Commit Graph

326 Commits

Author SHA1 Message Date
Ron Yorston
852ffbee34 vi: fix buffer overrun; code shrink
It was possible for get_input_line() to store its NUL terminator
one character beyond the end of its buffer.

Code shrink in colon():

- Certain colon commands can be matched exactly, as any shorter
  string would be matched earlier, e.g. ':wq' versus ':write'.

- Command matching is now case sensitive so there's no need to
  check for 'N' or 'Q' suffixes.

- Rewrite how commands and arguments are split.

function                                             old     new   delta
colon                                               3848    3751     -97
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-97)             Total: -97 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-28 11:29:33 +02:00
Ron Yorston
dadd909746 vi: improvements to ':read' command
Improvements to ':read':

- When a file is read into the current buffer the cursor should be
  placed on the first line read.

- If invoked without supplying a filename the current filename should
  be used.  This is similar to how ':edit' works.

- The code for ':edit' included an explicit check that the current
  filename was non-empty.  Both vim and traditional vi accept non-empty
  filenames, only issuing an error message when an attempt to use such
  a name fails.

- Allow undo of a file read.

function                                             old     new   delta
file_insert                                          367     382     +15
colon                                               3841    3848      +7
.rodata                                           105236  105218     -18
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/1 up/down: 22/-18)              Total: 4 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-28 11:29:33 +02:00
Ron Yorston
e6bc8a29a9 vi: preserve state when switching file
When a new file is opened from an existing editing session the
following details should be preserved:

- the last command used;
- the last character searched for on a line.

function                                             old     new   delta
edit_file                                            849     835     -14
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-14)             Total: -14 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-28 11:29:33 +02:00
Ron Yorston
b9aaa375a3 vi: 'ZZ' should warn if there are more files to edit
When 'ZZ' was used to save the current file and more files were
available to edit BusyBox vi immediately moved on to the next file.
The correct behaviour is to issue a warning.

function                                             old     new   delta
do_cmd                                              4673    4724     +51
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/0 up/down: 51/0)               Total: 51 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-28 11:29:33 +02:00
Ron Yorston
09172582da vi: saving unnamed file in readonly mode
Suppose vi is started with the command 'vi -R', that is, in readonly
mode with no filename.  Attempting to save the file with 'ZZ' or ':w'
results in the message:

   '(null)' is read only

Skip the code which prints this if no filename was provided, thus
falling through to file_write() which gives the more helpful message
'No current filename'.

function                                             old     new   delta
colon                                               3867    3874      +7
do_cmd                                              4668    4673      +5
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 12/0)               Total: 12 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-28 11:29:33 +02:00
Ron Yorston
3b9233f05f vi: adjust conditional compilation of modifying_cmds
Since commit 74d565ff1 (vi: make context marks more like vi) the
list of commands that modify the text is no longer required when
FEATURE_VI_YANKMARK is enabled, only FEATURE_VI_DOT_CMD.

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-28 11:29:33 +02:00
Ron Yorston
7a8ceb4eb2 vi: changes to line addresses for colon commands
Make line addresses behave more like vi:

- Vi allows the user to enter an arbitrary number of addresses,
  though only the last two are used.  This simplifies get_address()
  by reducing the amount of state that needs to be carried.

- When a command requires a single address the last one entered is
  used.

- If addresses are separated by a ';' instead of a ',' the current
  line is updated to the left address.  This may be useful when a
  search is used to specify a range, e.g. ':/first/;/last/d'.

- When the last address is empty it should refer to the current line.

function                                             old     new   delta
colon                                               3855    3834     -21
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-21)             Total: -21 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-28 11:29:33 +02:00
Ron Yorston
f277c9eebb vi: make de-indentation with ctrl-D more like vim
Commit ac6495f6f (vi: allow ctrl-D to reduce indentation) treated
ctrl-D during autoindent as a backspace.  This was adequate for
indentation using tabs but doesn't work well with the expandtab
option.  In the latter case it's necessary to backspace over all
the spaces.

Make ctrl-D work correctly when spaces are present in the indent.

