threads / patch / 53545

patch, 4 partsSelectively show only blamed limes

Subject: [PATCH 0/4] Selectively show only blamed limes

## tl;dr

14 messages between May 25, 2020 and May 31, 2020. Diffs are folded; open one to read it.

replies: 13people: 3as markdown or json

Philip Oakley· May 25, 2020, 21:57 UTC · lore

While `git blame` is able to select interesting line regions of a file, it's not easy to just display blame lines since a recent date, especially for large files.

The recent discussion on CMake[1] notes the issue of ensuring any CMake scheme kept up with changes to the fairly long Makefile. This short series first clarifies the marking of 'boundary' commits outwith the revision range or time range, then adds a `--blame-only` option to supress non-blame (boundary) commit lines, with tests, and finally adds tests for the long standing `-b` option that simply blanks out the oid, but still displays the whole file.

Philip

cc: Sibi Siddharthan <sibisiddharthan.github@gmail.com> [1] https://lore.kernel.org/git/pull.614.v2.git.1589302254.gitgitgadget@gmail.com/

Philip Oakley (4):
  doc: blame: show the boundary commit '^' caret mark
  blame: add option to show only blamed commits `--blame-only`
  blame: do not show boundary commits, only those blamed
  blame: test the -b option, use blank oid for boundary commits.
 Documentation/blame-options.txt |  4 ++++
 Documentation/git-blame.txt     |  8 ++++----
 builtin/blame.c                 |  3 +++
 t/t8002-blame.sh                | 19 +++++++++++++++++++
 4 files changed, 30 insertions(+), 4 deletions(-)
-- 
2.26.2.windows.1.13.g9dddff6983
Philip Oakley· May 25, 2020, 21:57 UTC · re: Philip Oakley · lore

[PATCH 1/4] doc: blame: show the boundary commit '^' caret mark

Make the boundary commits' ^ caret findable in the documentation.
Signed-off-by: Philip Oakley <philipoakley@iee.email>
---
 Documentation/git-blame.txt | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
Show changes to Documentation/git-blame.txt +3 −3
diff --git a/Documentation/git-blame.txt b/Documentation/git-blame.txt
index 7e81541996..02f9ad6fe9 100644
--- a/Documentation/git-blame.txt
+++ b/Documentation/git-blame.txt
@@ -87,8 +87,8 @@ include::blame-options.txt[]
 
 --abbrev=<n>::
 	Instead of using the default 7+1 hexadecimal digits as the
-	abbreviated object name, use <n>+1 digits. Note that 1 column
-	is used for a caret to mark the boundary commit.
+	abbreviated commit object name, use <n>+1 digits. Note that 1 column
+	is used for a caret (`^`) to mark boundary commits.
 
 
 THE PORCELAIN FORMAT
@@ -164,7 +164,7 @@ When revision range specifiers are used to limit the annotation,
 lines that have not changed since the range boundary (either the
 commit v2.6.18 or the most recent commit that is more than 3
 weeks old in the above example) are blamed for that range
-boundary commit.
+boundary commit (preceded by `^` if shown).
 
 A particularly useful way is to see if an added file has lines
 created by copy-and-paste from existing files.  Sometimes this

-- 
2.26.2.windows.1.13.g9dddff6983
Philip Oakley· May 25, 2020, 21:57 UTC · re: Philip Oakley · lore

[PATCH 2/4] blame: add option to show only blamed commits `--blame-only`

For large files the will be many lines which are not blamed with the revision range or date period which clutter the output.

Add an option to suppress the display of boundary commits lines, not just the object id (`-b` option).

This is non-functional at this stage. The next commit will add functionality, tests, and documenation.

