Commit Graph
17 Commits
Author SHA1 Message Date
Ron Yorston 26ccd3d062 less: fix botched attempt to use last column
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>
2015-08-16 18:54:49 +02:00
Ron Yorston b27cf31003 less: further tweaks to regular file detection
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>
2015-08-03 16:41:19 +02:00
Ron Yorston 1ecb996fd2 less: allow use of last column of terminal
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>
2015-07-31 16:22:09 +02:00
Ron Yorston d542d183e1 less: fix line number confusion
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>
2015-07-31 16:22:08 +02:00
Ron Yorston ad1b4d5882 less: add a function to detect when display is at end of file
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>
2015-07-31 16:22:08 +02:00
Ron Yorston 70b84be9e8 less: rearrange detection of non-regular files
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>
2015-07-31 16:22:07 +02:00
Ron Yorston 159e032bf4 less: move code to count lines into a separate function
function                                             old     new   delta
update_num_lines                                       -     159    +159
m_status_print                                       409     266    -143
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/1 up/down: 159/-143)           Total: 16 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2015-07-31 16:22:07 +02:00
Ron Yorston ae1a9e899e less: fix numeric input
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2015-07-31 15:33:53 +02:00
Ron Yorston 193ba408a4 less: improvements to verbose status messages
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>
2015-07-21 22:28:09 +02:00
Ron Yorston 523006798c testsuite: add some tests for ash
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2015-05-18 10:13:21 +02:00
Ron Yorston 417622cc2e ash: fix breakage of ${v/pat/str}
The commit

   ash: move parse-time quote flag detection to run-time

breaks pattern substitution in parameter expansion.  Fix this and
revise the code so that the different handling of the pattern and
the replacement string takes place in rmescapes rather than the
separate function parse_sub_pattern.

function                                             old     new   delta
rmescapes                                            227     273     +46
static.qchars                                          3       4      +1
subevalvar                                          1177    1157     -20
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/1 up/down: 47/-20)             Total: 27 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2015-05-18 09:59:14 +02:00
Ron Yorston 549deab5ab ash: move parse-time quote flag detection to run-time
Because the parser does not recursively parse parameter expansion
with respect to quotes, we can't accurately determine quote status at
parse time.  This patch works around this by moving the quote detection
to run-time where we do interpret it recursively.

Test case:
   foo=\\ echo "<${foo#[\\]}>"
Old result:
   <\>
New result:
   <>

Do not quote back slashes in parameter expansions outside quotes.

Test case:
   a=/b/c/*
   b=\\
   echo ${a%$b*}
Old result:
   /b/c/*
New result:
   /b/c/

Based on commits 880d952, 7cfd8be, 0d7d660 and a7c21a6 from
git://git.kernel.org/pub/scm/utils/dash/dash.git by Herbert Xu

function                                             old     new   delta
argstr                                              1164    1193     +29
memtodest                                            147     174     +27
subevalvar                                          1153    1177     +24
redirect                                            1279    1282      +3
dolatstr                                               5       7      +2
static.spclchars                                      10       9      -1
expandarg                                            962     960      -2
evalcase                                             273     271      -2
evalcommand                                         1204    1197      -7
rmescapes                                            236     227      -9
preglob                                               27       8     -19
evalvar                                              604     582     -22
cmdputs                                              389     334     -55
readtoken1                                          3163    3061    -102
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 5/9 up/down: 85/-219)          Total: -134 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2015-05-18 09:57:51 +02:00
Ron Yorston ad88bdee0c ash: remove arithmetic expansion collapsing at parse time
Collapsing arithmetic expansion is incorrect when the inner arithmetic
expansion is a part of a parameter expansion.

Test case:
   unset a
   echo $((3 + ${a:=$((4 + 5))}))
   echo $a
Old result:
   12
   (4 + 5)
New result:
   12
   9

Based on commit bb777a6 from git://git.kernel.org/pub/scm/utils/dash/dash.git
by Herbert Xu

function                                             old     new   delta
readtoken1                                          3180    3163     -17

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2015-05-18 09:56:16 +02:00
Ron Yorston 7e4ed267b6 ash: remove superfluous code in arithmetic mode
Based on commits 1a74845, cfc3d6a and ff13779 from
git://git.kernel.org/pub/scm/utils/dash/dash.git by Herbert Xu

function                                             old     new   delta
evalcommand                                         1197    1204      +7
localcmd                                             327     325      -2
readtoken1                                          3200    3180     -20
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/2 up/down: 7/-22)             Total: -15 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2015-05-18 09:54:43 +02:00
Ron Yorston 3df47f9cbb ash: do not expand tilde in parameter expansion within quotes
Test case:
   unset a
   echo "${a:-~root}"
Old result:
   /root
New result:
   ~root

Based on commit 170f44d from git://git.kernel.org/pub/scm/utils/dash/dash.git
by Herbert Xu

function                                             old     new   delta
evalvar                                              598     604      +6
parse_command                                       1440    1443      +3
localcmd                                             325     327      +2
readtoken1                                          3199    3200      +1
argstr                                              1180    1164     -16
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 4/1 up/down: 12/-16)             Total: -4 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2015-05-18 09:53:26 +02:00
Ron Yorston eb6b48ba74 ash: perform tilde expansion in all parameter expansion words
Previously tilde expansion was not carried out for =?#% expansion words.

Test case:
   a=~root:~root
   echo ${a#~root}
Old result:
   /root:/root
New result:
   :/root

Based on commit dd721f71 from git://git.kernel.org/pub/scm/utils/dash/dash.git
by Herbert Xu

function                                             old     new   delta
subevalvar                                          1152    1153      +1

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2015-05-18 09:51:35 +02:00
Ron Yorston d68d1fbd6c ash: code shrink around varvalue
Based on commit c989d72 from git://git.kernel.org/pub/scm/utils/dash/dash.git
by Herbert Xu

function                                             old     new   delta
strtodest                                              -      40     +40
memtodest                                            123     147     +24
parse_command                                       1443    1440      -3
readtoken1                                          3205    3199      -6
argstr                                              1203    1180     -23
varvalue                                             788     660    -128
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 1/4 up/down: 64/-160)           Total: -96 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2015-05-18 09:49:28 +02:00