mark@nsc-pdc.UUCP (Mark Nudelman) (09/18/85)
I have made some bug fixes and improvements to my recently
posted paginator, less. Included below are the diffs.
First, a summary of the changes:
* Due to popular demand, I have allowed any character
to break out of the "press RETURN" messages; any
char other than return or space is interpreted
as a command. The old code is under "#if ONLY_RETURN"
for the benefit of anyone who liked the old way.
* Also by popular demand, I have added some new commands
as synonyms for existing commands, mainly control
characters like ^F, ^B, ^U, ^D for f, b, u, d.
* Pattern searching has been speeded up
(by a factor of 2 on our Vax 4.2 system).
* New command "%" is a synonym for "p".
(Thanks to Andy Tannenbaum for this idea.)
* Shell and editor escapes now correctly reinitialize
the terminal when less resumes.
(Thanks to Mike Kersenbrock for finding this one.)
* Minor bug with interrupts is fixed.
("n" command wouldn't work after an interrupt).
* Not-so-minor bug fix: search for N-th occurence
of a pattern did not work when N > 1.
* Several other little changes which I
just couldn't keep my fingers from typing.
I have included index lines for the benefit of people who use "patch".
As usual, feel free to send mail with comments, suggestions, bugs, etc.
Mark Nudelman ihnp4!nsc!nsc-pdc!mark
National Semiconductor tektronix!reed!nsc-pdc!mark
-------------------- diffs start here ---------------------------------
Index: command.c
5a6,7
> #include "position.h"
> #include <setjmp.h>
6a9
> extern jmp_buf main_loop;
22a26
> static char last_mcc; /* The previous mcc */
115a120
> cp = cmdbuf;
177c182
< if (cp > cmdbuf)
---
> if (cp > cmdbuf && position(TOP) == NULL_POSITION)
206d210
< register int last_mcc = 0;
208c212
< mcc = 0;
---
> mcc = last_mcc = 0;
209a214
> setjmp(main_loop);
262,267c267
< lower_left();
< putc('\n');
< flush();
< raw_mode(0);
< system(cmdbuf);
< raw_mode(1);
---
> lsystem(cmdbuf);
312a313
> case CONTROL('F'):
319a321
> case CONTROL('B'):
329a332
> case CONTROL('E'):
340a344,345
> case CONTROL('K'):
> case CONTROL('Y'):
350a356
> case CONTROL('D'):
361a368
> case CONTROL('U'):
378a386,387
> case CONTROL('R'):
> case CONTROL('L'):
396a406
> case '%':
421a432
> case CONTROL('G'):
508,511d518
< lower_left();
< clear_eol();
< flush();
< raw_mode(0);
513,514c520
< system(cmdbuf);
< raw_mode(1);
---
> lsystem(cmdbuf);
Index: funcs.h
2d1
< public char * eq_message ();
14a14
> public void jump_loc ();
26a27
> public int onscreen ();
47a49
> public void eos_clear ();
58a61,62
> public POSITION forw_raw_line ();
> public POSITION back_raw_line ();
60a65
> public void lsystem ();
Index: help.c
34c34
< puts("p * Position to N percent into the file.\n");
---
> puts("p, % * Position to N percent into the file.\n");
Index: input.c
27,28d31
< {
< line = NULL;
30d32
< }
34,35d35
< {
< line = NULL;
37d36
< }
101,102d99
< {
< line = NULL;
104d100
< }
126,127d121
< {
< line = NULL;
129d122
< }
171,172d163
< {
< line = NULL;
174d164
< }
Index: less.h
53a54
> #define CONTROL(c) ((c)&037)
Index: less.l
89a90,92
> .IP \%
> Same as p.
> .PP
288,294d290
< .PP
< Searches will not find a string which has been split due
< to line folding.
< .sp
< Tabs in the input are translated into the appropriate number of spaces,
< so a search pattern which includes a tab character will always fail.
< Use the pattern "\ *" instead.
Index: line.c
245a246,346
>
> /*
> * Analogous to forw_line(), but deals with "raw lines":
> * lines which are not split for screen width.
> * {{ This is supposed to be more efficient than forw_line(). }}
> */
> public POSITION
> forw_raw_line(curr_pos)
> POSITION curr_pos;
> {
> register char *p;
> register int c;
> POSITION new_pos;
>
> if (curr_pos == NULL_POSITION || ch_seek(curr_pos) ||
> (c = ch_forw_get()) == EOF)
> return (NULL_POSITION);
>
> p = linebuf;
>
> for (;;)
> {
> if (c == '\n' || c == EOF)
> {
> new_pos = ch_tell();
> break;
> }
> if (p >= &linebuf[sizeof(linebuf)-1])
> {
> /*
> * Overflowed the input buffer.
> * Pretend the line ended here.