Also, make it behave more like vim:

- ctrl-D is independent of autoindent;
- indentation is reduced even when the cursor isn't positioned at
  the end of the indent.

function                                             old     new   delta
char_insert                                          679     717     +38
get_column                                             -      37     +37
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 1/0 up/down: 75/0)               Total: 75 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-20 11:21:43 +02:00
Ron Yorston
310ef23280 vi: add expandtab option
This implements the vim option expandtab in BusyBox vi.  From
vim help:

  In Insert mode: Use the appropriate number of spaces to insert a
  <Tab>.  Spaces are used in indents with the '>' and '<' commands and
  when 'autoindent' is on.  To insert a real tab when 'expandtab' is
  on, use CTRL-V<Tab>.

This implementation doesn't change how BusyBox vi handles autoindent:
it continues to copy the indentation from a neighbouring line.  If
that line has tabs in its indentation so too will the new line.

function                                             old     new   delta
char_insert                                          563     679    +116
next_column                                            -      48     +48
.rodata                                           105211  105236     +25
colon                                               3844    3855     +11
refresh                                             1000     982     -18
move_to_col                                           83      59     -24
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 3/2 up/down: 200/-42)           Total: 158 bytes

Signed-off-by: Peter D <urmum69@snopyta.org>
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-20 11:21:43 +02:00
Denys Vlasenko
b65e7f629e vi: move undo_queue_state in globals to other byte-sized members
function                                             old     new   delta
vi_main                                              278     275      -3
undo_queue_commit                                     62      56      -6
undo_push                                            374     362     -12
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-21)             Total: -21 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-15 23:18:40 +02:00
Ron Yorston
f227726838 vi: allow line addresses to have an offset
Line addresses in colon commands can be defined using an expression
that includes '+' or '-' operators.  The implementation follows
traditional vi:

- The first term in the expression defines an address.  It can be
  an absolute line number, '.', '$', a search or a marker.

- The second and subsequent terms must be non-negative integers.

- If the first term is missing '.' is assumed.  If the operator is
  missing addition is assumed.  If the final term in missing an
  offset of 1 is assumed.

Thus the following are valid addresses:

  .+1   .+   +   .1
  .-1   .-   -

The following are not valid (though they are in vim):

  .+$   .$   2+.

function                                             old     new   delta
colon                                               3701    3844    +143
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/0 up/down: 143/0)             Total: 143 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-15 13:09:12 +02:00
Ron Yorston
47f78913f7 vi: allow backward search to specify line address
It should be possible to use a backward search as a line address
in colon commands.

function                                             old     new   delta
colon                                               3661    3701     +40
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/0 up/down: 40/0)               Total: 40 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-15 13:09:12 +02:00
Ron Yorston
d488def0e4 vi: detect and warn about invalid line addresses
BusyBox vi didn't have proper handling for invalid markers or
unsuccessful searches in colon line addresses.  This could result
in the wrong lines being affected by a change.

Detect when an invalid address is specified, propagate an error
indicator up the call chain and issue a warning.

function                                             old     new   delta
colon                                               3604    3661     +57
.rodata                                           105195  105211     +16
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 73/0)               Total: 73 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-15 13:09:12 +02:00
Ron Yorston
5d1bb58b13 vi: code shrink colon line addresses
Remove some unnecessary code in get_one_address() and rewrite
get_address().

function                                             old     new   delta
colon                                               3325    3604    +279
get_one_address                                      342       -    -342
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 1/0 up/down: 279/-342)          Total: -63 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-15 13:09:12 +02:00
Ron Yorston
74d565ff1f vi: make context marks more like vi
The context marks that are automatically updated and can be used
with the "''" command didn't behave the same as in vi.  Marks
were only being set for certain editing commands when they should
have been set on successful movement commands.

Make BusyBox vi behave more like vi.

function                                             old     new   delta
.rodata                                           105179  105194     +15
do_cmd                                              4723    4668     -55
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 15/-55)            Total: -40 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-15 13:09:12 +02:00
Ron Yorston
47c3eaa22f vi: correct autoindent for 'O' command
Opening a line above the current line with the 'O' command should
use the current, not previous, line to determine how much to
autoindent.

function                                             old     new   delta
char_insert                                          531     563     +32
do_cmd                                              4746    4723     -23
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 32/-23)              Total: 9 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-15 13:09:12 +02:00
Ron Yorston
ac6495f6fb vi: allow ctrl-D to reduce indentation
When whitespace has been automatically added to a new line due to
autoindent entering ctrl-D should reduce the level of indentation.

