358 lines
7.5 KiB
C
358 lines
7.5 KiB
C
/* $NetBSD: input.c,v 1.1.1.4 1999/04/06 05:30:38 mrg Exp $ */
|
|
|
|
/*
|
|
* Copyright (c) 1984,1985,1989,1994,1995,1996,1999 Mark Nudelman
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice in the documentation and/or other materials provided with
|
|
* the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY
|
|
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
|
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
|
|
* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
|
|
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
|
|
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
|
|
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
|
|
* IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
|
|
/*
|
|
* High level routines dealing with getting lines of input
|
|
* from the file being viewed.
|
|
*
|
|
* When we speak of "lines" here, we mean PRINTABLE lines;
|
|
* lines processed with respect to the screen width.
|
|
* We use the term "raw line" to refer to lines simply
|
|
* delimited by newlines; not processed with respect to screen width.
|
|
*/
|
|
|
|
#include "less.h"
|
|
|
|
extern int squeeze;
|
|
extern int chopline;
|
|
extern int sigs;
|
|
extern int ignore_eoi;
|
|
extern POSITION start_attnpos;
|
|
extern POSITION end_attnpos;
|
|
#if HILITE_SEARCH
|
|
extern int hilite_search;
|
|
extern int size_linebuf;
|
|
#endif
|
|
|
|
/*
|
|
* Get the next line.
|
|
* A "current" position is passed and a "new" position is returned.
|
|
* The current position is the position of the first character of
|
|
* a line. The new position is the position of the first character
|
|
* of the NEXT line. The line obtained is the line starting at curr_pos.
|
|
*/
|
|
public POSITION
|
|
forw_line(curr_pos)
|
|
POSITION curr_pos;
|
|
{
|
|
POSITION new_pos;
|
|
register int c;
|
|
int blankline;
|
|
int endline;
|
|
|
|
if (curr_pos == NULL_POSITION)
|
|
{
|
|
null_line();
|
|
return (NULL_POSITION);
|
|
}
|
|
#if HILITE_SEARCH
|
|
if (hilite_search == OPT_ONPLUS)
|
|
/*
|
|
* If we are ignoring EOI (command F), only prepare
|
|
* one line ahead, to avoid getting stuck waiting for
|
|
* slow data without displaying the data we already have.
|
|
* If we're not ignoring EOI, we *could* do the same, but
|
|
* for efficiency we prepare several lines ahead at once.
|
|
*/
|
|
prep_hilite(curr_pos, curr_pos + 3*size_linebuf,
|
|
ignore_eoi ? 1 : -1);
|
|
#endif
|
|
if (ch_seek(curr_pos))
|
|
{
|
|
null_line();
|
|
return (NULL_POSITION);
|
|
}
|
|
|
|
prewind();
|
|
plinenum(curr_pos);
|
|
(void) ch_seek(curr_pos);
|
|
|
|
c = ch_forw_get();
|
|
if (c == EOI)
|
|
{
|
|
null_line();
|
|
return (NULL_POSITION);
|
|
}
|
|
blankline = (c == '\n' || c == '\r');
|
|
|
|
for (;;)
|
|
{
|
|
if (ABORT_SIGS())
|
|
{
|
|
null_line();
|
|
return (NULL_POSITION);
|
|
}
|
|
if (c == '\n' || c == EOI)
|
|
{
|
|
/*
|
|
* End of the line.
|
|
*/
|
|
new_pos = ch_tell();
|
|
endline = 1;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Append the char to the line and get the next char.
|
|
*/
|
|
if (pappend(c, ch_tell()-1))
|
|
{
|
|
/*
|
|
* The char won't fit in the line; the line
|
|
* is too long to print in the screen width.
|
|
* End the line here.
|
|
*/
|
|
if (chopline)
|
|
{
|
|
do
|
|
{
|
|
c = ch_forw_get();
|
|
} while (c != '\n' && c != EOI);
|
|
new_pos = ch_tell();
|
|
endline = 1;
|
|
} else
|
|
{
|
|
new_pos = ch_tell() - 1;
|
|
endline = 0;
|
|
}
|
|
break;
|
|
}
|
|
c = ch_forw_get();
|
|
}
|
|
pdone(endline);
|
|
|
|
if (squeeze && blankline)
|
|
{
|
|
/*
|
|
* This line is blank.
|
|
* Skip down to the last contiguous blank line
|
|
* and pretend it is the one which we are returning.
|
|
*/
|
|
while ((c = ch_forw_get()) == '\n' || c == '\r')
|
|
if (ABORT_SIGS())
|
|
{
|
|
null_line();
|
|
return (NULL_POSITION);
|
|
}
|
|
if (c != EOI)
|
|
(void) ch_back_get();
|
|
new_pos = ch_tell();
|
|
}
|
|
|
|
return (new_pos);
|
|
}
|
|
|
|
/*
|
|
* Get the previous line.
|
|
* A "current" position is passed and a "new" position is returned.
|
|
* The current position is the position of the first character of
|
|
* a line. The new position is the position of the first character
|
|
* of the PREVIOUS line. The line obtained is the one starting at new_pos.
