201 lines
6.3 KiB
C
201 lines
6.3 KiB
C
/* Word-wrapping and line-truncating streams.
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Copyright (C) 1996 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If
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not, write to the Free Software Foundation, Inc., 675 Mass Ave,
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Cambridge, MA 02139, USA. */
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#ifndef __LINEWRAP_H__
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#define __LINEWRAP_H__
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#include <stdio.h>
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#include <ctype.h>
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#include <string.h>
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#include <features.h>
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#include <string.h> /* Need size_t. */
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__BEGIN_DECLS
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/* We keep this data for each line-wrapping stream. */
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struct line_wrap_data
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{
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size_t lmargin, rmargin; /* Left and right margins. */
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ssize_t wmargin; /* Margin to wrap to, or -1 to truncate. */
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/* Point in stdio buffer to which we've processed for wrapping, but
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not output. */
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size_t point_offs;
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/* Output column at POINT_OFFS, or -1 meaning 0 but don't add lmargin. */
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ssize_t point_col;
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/* Original cookie and hooks from the stream. */
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void *cookie;
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void (*output) (FILE *, int);
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__io_close_fn *close;
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__io_fileno_fn *fileno;
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__io_seek_fn *seek;
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};
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/* Modify STREAM so that it prefixes lines written on it with LMARGIN spaces
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and limits them to RMARGIN columns total. If WMARGIN >= 0, words that
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extend past RMARGIN are wrapped by replacing the whitespace before them
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with a newline and WMARGIN spaces. Otherwise, chars beyond RMARGIN are
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simply dropped until a newline. Returns STREAM after modifying it, or
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NULL if there was an error. */
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FILE *line_wrap_stream (FILE *stream,
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size_t lmargin, size_t rmargin, ssize_t wmargin);
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/* Remove the hooks placed in STREAM by `line_wrap_stream'. */
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void line_unwrap_stream (FILE *stream);
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/* Returns true if STREAM is line wrapped. */
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extern inline int line_wrapped (FILE *stream);
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/* If STREAM is not line-wrapped return -1, else return its left margin. */
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extern size_t line_wrap_lmargin (FILE *stream);
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/* If STREAM is not line-wrapped return -1, else set its left margin to
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LMARGIN and return the old value. */
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extern size_t line_wrap_set_lmargin (FILE *stream, size_t lmargin);
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/* If STREAM is not line-wrapped return -1, else return its left margin. */
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extern size_t line_wrap_rmargin (FILE *stream);
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/* If STREAM is not line-wrapped return -1, else set its right margin to
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RMARGIN and return the old value. */
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extern size_t line_wrap_set_rmargin (FILE *stream, size_t rmargin);
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/* If STREAM is not line-wrapped return -1, else return its wrap margin. */
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extern size_t line_wrap_wmargin (FILE *stream);
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/* If STREAM is not line-wrapped return -1, else set its left margin to
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WMARGIN and return the old value. */
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extern size_t line_wrap_set_wmargin (FILE *stream, size_t wmargin);
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/* If STREAM is not line-wrapped return -1, else return the column number of
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the current output point. */
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extern size_t line_wrap_point (FILE *stream);
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#ifdef __OPTIMIZE__
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extern void __line_wrap_output (FILE *, int); /* private */
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/* If STREAM is not line-wrapped, return 0. Otherwise all pending text
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buffered text in STREAM so that the POINT_OFFS field refers to the last
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position in the stdio buffer, and return the line wrap state object for
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STREAM. Since all text has been processed, this means that (1) the
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POINT_COL field refers to the column at which any new text would be added,
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and (2) any changes to the margin parameters will only affect new text. */
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extern struct line_wrap_data *__line_wrap_update (FILE *stream); /* private */
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/* Returns true if STREAM is line wrapped. */
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extern inline int
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line_wrapped (FILE *stream)
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{
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return (stream->__room_funcs.__output == &__line_wrap_output);
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}
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/* If STREAM is not line-wrapped return -1, else return its left margin. */
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extern inline size_t
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line_wrap_lmargin (FILE *stream)
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{
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if (! line_wrapped (stream))
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return -1;
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return ((struct line_wrap_data *)stream->__cookie)->lmargin;
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}
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/* If STREAM is not line-wrapped return -1, else set its left margin to
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LMARGIN and return the old value. */
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extern inline size_t
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line_wrap_set_lmargin (FILE *stream, size_t lmargin)
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{
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struct line_wrap_data *d = __line_wrap_update (stream);
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if (d)
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{
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size_t old = d->lmargin;
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d->lmargin = lmargin;
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return old;
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}
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else
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return -1;
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}
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/* If STREAM is not line-wrapped return -1, else return its left margin. */
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extern inline size_t
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line_wrap_rmargin (FILE *stream)
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{
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if (! line_wrapped (stream))
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return -1;
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return ((struct line_wrap_data *)stream->__cookie)->rmargin;
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}
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/* If STREAM is not line-wrapped return -1, else set its right margin to
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RMARGIN and return the old value. */
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extern inline size_t
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line_wrap_set_rmargin (FILE *stream, size_t rmargin)
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{
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struct line_wrap_data *d = __line_wrap_update (stream);
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if (d)
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{
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size_t old = d->rmargin;
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d->rmargin = rmargin;
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return old;
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}
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else
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return -1;
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}
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/* If STREAM is not line-wrapped return -1, else return its wrap margin. */
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extern inline size_t
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line_wrap_wmargin (FILE *stream)
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{
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if (! line_wrapped (stream))
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return -1;
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return ((struct line_wrap_data *)stream->__cookie)->wmargin;
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}
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/* If STREAM is not line-wrapped return -1, else set its left margin to
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WMARGIN and return the old value. */
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extern inline size_t
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line_wrap_set_wmargin (FILE *stream, size_t wmargin)
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{
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struct line_wrap_data *d = __line_wrap_update (stream);
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if (d)
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{
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size_t old = d->wmargin;
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d->wmargin = wmargin;
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return old;
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}
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else
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return -1;
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}
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/* If STREAM is not line-wrapped return -1, else return the column number of
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the current output point. */
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extern inline size_t
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line_wrap_point (FILE *stream)
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{
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struct line_wrap_data *d = __line_wrap_update (stream);
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return d ? (d->point_col >= 0 ? d->point_col : 0) : -1;
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}
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#endif /* Optimizing. */
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__END_DECLS
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#endif /* __LINEWRAP_H__ */
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