Implement an approximation of this by treating ctrl-D as backspace.
For the common case of indentation using tabs this is good enough.
My attempt at a full implementation was three times bigger.

function                                             old     new   delta
char_insert                                          476     531     +55
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/0 up/down: 55/0)               Total: 55 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-15 13:09:12 +02:00
Ron Yorston
d6e653d667 vi: don't move cursor when yanking whole lines
When whole lines are yanked using 'yy' or 'Y' vi doesn't change the
cursor position.  Make BusyBox vi do the same.

function                                             old     new   delta
do_cmd                                              4776    4786     +10
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/0 up/down: 10/0)               Total: 10 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-15 13:09:12 +02:00
Ron Yorston
38ae0f3e3e vi: reset command count when specifying '0' range
Since commit a54450248 (vi: allow the '.' command to have a
repetition count) using '0' to specify a range doesn't work with
a non-zero repeat count, e.g. '1d0'.  Users wouldn't normally try
to do that but the '.' command does.

Add a special case in get_motion_char() to handle this.

function                                             old     new   delta
find_range                                           737     746      +9
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/0 up/down: 9/0)                 Total: 9 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-15 13:09:12 +02:00
Ron Yorston
033fa3d5c6 vi: code shrink motion by paragraph
Use a hand-coded loop to search for paragraph boundaries instead
of calling char_search().  We were using a loop anyway to skip
consecutive newlines.

function                                             old     new   delta
do_cmd                                              4792    4752     -40
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-40)             Total: -40 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-15 13:09:12 +02:00
Ron Yorston
d9d19896a9 vi: position cursor on last column of tab
Vi places the cursor on the last column of a tab character whereas
BusyBox vi puts it on the first.  This is disconcerting for
experienced vi users and makes it impossible to distinguish
visually between an empty line and one containing just a tab.

It wasn't always this way.  Prior to commit e3cbfb91d (vi: introduce
FEATURE_VI_8BIT) BusyBox vi also put the cursor on the last column.
However there were problems with cursor positioning when text was
inserted before a tab.  Commit eaabf0675 (vi: multiple fixes by
Natanael Copa) includes a partial attempt to fix this.  (The code is
still present but it's never executed.  Clever compilers optimise it
away.)

Revert the changes of commit e3cbfb91d and fix the insert problem
for all tabs, not just the first.

To quote Natanael:  "Costs a few bytes but its worth it imho".

function                                             old     new   delta
refresh                                              974    1000     +26
move_to_col                                           81      83      +2
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 28/0)               Total: 28 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-15 13:09:12 +02:00
Ron Yorston
9b2a3895ee vi: correctly record deleted characters
The undo queue didn't record deleted characters properly.  For
example, insert some text, backspace over a couple of characters
then exit insert mode.  At this point undo will restore two nulls
instead of the deleted characters.

The fix is in undo_push():  record the state of the UNDO_USE_SPOS
flag and clear it before using 'u_type'.

Also, update the comments to reflect the fact that UNDO_QUEUED_FLAG
isn't actually used.

function                                             old     new   delta
undo_push                                            443     435      -8
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-8)               Total: -8 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-15 13:09:12 +02:00
Alison Winters
7b5cbfd6d6 vi: allow writing to another file if this one is readonly
Version 2. Same change but rebased after Ron's improvements. Fixes bug
where if you open a read only file, you can't save it as a different
filename.

function                                             old     new   delta
colon                                               3160    3162      +2

Signed-off-by: Alison Winters <alisonatwork@outlook.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-13 19:30:16 +02:00
Ron Yorston
f4a9908b4c vi: improvements to reporting of changes
Traditional vi is mostly silent about the results of yank, delete,
change, undo or substitution commands.  Vim reports some details
about undo and substitution.  BusyBox vi is positively verbose in
comparison.

