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-rw-r--r--stdio/linewrap.c183
1 files changed, 127 insertions, 56 deletions
diff --git a/stdio/linewrap.c b/stdio/linewrap.c
index e821cc3575..7f6576f29b 100644
--- a/stdio/linewrap.c
+++ b/stdio/linewrap.c
@@ -22,42 +22,27 @@ Cambridge, MA 02139, USA. */
#include <string.h>
#include <stdlib.h>
-/* We keep this data for each line-wrapping stream. */
-
-struct data
- {
- const size_t *lmargin, *rmargin; /* Left and right margins. */
- const size_t *wrapmargin; /* Margin to wrap to, or null to truncate. */
- size_t point; /* Current column of last chars flushed. */
-
- /* Original cookie and hooks from the stream. */
- void *cookie;
- void (*output) (FILE *, int);
- __io_close_fn *close;
- __io_fileno_fn *fileno;
- __io_seek_fn *seek;
- };
+#include <linewrap.h>
+
+void __line_wrap_output (FILE *, int);
/* Install our hooks into a stream. */
-
static inline void
-wrap_stream (FILE *stream, struct data *d)
+wrap_stream (FILE *stream, struct line_wrap_data *d)
{
- static void lwoutput (FILE *, int);
static __io_close_fn lwclose;
static __io_fileno_fn lwfileno;
stream->__cookie = d;
- stream->__room_funcs.__output = &lwoutput;
+ stream->__room_funcs.__output = &__line_wrap_output;
stream->__io_funcs.__close = &lwclose;
stream->__io_funcs.__fileno = &lwfileno;
stream->__io_funcs.__seek = NULL; /* Cannot seek. */
}
/* Restore a stream to its original state. */
-
static inline void
-unwrap_stream (FILE *stream, struct data *d)
+unwrap_stream (FILE *stream, struct line_wrap_data *d)
{
stream->__cookie = d->cookie;
stream->__room_funcs.__output = d->output;
@@ -72,41 +57,40 @@ unwrap_stream (FILE *stream, struct data *d)
static int
lwclose (void *cookie)
{
- struct data *d = cookie;
+ struct line_wrap_data *d = cookie;
return (*d->close) (d->cookie);
}
static int
lwfileno (void *cookie)
{
- struct data *d = cookie;
+ struct line_wrap_data *d = cookie;
return (*d->fileno) (d->cookie);
}
/* This function is called when STREAM must be flushed.
C is EOF or a character to be appended to the buffer contents. */
-
-static void
-lwoutput (FILE *stream, int c)
+void
+__line_wrap_output (FILE *stream, int c)
{
char *buf, *nl;
size_t len;
/* Extract our data and restore the stream's original cookie
and output function so writes we do really go out. */
- struct data *d = stream->__cookie;
+ struct line_wrap_data *d = stream->__cookie;
unwrap_stream (stream, d);
/* Scan the buffer for newlines. */
- for (buf = stream->__buffer;
- (buf < stream->__bufp || (c != EOF && c != '\n')) && !stream->__error)
+ buf = stream->__buffer;
+ while ((buf < stream->__bufp || (c != EOF && c != '\n')) && !stream->__error)
{
size_t r;
- if (d->point == 0 && d->lmargin && *d->lmargin != 0)
+ if (d->point == 0 && d->lmargin != 0)
{
/* We are starting a new line. Print spaces to the left margin. */
- const size_t pad = *d->lmargin;
+ const size_t pad = d->lmargin;
if (stream->__bufp + pad < stream->__put_limit)
{
/* We can fit in them in the buffer by moving the
@@ -141,8 +125,7 @@ lwoutput (FILE *stream, int c)
{
/* The buffer ends in a partial line. */
- if (!d->rmargin ||
- d->point + len + (c != EOF && c != '\n') <= d->rmargin)
+ if (d->point + len + (c != EOF && c != '\n') <= d->rmargin)
{
/* The remaining buffer text is a partial line and fits
within the maximum line width. Advance point for the
@@ -155,7 +138,7 @@ lwoutput (FILE *stream, int c)
the end of the buffer. */
nl = stream->__bufp;
}
- else if (!d->rmargin || d->point + (nl - buf) <= d->rmargin)
+ else if (d->point + (nl - buf) <= d->rmargin)
{
/* The buffer contains a full line that fits within the maximum
line width. Reset point and scan the next line. */
@@ -165,9 +148,9 @@ lwoutput (FILE *stream, int c)
}
/* This line is too long. */
- r = *d->rmargin;
+ r = d->rmargin;
- if (! d->wrapmargin)
+ if (d->wmargin < 0)
{
/* Truncate the line by overwriting the excess with the
newline and anything after it in the buffer. */
@@ -242,7 +225,7 @@ lwoutput (FILE *stream, int c)
/* Temporarily reset bufp to include just the first line. */
stream->__bufp = nl;
- if (nextline - (nl + 1) < d->wrap)
+ if (nextline - (nl + 1) < d->wmargin)
/* The margin needs more blanks than we removed.