> * {{ The line buffer is supposed to be big
> * enough that this never happens. }}
> */
> new_pos = ch_tell() - 1;
> break;
> }
> *p++ = c;
> c = ch_forw_get();
> }
> *p = '\0';
> line = linebuf;
> return (new_pos);
> }
>
> /*
> * Analogous to back_line(), but deals with "raw lines".
> * {{ This is supposed to be more efficient than back_line(). }}
> */
> public POSITION
> back_raw_line(curr_pos)
> POSITION curr_pos;
> {
> register char *p;
> register int c;
> POSITION new_pos;
>
> if (curr_pos == NULL_POSITION || curr_pos <= (POSITION)0 ||
> ch_seek(curr_pos-1))
> return (NULL_POSITION);
>
> p = &linebuf[sizeof(linebuf)];
> *--p = '\0';
>
> for (;;)
> {
> 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 == EOF)
> {
> /*
> * 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 = (POSITION)0;
> break;
> }
> if (p <= linebuf)
> {
> /*
> * Overflowed the input buffer.
> * Pretend the line ended here.
> */
> new_pos = ch_tell() + 1;
> break;
> }
> *--p = c;
> }
> line = p;
> return (new_pos);
> }
Index: main.c
213c213
< if (setjmp(main_loop) == 0)
---
> /*if (setjmp(main_loop) == 0)*/
Index: output.c
12c12,13
<
---
> extern char *first_cmd;
>
144a146
> static char buf[2];
152a155
> #if ONLY_RETURN
154a158,165
> #else
> c = getc();
> if (c != '\n' && c != '\r' && c != ' ')
> {
> buf[0] = c;
> first_cmd = buf;
> }
> #endif
Index: position.c
94a95,113
>
> /*
> * See if the byte at a specified position is currently on the screen.
> * Check the position table to see if the position falls within its range.
> * Return the position table entry if found, -1 if not.
> */
> public int
> onscreen(pos)
> POSITION pos;
> {
> register int i;
>
> if (pos < table[0])
> return (-1);
> for (i = 1; i < sc_height; i++)
> if (pos < table[i])
> return (i-1);
> return (-1);
> }
Index: prim.c
68a69
> line = NULL;
112a114
> line = NULL;
269d270
< int c;
280a282,283
> jump_loc(pos);
> }
281a285,291
> public void
> jump_loc(pos)
> POSITION pos;
> {
> register int c;
> register int nline;
>
291a302,312
> * See if the line is currently displayed.
> * If so, just scroll there.
> */
> if ((nline = onscreen(pos)) >= 0)
> {
> forw(nline, position(BOTTOM_PLUS_ONE), 1);
> return;
> }
>
> /*
> * Line is not on screen.
316,317c337
< POSITION pos, new_pos;
< register int lines_from_top;
---
> POSITION pos, linepos;
399d418
< lines_from_top = sc_height + 1;
407d425
< lines_from_top = 0;
415d432
< lines_from_top = 1;
423d439
< lines_from_top = sc_height + 1;
434d449
< new_pos = pos;
452,453c467,468
< * Read the next line, and remember the
< * starting position of the line after that.
---
> * Read the next line, and save the
> * starting position of that line in linepos.
455,457c470,471
< pos = new_pos;
< new_pos = forw_line(pos);
< lines_from_top++;
---
> linepos = pos;
> pos = forw_raw_line(pos);
461c475,476
< * Read the previous line.
---
> * Read the previous line and save the
> * starting position of that line in linepos.
463,464c478,479
< pos = back_line(pos);
< lines_from_top--;
---
> pos = back_raw_line(pos);
> linepos = pos;
467c482
< if (line == NULL)
---
> if (pos == NULL_POSITION)
496,517c511
<
< if (lines_from_top > 0 && lines_from_top < sc_height)
< {
< /*
< * Scroll forward.
< */
< clear_eol();
< forw(lines_from_top-1, position(BOTTOM_PLUS_ONE), 1);
< } else if (lines_from_top < 0 && -lines_from_top < sc_height)
< {
< /*
< * Scroll backwards.
< */
< clear_eol();
< back(-lines_from_top, position(TOP), 1);
< } else
< {
< /*
< * Clear and paint screen.
< */
< prepaint(pos);
< }
---
> jump_loc(linepos);
Index: signal.c
135a136,153
>
> /*
> * Pass the specified command to a shell to be executed.
> * Like plain "system()", but handles resetting terminal modes, etc.
> */
> public void
> lsystem(cmd)
> char *cmd;
> {
> lower_left();
> clear_eol();
> deinit();
> flush();
> raw_mode(0);
> system(cmd);
> raw_mode(1);
> init();
> }
Index: version.c
71a72,73
> * v41: ONLY_RETURN, control char commands, 9/17/85 mark
> * faster search, other minor fixes.
75c77
< char version[] = "@(#) less version 40";
---
> char version[] = "@(#) less version 41";