Make some improvements to BusyBox vi:

- Add vim-like reporting of changes caused by substitutions, of
  the form '64 substitutions on 53 lines'.  This replaces a fairly
  useless report of the result of the last change made.

- Ensure that the report about put operations correctly reflects the
  newly introduced repetition count.

- Commit 25d2592640 tried to limit status updates for delete and
  yank operations by detecting whether the register had changed.
  This didn't always work because the previously allocated memory
  could be reused for the new register contents.  Fix this by
  delaying freeing the old register until after the new one has
  been allocated.

- Add a configuration option to control verbose status reporting.
  This is on by default.  Turning it off make BusyBox vi as taciturn
  as traditional vi and saves 435 bytes.

function                                             old     new   delta
colon                                               3212    3292     +80
yank_status                                            -      74     +74
static.text_yank                                      99      86     -13
string_insert                                        130      76     -54
do_cmd                                              4842    4776     -66
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 1/3 up/down: 154/-133)           Total: 21 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-11 00:18:56 +02:00
Ron Yorston
99fb5f2144 vi: issue a warning on failure to find a character
When a search for a character within a line fails issue a warning.

function                                             old     new   delta
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/0 up/down: 0/0)                 Total: 0 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-11 00:18:56 +02:00
Ron Yorston
6220b4d531 vi: make the substitute command more like vi
Make the ':s/find/replace/g' command behave more like vi:

- the final delimiter is optional if no flag is specified;

- the cursor is moved to the first visible character of the last
  line where a substitution was made;

- a warning is displayed if no substitution was made.

function                                             old     new   delta
colon                                               3156    3212     +56
.rodata                                           105133  105142      +9
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 65/0)               Total: 65 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-11 00:18:55 +02:00
Ron Yorston
951c6ded3a vi: make put commands more like vi
Make the put commands 'p' and 'P' behave more like vi:

- allow a repetition count to be specified;

- when the text being inserted doesn't include a newline the cursor
  should be positioned at the end of the inserted text.

function                                             old     new   delta
do_cmd                                              4765    4842     +77
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/0 up/down: 77/0)               Total: 77 bytes

v2: Don't break build when FEATURE_VI_UNDO is disabled.

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-11 00:18:55 +02:00
Ron Yorston
a54450248b vi: allow the '.' command to have a repetition count
The '.' command repeats the last text change.  When it has a
repetition count replay the change the number of times requested.
Update the stored count if it changes.  For example,

   3dw     deletes 3 words
   .       deletes another 3 words
   2.      deletes 2 words and changes the stored count
   .       deletes 2 words

function                                             old     new   delta
do_cmd                                              4746    4781     +35
.rodata                                           105133  105138      +5
edit_file                                            887     849     -38
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/1 up/down: 40/-38)              Total: 2 bytes

v2: Change implementation to include repetition count in string.
    Otherwise repeating 'r' doesn't work properly.

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-11 00:18:55 +02:00
Ron Yorston
fe76569daa vi: allow 'r' command to be aborted, repeated
Make the 'r' command behave more like vi:

- abort the command if ESC is entered after the 'r';

- allow a repeat count to be entered before the 'r';

- if the repeat count exceeds the space available on the line don't
  change any characters and issue an alert.

function                                             old     new   delta
do_cmd                                              4679    4746     +67
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/0 up/down: 67/0)               Total: 67 bytes

v2: Don't break build when FEATURE_VI_UNDO is disabled.

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-11 00:18:55 +02:00
Ron Yorston
b18c7bf702 vi: improvements to undo
The left shift operator ('<') didn't support undo at all; right
shift ('>') required changes to be undone separately for each line.
Allow both types of shift to be undone as a single operation.

Also, neither traditional vi nor vim yank the lines being shifted by
the '<' and '>' commands, so remove that call to yank_delete();

When a repetition count was specified for the '~', 'x', 'X' or 's'
commands the changes had to be undone one character at a time.
Allow undo as a single operation (though the delete and change
parts of the 's' command still have to be undone separately).

function                                             old     new   delta
undo_push_insert                                      37      40      +3
do_cmd                                              4695    4663     -32
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 3/-32)             Total: -29 bytes

v2: Don't break build when FEATURE_VI_UNDO is  disabled.  Don't reset
    'undo_del' too early in '~' handling code.  Code shrink '~'.