Output the first line so we can use the space. */
(*d->output) (stream, '\n');
@@ -255,7 +238,7 @@ lwoutput (FILE *stream, int c)
d->point = 0;
/* Add blanks up to the wrap margin column. */
- for (i = 0; i < d->wrap; ++i)
+ for (i = 0; i < d->wmargin; ++i)
*stream->__bufp++ = ' ';
/* Copy the tail of the original buffer into the current buffer
@@ -284,19 +267,16 @@ lwoutput (FILE *stream, int c)
wrap_stream (stream, d);
}
-/* Modify STREAM so that it prefixes lines written on it with *LMARGIN
- spaces and limits them to *RMARGIN columns total. If WRAP is not null,
- words that extend past *RMARGIN are wrapped by replacing the whitespace
- before them with a newline and *WRAP spaces. Otherwise, chars beyond
- *RMARGIN are simply dropped until a newline. Returns STREAM after
- modifying it, or NULL if there was an error. The pointers passed are
- stored in the stream and so must remain valid until `line_unwrap_stream'
- is called; the values pointed to can be changed between stdio calls. */
-
+/* Modify STREAM so that it 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 STREAM after modifying it, or
+ NULL if there was an error. */
FILE *
-line_wrap_stream (FILE *stream, size_t *lmargin, size_t *rmargin, size_t *wrap)
+line_wrap_stream (FILE *stream, size_t lmargin, size_t rmargin, size_t wmargin)
{
- struct data *d = malloc (sizeof *d);
+ struct line_wrap_data *d = malloc (sizeof *d);
if (!d)
return NULL;
@@ -321,25 +301,116 @@ line_wrap_stream (FILE *stream, size_t *lmargin, size_t *rmargin, size_t *wrap)
to work if the stream is switched to full or no buffering. */
stream->__linebuf = 1;
-#define ref(arg) d->arg = arg
- ref (lmargin);
- ref (rmargin);
- ref (wrap);
-#undef ref
+ d->lmargin = lmargin;
+ d->rmargin = rmargin;
+ d->wmargin = wmargin;
return stream;
}
/* Remove the hooks placed in STREAM by `line_wrap_stream'. */
-
void
line_unwrap_stream (FILE *stream)
{
- struct data *d = stream->__cookie;
+ struct line_wrap_data *d = stream->__cookie;
unwrap_stream (stream, d);
free (d);
}
+/* Functions on wrapped streams. */
+
+/* Returns true if STREAM is line wrapped. */
+inline int
+line_wrapped (FILE *stream)
+{
+ return (stream->__room_funcs.__output == &__line_wrap_output);
+}
+
+/* If STREAM is not line-wrapped return -1, else return its left margin. */
+size_t
+line_wrap_lmargin (FILE *stream)
+{
+ if (! line_wrapped (stream))
+ return -1;
+ return ((struct line_wrap_data *)stream->__cookie)->lmargin;
+}
+
+/* If STREAM is not line-wrapped return -1, else set its left margin to
+ LMARGIN and return the old value. */
+size_t
+line_wrap_set_lmargin (FILE *stream, size_t lmargin)
+{
+ if (! line_wrapped (stream))
+ return -1;
+ else
+ {
+ struct line_wrap_data *d = stream->__cookie;
+ size_t old = d->lmargin;
+ d->lmargin = lmargin;
+ return old;
+ }
+}
+
+/* If STREAM is not line-wrapped return -1, else return its left margin. */
+size_t
+line_wrap_rmargin (FILE *stream)
+{
+ if (! line_wrapped (stream))
+ return -1;
+ return ((struct line_wrap_data *)stream->__cookie)->rmargin;
+}
+
+/* If STREAM is not line-wrapped return -1, else set its right margin to
+ RMARGIN and return the old value. */
+size_t
+line_wrap_set_rmargin (FILE *stream, size_t rmargin)
+{
+ if (! line_wrapped (stream))
+ return -1;
+ else
+ {
+ struct line_wrap_data *d = stream->__cookie;
+ size_t old = d->rmargin;
+ d->rmargin = rmargin;
+ return old;
+ }
+}
+
+/* If STREAM is not line-wrapped return -1, else return its wrap margin. */
+size_t
+line_wrap_wmargin (FILE *stream)
+{
+ if (! line_wrapped (stream))
+ return -1;
+ return ((struct line_wrap_data *)stream->__cookie)->wmargin;
+}
+
+/* If STREAM is not line-wrapped return -1, else set its left margin to
+ WMARGIN and return the old value. */
+size_t
+line_wrap_set_wmargin (FILE *stream, size_t wmargin)
+{
+ if (! line_wrapped (stream))
+ return -1;
+ else
+ {
+ struct line_wrap_data *d = stream->__cookie;
+ size_t old = d->wmargin;
+ d->wmargin = wmargin;
+ return old;
+ }
+}
+
+/* If STREAM is not line-wrapped return -1, else return the column number of
+ the current output point. */
+size_t
+line_wrap_point (FILE *stream)
+{
+ if (! line_wrapped (stream))
+ return -1;
+ return ((struct line_wrap_data *)stream->__cookie)->point;
+}
+
#ifdef TEST
int
main (int argc, char **argv)
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-18 01:40:33 +0000