Signed-off-by: Philip Oakley <philipoakley@iee.email>
---
 Documentation/blame-options.txt | 4 ++++
 Documentation/git-blame.txt     | 2 +-
 builtin/blame.c                 | 2 ++
 3 files changed, 7 insertions(+), 1 deletion(-)
Show changes to 3 files +7 −1

Documentation/blame-options.txt, Documentation/git-blame.txt, builtin/blame.c

diff --git a/Documentation/blame-options.txt b/Documentation/blame-options.txt
index 5d122db6e9..b4b27033a6 100644
--- a/Documentation/blame-options.txt
+++ b/Documentation/blame-options.txt
@@ -2,6 +2,10 @@
 	Show blank SHA-1 for boundary commits.  This can also
 	be controlled via the `blame.blankboundary` config option.
 
+--blame-only::
+	Do not show any boundary commit lines created by revision range
+	specifiers. Only show blamed lines.
+
 --root::
 	Do not treat root commits as boundaries.  This can also be
 	controlled via the `blame.showRoot` config option.
diff --git a/Documentation/git-blame.txt b/Documentation/git-blame.txt
index 02f9ad6fe9..74b6344c7b 100644
--- a/Documentation/git-blame.txt
+++ b/Documentation/git-blame.txt
@@ -9,7 +9,7 @@ SYNOPSIS
 --------
 [verse]
 'git blame' [-c] [-b] [-l] [--root] [-t] [-f] [-n] [-s] [-e] [-p] [-w] [--incremental]
-	    [-L <range>] [-S <revs-file>] [-M] [-C] [-C] [-C] [--since=<date>]
+	    [-L <range>] [-S <revs-file>] [-M] [-C] [-C] [-C] [--since=<date>] [--blame-only]
 	    [--ignore-rev <rev>] [--ignore-revs-file <file>]
 	    [--progress] [--abbrev=<n>] [<rev> | --contents <file> | --reverse <rev>..<rev>]
 	    [--] <file>
diff --git a/builtin/blame.c b/builtin/blame.c
index bf1cecdf3f..b699c777c4 100644
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -45,6 +45,7 @@ static int max_score_digits;
 static int show_root;
 static int reverse;
 static int blank_boundary;
+static int blame_only;
 static int incremental;
 static int xdl_opts;
 static int abbrev = -1;
@@ -843,6 +844,7 @@ int cmd_blame(int argc, const char **argv, const char *prefix)
 	const struct option options[] = {
 		OPT_BOOL(0, "incremental", &incremental, N_("Show blame entries as we find them, incrementally")),
 		OPT_BOOL('b', NULL, &blank_boundary, N_("Show blank SHA-1 for boundary commits (Default: off)")),
+		OPT_BOOL(0, "blame-only", &blame_only, N_("Only show blamed commits (Default: off)")),
 		OPT_BOOL(0, "root", &show_root, N_("Do not treat root commits as boundaries (Default: off)")),
 		OPT_BOOL(0, "show-stats", &show_stats, N_("Show work cost statistics")),
 		OPT_BOOL(0, "progress", &show_progress, N_("Force progress reporting")),

-- 
2.26.2.windows.1.13.g9dddff6983
Philip Oakley· May 25, 2020, 21:57 UTC · re: Philip Oakley · lore

[PATCH 3/4] blame: do not show boundary commits, only those blamed

Make the option functional and add tests
Signed-off-by: Philip Oakley <philipoakley@iee.email>
---
 builtin/blame.c  | 1 +
 t/t8002-blame.sh | 7 +++++++
 2 files changed, 8 insertions(+)
Show changes to 2 files +8 −0

builtin/blame.c, t/t8002-blame.sh

diff --git a/builtin/blame.c b/builtin/blame.c
index b699c777c4..61e5a7ff44 100644
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -475,6 +475,7 @@ static void emit_other(struct blame_scoreboard *sb, struct blame_entry *ent, int
 			fputs(color, stdout);
 
 		if (suspect->commit->object.flags & UNINTERESTING) {
+			if (blame_only) continue;
 			if (blank_boundary)
 				memset(hex, ' ', length);
 			else if (!(opt & OUTPUT_ANNOTATE_COMPAT)) {
diff --git a/t/t8002-blame.sh b/t/t8002-blame.sh
index eea048e52c..d4877c7c54 100755
--- a/t/t8002-blame.sh
+++ b/t/t8002-blame.sh
@@ -122,4 +122,11 @@ test_expect_success '--exclude-promisor-objects does not BUG-crash' '
 	test_must_fail git blame --exclude-promisor-objects one
 '
 
