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-rw-r--r--argp/argp-fmtstream.c374
1 files changed, 374 insertions, 0 deletions
diff --git a/argp/argp-fmtstream.c b/argp/argp-fmtstream.c
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+/* Word-wrapping and line-truncating streams
+ Copyright (C) 1997 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Written by Miles Bader <miles@gnu.ai.mit.edu>.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Library General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ The GNU C Library 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
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If not,
+ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+/* 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
+
+#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 = malloc (sizeof (struct argp_fmtstream));
+ if (fs)
+ {
+ fs->stream = stream;
+
+ fs->lmargin = lmargin;
+ fs->rmargin = rmargin;
+ fs->wmargin = wmargin;
+ fs->point_col = 0;
+ fs->point_offs = 0;
+
+ fs->buf = 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;
+}
+#ifdef weak_alias
+weak_alias (__argp_make_fmtstream, argp_make_fmtstream)
+#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)
+ fwrite (fs->buf, 1, fs->p - fs->buf, fs->stream);
+ free (fs->buf);
+ free (fs);
+}
+#ifdef weak_alias
+weak_alias (__argp_fmtstream_free, argp_fmtstream_free)
+#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++)
+ putc (' ', 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) < 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. */
+ 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;
+ }
+
+ if (nextline - (nl + 1) < fs->wmargin)
+ /* 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. */
+ {
+ if (nl > fs->buf)
+ fwrite (fs->buf, 1, nl - fs->buf, fs->stream);
+ putc ('\n', fs->stream);
+ 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)
+ /* Add blanks up to the wrap margin column. */
+ for (i = 0; i < fs->wmargin; ++i)
+ *nl++ = ' ';
+ else
+ for (i = 0; i < fs->wmargin; ++i)
+ putc (' ', 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 (fs->end - fs->p < amount)
+ {
+ ssize_t wrote;
+
+ /* Flush FS's buffer. */
+ __argp_fmtstream_update (fs);
+
+ wrote = fwrite (fs->buf, 1, fs->p - fs->buf, fs->stream);
+ 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 (fs->end - fs->buf < amount)
+ /* Gotta grow the buffer. */
+ {
+ size_t new_size = fs->end - fs->buf + amount;
+ char *new_buf = realloc (fs->buf, new_size);
+
+ if (! new_buf)
+ {
+ __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, ...)
+{
+ size_t out;
+ 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;
+ size_guess += size_guess;
+
+ va_start (args, fmt);
+ out = __vsnprintf (fs->p, fs->end - fs->p, fmt, args);
+ va_end (args);
+ }
+ while (out == -1);
+
+ fs->p += out;
+
+ return out;
+}
+#ifdef weak_alias
+weak_alias (__argp_fmtstream_printf, argp_fmtstream_printf)
+#endif
+
+#endif /* !ARGP_FMTSTREAM_USE_LINEWRAP */
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