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-11 00:18:55 +02:00
Ron Yorston
e577afca7c vi: more fixes to range selection by word
An example in my vi book presents different ways to fix the spelling
of the last word in a line:

   ... anyweigh.

With the cursor on the 'e' the command 'cway' should do the job.
Since commit 776b56d77, though, 'cw' incorrectly includes the full
stop in the range if we're on the last line of the file.

(Prior to commit 776b56d77 BusyBox vi got 'cw' right in this case but
'cW' wrong:  it *didn't* delete the full stop.)

Reinstate some of the bloat removed by the earlier commit to fix this.

Also, commit 7b4c2276a (vi: fix word operations across line boundaries)
incorrectly ignores whitespace after a single character word.  Adjust
the condition to avoid this.

function                                             old     new   delta
find_range                                           707     737     +30
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/0 up/down: 30/0)               Total: 30 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-11 00:18:55 +02:00
Ron Yorston
b7b1119d9f vi: improvements to range selection
Rewrite find_range(), pushing quite a bit of code from do_cmd()
down into it.

- The commands 'y', 'd', 'c', '<' and '>' can be given twice to
  specify a whole-line range.  BusyBox vi actually accepted any
  second character from that group, e.g. 'dc' or '<y', with the
  latter being accepted even if yank was disabled.  Require the
  two characters to match.

- '<' and '>' commands followed by ESC incorrectly issued an alert.

- Allow search commands and a marker (specified as "y'a", for example)
  to define a range for those operators that support it.

function                                             old     new   delta
find_range                                           518     707    +189
.rodata                                           105119  105133     +14
get_motion_char                                       68       -     -68
do_cmd                                              4860    4695    -165
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 2/1 up/down: 203/-233)          Total: -30 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-11 00:18:55 +02:00
Ron Yorston
7ce0e75c1f vi: code shrink search commands
Changes to search commands ('/', '?', 'n' and 'N'):

- Rewrite to be smaller and (possibly) clearer.

- Issue a warning when a repeat search is requested without a
  previous search having been made.

Vim and BusyBox vi support a repetition count for searches though
the original vi doesn't.  If the count exceeds the number of
occurrences of the search string the search may loop through the
file multiple times.

function                                             old     new   delta
.rodata                                           105135  105119     -16
do_cmd                                              4898    4860     -38
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-54)             Total: -54 bytes

Signed-off-by; Ron Yorston <rmy@pobox.com>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-11 00:18:55 +02:00
Ron Yorston
9f017d9db0 vi: changes to option handling
Since commit 70ee23399 (vi: code shrink) the ':set' command is
unable to process multiple options on a line.  Fix this by
temporarily null-terminating each option.

Change the default setting for all options to off to match vim.
Actually, 'flash' isn't an option in vim, only traditional vi,
where it's on by default.  In vim the corresponding option is
'visualbell' which defaults to off.  POSIX doesn't have either
of these.

Allow the abbreviation 'ts' for the 'tabstop' option.

Issue an error message if:

- an option is not implemented
- an option that takes a value has no '=' or has a 'no' prefix
- a boolean option has a '='

function                                             old     new   delta
colon                                               2944    3003     +59
.rodata                                           103171  103189     +18
vi_main                                              274     270      -4
setops                                                73       -     -73
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 2/1 up/down: 77/-77)              Total: 0 bytes

v2: Try harder to detect invalid options.  Thanks to Peter D for pointing
    this out.

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-04-08 12:50:01 +02:00
Ron Yorston
24198f652f vi: deal with invalid movements in shift commands
Since commit 25d259264 (vi: make buffer handling more vi-like)
find_range() can return early when an invalid movement is
specified.

The call to find_range() in the code that handles shift commands
('<' and '>') doesn't check for this condition.  Previously this
only resulted in the current line being shifted but it can now
result in a segfault.

