+#ifdef _LIBC
+      __fxprintf (fs->stream, "%.*s", (int) (fs->p - fs->buf), fs->buf);
+      wrote = fs->p - fs->buf;
+#else
+      wrote = fwrite_unlocked (fs->buf, 1, fs->p - fs->buf, fs->stream);
+#endif
+      if (wrote == fs->p - fs->buf)
+	{
+	  fs->p = fs->buf;
+	  fs->point_offs = 0;
+	}
+      else
+	{
+	  fs->p -= wrote;
+	  fs->point_offs -= wrote;
+	  memmove (fs->buf, fs->buf + wrote, fs->p - fs->buf);
+	  return 0;
+	}
+
+      if ((size_t) (fs->end - fs->buf) < amount)
+	/* Gotta grow the buffer.  */
+	{
+	  size_t old_size = fs->end - fs->buf;
+	  size_t new_size = old_size + amount;
+	  char *new_buf;
+
+	  if (new_size < old_size || ! (new_buf = realloc (fs->buf, new_size)))
+	    {
+	      __set_errno (ENOMEM);
+	      return 0;
+	    }
+
+	  fs->buf = new_buf;
+	  fs->end = new_buf + new_size;
+	  fs->p = fs->buf;
+	}
+    }
+
+  return 1;
+}
+
+ssize_t
+__argp_fmtstream_printf (struct argp_fmtstream *fs, const char *fmt, ...)
+{
+  int out;
+  size_t avail;
+  size_t size_guess = PRINTF_SIZE_GUESS; /* How much space to reserve. */
+
+  do
+    {
+      va_list args;
+
+      if (! __argp_fmtstream_ensure (fs, size_guess))
+	return -1;
+
+      va_start (args, fmt);
+      avail = fs->end - fs->p;
+      out = __vsnprintf (fs->p, avail, fmt, args);
+      va_end (args);
+      if ((size_t) out >= avail)
+	size_guess = out + 1;
+    }
+  while ((size_t) out >= avail);
+
+  fs->p += out;
+
+  return out;
+}
+#if 0
+/* Not exported.  */
+#ifdef weak_alias
+weak_alias (__argp_fmtstream_printf, argp_fmtstream_printf)
+#endif
+#endif
+
+#endif /* !ARGP_FMTSTREAM_USE_LINEWRAP */