Commit 1ecb996 attempted to make read_lines() use the last column of
the terminal (as re_wrap() did). There were two problems with this:
- The size of the buffer allocated for lines wasn't increased to allow
for the extra character.
- The test for width overflow was moved after the point where the
next character was added to the buffer. This caused a buffer overflow
in certain circumstances.
For example, if the line beyond the end of the display was wider than
the display read_lines() would initially read the partial line into a
buffer. When the user moved down read_lines() would be called again
to ensure the rest of the line was read. This would place the next
character in the partial line before checking for overflow.
This can be fixed by moving the test for overflow back to where it was
before commit 1ecb996 and changing the comparison to `>` rather than
`>=`.
There are two other places where buffers are created without allowing
for width+1 characters.
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Test explicitly for REOPEN flags: update_num_lines is called
unconditionally so (num_lines != NOT_REGULAR_FILE) is also true when
num_lines contains a valid number of lines.
The call to fstat doesn't need to be in #if ENABLE_FEATURE_LESS_FLAGS:
the whole function is already in such a test.
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
When read_lines tests whether a character will fit on the current
line it checks the *next* character but in case of overflow doesn't
display the *current* one. This results in the last column of the
terminal never being used.
The test in re_wrap (used when the terminal width changes or line
numbers are enabled/disabled) is different: it does allow the use
of the final column.
function old new delta
read_lines 764 770 +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>
Much of the code refers to lines using indices into the flines
array (which splits lines into portions that fit on the terminal).
In some cases this is wrong and actual line numbers should be
used:
- when lines are being truncated rather than wrapped (-S flag)
- when line numbers have been entered by the user
Also fix a bug in numeric input and improve the display at EOF.
function old new delta
goto_lineno - 111 +111
cap_cur_fline - 101 +101
buffer_to_line - 56 +56
buffer_up 35 66 +31
less_main 2606 2615 +9
goto_match 125 127 +2
buffer_down 81 56 -25
buffer_line 64 - -64
------------------------------------------------------------------------------
(add/remove: 3/1 grow/shrink: 3/1 up/down: 310/-89) Total: 221 bytes
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Add a function to package the test that detects whether enough has
been read from the file to allow a screenful to be displayed.
Also use this to determine when to display '(END)' in the status
line. The previous code was incomplete and didn't handle truncated
lines (-S flag) properly.
function old new delta
at_end - 63 +63
status_print 111 109 -2
read_lines 819 764 -55
getch_nowait 319 264 -55
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/3 up/down: 63/-112) Total: -49 bytes
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Move the code to detect non-regular files to the point where the
file is being opened. If num_lines == READING_FILE guarantees
that the file is regular.
Detect when a file becomes unreadable between it first being opened
and the call to update_num_lines. Mark the file as being non-regular
so we don't try that again.
function old new delta
reinitialize 197 245 +48
update_num_lines 159 127 -32
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 48/-32) Total: 16 bytes
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Make verbose status messages (-m/-M flags) behave more like the
real `less` command:
- fix display of line numbers so they're correct whether lines are
being truncated (-S flag) or wrapped.
- don't display total lines or percentage when lines are read from
stdin: we don't have that information until we reach EOF. When
we do reach EOF the additional information is displayed.
- when lines are read from a file count the total number of lines
so that we can display percentages. Counting lines is avoided
until the information is actually needed. If the user pages to
EOF the separate read pass can be avoided entirely.
Fixes Bug 7586
function old new delta
m_status_print 195 382 +187
safe_lineno - 35 +35
reinitialize 172 182 +10
read_lines 675 685 +10
buffer_fill_and_print 178 169 -9
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 3/1 up/down: 242/-9) Total: 233 bytes
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Lines are rewrapped when the terminal width changes or line numbers
are enabled/disabled. The current calculation always adds eight to
the line length for a tab whereas it should only add enough to move
to the next tab stop.
This doesn't affect the display of lines, which is handled elsewhere
and gets tab stops right, but it does cause lines to be wrapped at
the wrong position.
Signed-off-by: Ron Yorston <rmy@frippery.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Line numbers are displayed incorrectly on lines that have a search
pattern highlighted. The problem can be fixed by moving the call to
lineno_str in print_found above the while loop that alters the value
of the line pointer. However, a more substantial rewrite results in
savings.
function old new delta
buffer_print 688 697 +9
.rodata 156077 156045 -32
lineno_str 85 - -85
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 1/1 up/down: 9/-117) Total: -108 bytes
Signed-off-by: Ron Yorston <rmy@frippery.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
The -S flag, to cause long lines to be truncated, was enabled by
FEATURE_LESS_DASHCMD. This is non-obvious and -S is useful even
if the '-' command isn't enabled.
function old new delta
.rodata 156045 156077 +32
packed_usage 30223 30244 +21
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 53/0) Total: 53 bytes
Signed-off-by: Ron Yorston <rmy@frippery.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
function old new delta
buffer_print 71 104 +33
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This makes "G" (goto end of input) command work as well as
/search_for_nonexistent_string: both will read to EOF now
even from somewhat slow input (such as kernel's "git log").
function old new delta
ndelay_on 35 43 +8
ndelay_off 35 43 +8
read_lines 695 691 -4
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/1 up/down: 16/-4) Total: 12 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
While at it, make ESC sequences more readable; and removed check for
isatty(stdin) in reset. Code shrink:
text data bss dec hex filename
884771 936 17216 902923 dc70b busybox_old
884723 936 17216 902875 dc6db busybox_unstripped
Signed-off-by: Marek Polacek <mmpolacek@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This change retains "or later" state! No licensing _changes_ here,
only form is adjusted (article, space between "GPL" and "v2" and so on).
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This makes line editing able to recognize case when
cursor was not at the beginning of the line. It may also
be adapted later to find out display size (serial line users
would love it).
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