|
|
*/
|
|
public POSITION
|
|
back_line(curr_pos)
|
|
POSITION curr_pos;
|
|
{
|
|
POSITION new_pos, begin_new_pos;
|
|
int c;
|
|
int endline;
|
|
|
|
if (curr_pos == NULL_POSITION || curr_pos <= ch_zero())
|
|
{
|
|
null_line();
|
|
return (NULL_POSITION);
|
|
}
|
|
#if HILITE_SEARCH
|
|
if (hilite_search == OPT_ONPLUS)
|
|
prep_hilite((curr_pos < 3*size_linebuf) ?
|
|
0 : curr_pos - 3*size_linebuf, curr_pos, -1);
|
|
#endif
|
|
if (ch_seek(curr_pos-1))
|
|
{
|
|
null_line();
|
|
return (NULL_POSITION);
|
|
}
|
|
|
|
if (squeeze)
|
|
{
|
|
/*
|
|
* Find out if the "current" line was blank.
|
|
*/
|
|
(void) ch_forw_get(); /* Skip the newline */
|
|
c = ch_forw_get(); /* First char of "current" line */
|
|
(void) ch_back_get(); /* Restore our position */
|
|
(void) ch_back_get();
|
|
|
|
if (c == '\n' || c == '\r')
|
|
{
|
|
/*
|
|
* The "current" line was blank.
|
|
* Skip over any preceding blank lines,
|
|
* since we skipped them in forw_line().
|
|
*/
|
|
while ((c = ch_back_get()) == '\n' || c == '\r')
|
|
if (ABORT_SIGS())
|
|
{
|
|
null_line();
|
|
return (NULL_POSITION);
|
|
}
|
|
if (c == EOI)
|
|
{
|
|
null_line();
|
|
return (NULL_POSITION);
|
|
}
|
|
(void) ch_forw_get();
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Scan backwards until we hit the beginning of the line.
|
|
*/
|
|
for (;;)
|
|
{
|
|
if (ABORT_SIGS())
|
|
{
|
|
null_line();
|
|
return (NULL_POSITION);
|
|
}
|
|
c = ch_back_get();
|
|
if (c == '\n')
|
|
{
|
|
/*
|
|
* This is the newline ending the previous line.
|
|
* We have hit the beginning of the line.
|
|
*/
|
|
new_pos = ch_tell() + 1;
|
|
break;
|
|
}
|
|
if (c == EOI)
|
|
{
|
|
/*
|
|
* We have hit the beginning of the file.
|
|
* This must be the first line in the file.
|
|
* This must, of course, be the beginning of the line.
|
|
*/
|
|
new_pos = ch_tell();
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Now scan forwards from the beginning of this line.
|
|
* We keep discarding "printable lines" (based on screen width)
|
|
* until we reach the curr_pos.
|
|
*
|
|
* {{ This algorithm is pretty inefficient if the lines
|
|
* are much longer than the screen width,
|
|
* but I don't know of any better way. }}
|
|
*/
|
|
if (ch_seek(new_pos))
|
|
{
|
|
null_line();
|
|
return (NULL_POSITION);
|
|
}
|
|
endline = 0;
|
|
loop:
|
|
begin_new_pos = new_pos;
|
|
prewind();
|
|
plinenum(new_pos);
|
|
(void) ch_seek(new_pos);
|
|
|
|
do
|
|
{
|
|
c = ch_forw_get();
|
|
if (c == EOI || ABORT_SIGS())
|
|
{
|
|
null_line();
|
|
return (NULL_POSITION);
|
|
}
|
|
new_pos++;
|
|
if (c == '\n')
|
|
{
|
|
endline = 1;
|
|
break;
|
|
}
|
|
if (pappend(c, ch_tell()-1))
|
|
{
|
|
/*
|
|
* Got a full printable line, but we haven't
|
|
* reached our curr_pos yet. Discard the line
|
|
* and start a new one.
|
|
*/
|
|
if (chopline)
|
|
{
|
|
endline = 1;
|
|
break;
|
|
}
|
|
pdone(0);
|
|
(void) ch_back_get();
|
|
new_pos--;
|
|
goto loop;
|
|
}
|
|
} while (new_pos < curr_pos);
|
|
|
|
pdone(endline);
|
|
|
|
return (begin_new_pos);
|
|
}
|
|
|
|
/*
|
|
* Set attnpos.
|
|
*/
|
|
public void
|
|
set_attnpos(pos)
|
|
POSITION pos;
|
|
{
|
|
int c;
|
|
|
|
if (pos != NULL_POSITION)
|
|
{
|
|
if (ch_seek(pos))
|
|
return;
|
|
for (;;)
|
|
{
|
|
c = ch_forw_get();
|
|
if (c == EOI)
|
|
return;
|
|
if (c != '\n' && c != '\r')
|
|
break;
|
|
pos++;
|
|
}
|
|
}
|
|
start_attnpos = pos;
|
|
for (;;)
|
|
{
|
|
c = ch_forw_get();
|
|
pos++;
|
|
if (c == EOI || c == '\n' || c == '\r')
|
|
break;
|
|
}
|
|
end_attnpos = pos;
|
|
}
|