--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/argp-fmtstream.c	Fri Oct 29 19:20:39 2010 -0600
@@ -0,0 +1,435 @@
+/* Word-wrapping and line-truncating streams
+   Copyright (C) 1997-1999, 2001-2003, 2005, 2009-2010 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 ((unsigned char) *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 ((unsigned char) *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 ((unsigned char) *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 ((unsigned char) *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 */