Check for an invalid movement and notify the user without taking
any further action.

function                                             old     new   delta
do_cmd                                              4890    4898      +8
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/0 up/down: 8/0)                 Total: 8 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-03-30 14:51:27 +02:00
Ron Yorston
a25b4c2c42 vi: code shrink
- In the '+' and '-' commands the call to dot_skip_over_ws() is
  only needed for the final line processed so it can be moved out
  of the while loop.

- Marking sync_cursor() NOINLINE doesn't seem to offer the same
  advantages it did in 2009 (commit adf922ec2).

function                                             old     new   delta
refresh                                              694     974    +280
do_cmd                                              4900    4887     -13
sync_cursor                                          336       -    -336
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 1/1 up/down: 280/-349)          Total: -69 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-03-29 12:16:21 +02:00
Ron Yorston
d56da68057 vi: improve operations involving paragraph movement
Movement by paragraph doesn't always involve whole lines.  If the
cursor is positioned in the middle of a line deleting to either end
of the paragraph will result in one partial line and zero or more
full lines.

Adjust the end of ranges delimited by paragraph movement to more
closely match what vi does.

function                                             old     new   delta
find_range                                           467     518     +51
at_eof                                                 -      49     +49
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 1/0 up/down: 100/0)             Total: 100 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-03-29 12:16:21 +02:00
Ron Yorston
8b571bd7b5 vi: improve motion by paragraph
When moving by paragraph ('{' and '}'):

- Treat multiple empty lines as a single paragraph separator.

- When no paragraph separator is found move to the start or end of
  the file depending on the direction of motion.

function                                             old     new   delta
do_cmd                                              4821    4900     +79
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/0 up/down: 79/0)               Total: 79 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-03-29 12:16:21 +02:00
Ron Yorston
d3b74826c5 vi: allow repetition count for paragraph motion
The paragraph motion commands '{' and '}' should accept a count.

function                                             old     new   delta
do_cmd                                              5054    5071     +17
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/0 up/down: 17/0)               Total: 17 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-03-29 12:16:21 +02:00
Ron Yorston
1e84daf054 vi: allow motion count for change/delete/yank/shift
The motion that determines the range of a change, delete, yank
or shift operation can have its own count.  Thus the commands
'5dd' and 'd5d' are equivalent:  both delete 5 lines.

When the command itself also has a count the two values are
multiplied.  Thus the command '2d3w' deletes 6 words and '2D3G'
deletes from the current line to line 6.

(When dealing with structured data it might make sense to think in
units of 3 words so '2d3w' is deleting 2 such units.  It doesn't
seem quite as sensible to express 'delete from current line to line 6'
as '2D3G' but vi permits it.)

function                                             old     new   delta
get_motion_char                                        -      68     +68
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/0 up/down: 68/0)               Total: 68 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-03-29 12:16:21 +02:00
Ron Yorston
d4c46037a6 vi: support more commands for range selection
Add 'F', 'T' and '|' as commands that can be used to specify a
range for change/delete/yank operations.

function                                             old     new   delta
.rodata                                           105129  105135      +6
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/0 up/down: 6/0)                 Total: 6 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-03-29 12:16:21 +02:00
Ron Yorston
15f4ac3ca9 vi: improvements to character search within line
- Use a common routine to handle all commands to search for a
  character in a line.

- When searching for the nth occurrence of a character don't move
  the cursor if fewer than n occurrences are present.

- Add support for the 'T' command, search backwards for character
  after next occurrence of given character.

function                                             old     new   delta
do_cmd                                              4861    4805     -56
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-56)             Total: -56 bytes

v2: Add parentheses to avoid searches continuing past end of line.

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-03-29 12:16:21 +02:00
Ron Yorston
50a2db7dff vi: remember cursor column during vertical motion
When the 'j'/'k' commands or up/down arrow keys are used to move
the cursor vertically 'vi' remembers the original cursor column
and positions the cursor there if possible.  Also, if the '$'
command has been used to position the cursor at the end of a line
vertical movements keep the cursor at the end of the line.

Make BusyBox 'vi' do the same.

function                                             old     new   delta
refresh                                              674     694     +20
do_cmd                                              4853    4861      +8
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 28/0)               Total: 28 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-03-29 12:16:21 +02:00
Ron Yorston
18871c3f2b vi: 'G'/'M' commands move to first visible character
The 'G' command with no target (meaning 'go to last line') should
position the cursor on the first visible character of the line, as
it already does in other cases.

The 'M' command  should position the cursor on the first visible
character (as 'H' and 'L' already do).

function                                             old     new   delta
do_cmd                                              4842    4853     +11
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/0 up/down: 11/0)               Total: 11 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-03-29 12:16:21 +02:00
Ron Yorston
5ae25f40bd vi: don't overwrite existing file
If the name of the file being written doesn't match the current
filename and the output file already exists vi should issue a
warning and not overwrite the file.

Because the test only compares the file names it's somewhat over-
protective.  If the current file name is 'my_text' and the user tries
to save to './my_text' they'll be prevented from doing so.

function                                             old     new   delta
colon                                               3092    3151     +59
.rodata                                           105118  105146     +28
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 87/0)               Total: 87 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-03-29 12:16:21 +02:00
Ron Yorston
25d2592640 vi: make buffer handling more vi-like
Vi places text affected by change/delete/yank operations into a
buffer.  The contents of such buffers can be restored with the put
commands, 'p' or 'P'.  These behave differently depending on whether
the buffer contains whole lines or partial lines.  For whole lines
the text is copied into the file on the line before (P) or after
(p) the current line.  For partial lines the text is copied before
or after the current cursor position.

Whether an operation results in whole or partial lines depends on
the command used.

BusyBox vi treats any buffer with a newline as though it contained
whole lines.  This is incorrect.  Deleting multiple words across
a line boundary results in a buffer with a newline but not having
whole lines.

Rework how buffers are handled to behave more like vi.

function                                             old     new   delta
static.text_yank                                      79      99     +20
colon                                               3092    3097      +5
edit_file                                            885     887      +2
yank_delete                                          127     112     -15
.rodata                                           105139  105101     -38
find_range                                           514     467     -47
do_cmd                                              5088    4842    -246
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/4 up/down: 27/-346)          Total: -319 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-03-29 12:05:53 +02:00
Ron Yorston
776b56d774 vi: code shrink
I was puzzled by code in find_range() which handles forward word
movement.  It included a test to see if we're at the start of a
word.  Since these are forward word movements surely we'd expect to
be at the start of a word?  In fact, the test was intended to fix a
problem with changes to the last word in a file, as discussed in the
thread starting here:

   http://lists.busybox.net/pipermail/busybox/2004-January/044552.html

The code can be simplified by testing directly for end of file instead
of indirectly for not being at the start of a word.  Since trailing
whitespace is now handled in do_cmd() the code to back up off a newline
is no longer required.

function                                             old     new   delta
find_range                                           619     514    -105
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-105)           Total: -105 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-03-29 12:05:53 +02:00
Ron Yorston
7b4c2276a8 vi: fix word operations across line boundaries
Commit 4b49422a0 (vi: fix changes to word at end of line. Closes
11796) fixed a problem where an operation on a word at the end of
a line followed by a line starting with whitespace incorrectly
joined the lines.  However it also broke the case where operating
on multiple words across a line boundary *should* join the lines.

Fix this by detecting when trailing whitepace in a word operation
includes a newline.  Whitespace beyond the newline is excluded
from consideration.

function                                             old     new   delta
do_cmd                                              5083    5088      +5
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/0 up/down: 5/0)                 Total: 5 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-03-29 12:05:53 +02:00
Denys Vlasenko
70ee23399c vi: code shrink
function                                             old     new   delta
setops                                                85      73     -12
colon                                               2965    2915     -50
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-62)             Total: -62 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-03-01 14:41:39 +01:00
Alison Winters
63d9da322f vi: restore 0 offset after :set noXXX command
Fixes bug where commands after the first noXXX command are ignored.
    e.g. :set noic tabstop=4

While at it, stop recognizing "notabstop=NNN".

function                                             old     new   delta
colon                                               2990    2965     -25

Signed-off-by: Alison Winters <alisonatwork@outlook.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2021-03-01 14:26:36 +01:00