+test_expect_success 'test --blame-only, exclude boundary commits' '
+	git blame --blame-only branch1.. -- file >actual &&
+	git blame branch1.. -- file >full &&
+	sed -e "/^\^/d" full >expected &&
+	test_cmp expected actual
+'
+
 test_done

-- 
2.26.2.windows.1.13.g9dddff6983
Philip Oakley· May 25, 2020, 21:57 UTC · re: Philip Oakley · lore

[PATCH 4/4] blame: test the -b option, use blank oid for boundary commits.

4c10a5caa7 (blame: -b (blame.blankboundary) and --root (blame.showroot), 2006-12-18) introduced the -b option. Add a test.

The sed script removes the last hex digit from boundary commit oids '^hexx msg' -> '^hex msg' until all leading hex's are gone, finally removing the boundary commit marker.

Signed-off-by: Philip Oakley <philipoakley@iee.email>
---
 t/t8002-blame.sh | 12 ++++++++++++
 1 file changed, 12 insertions(+)
Show changes to t/t8002-blame.sh +12 −0
diff --git a/t/t8002-blame.sh b/t/t8002-blame.sh
index d4877c7c54..de0f81abe9 100755
--- a/t/t8002-blame.sh
+++ b/t/t8002-blame.sh
@@ -129,4 +129,16 @@ test_expect_success 'test --blame-only, exclude boundary commits' '
 	test_cmp expected actual
 '
 
+test_expect_success 'test -b option, blank oid for boundary commits' '
+	git blame -b branch1.. -- file >actual &&
+	git blame branch1.. -- file >full &&
+	sed -e "/^\^/{
+		:loop;
+		s/^\(\^[0-9a-f]*\)[0-9a-f] \(.*\)/\1  \2/g;
+		tloop;
+		s/^\^/ /;
+	}" full >expected &&
+	test_cmp expected actual
+'
+
 test_done

-- 
2.26.2.windows.1.13.g9dddff6983
Jeff King· May 27, 2020, 07:30 UTC · re: Philip Oakley · lore

Re: [PATCH 4/4] blame: test the -b option, use blank oid for boundary commits.

On Mon, May 25, 2020 at 10:57:51PM +0100, Philip Oakley wrote:
> The sed script removes the last hex digit from boundary commit oids
> '^hexx msg' -> '^hex  msg' until all leading hex's are gone, finally
> removing the boundary commit marker.
Thanks for documenting this, as the sed was rather hard to read:
Show 9 quoted lines
> +test_expect_success 'test -b option, blank oid for boundary commits' '
> +	git blame -b branch1.. -- file >actual &&
> +	git blame branch1.. -- file >full &&
> +	sed -e "/^\^/{
> +		:loop;
> +		s/^\(\^[0-9a-f]*\)[0-9a-f] \(.*\)/\1  \2/g;
> +		tloop;
> +		s/^\^/ /;
> +	}" full >expected &&
I wonder if we can make it simpler.

In perl I'd probably just replace the whole string with the equivalent number of spaces, like:

  perl -pe 's/^\^\S+/" " x length($&)/e'

but I suppose some would consider that pretty magical, too. It might be simpler still to just avoid testing leading whitespace:

   sed 's/^\^[0-9a-f]* *//' <full >expected &&
   sed 's/^ *//' <actual >actual.stripped &&
   test_cmp expected actual.stripped
but perhaps the indentation is a useful part of what we're testing.
-Peff
Philip Oakley· May 27, 2020, 10:52 UTC · re: Jeff King · lore

Re: [PATCH 4/4] blame: test the -b option, use blank oid for boundary commits.

On 27/05/2020 08:30, Jeff King wrote:
Show 6 quoted lines
> On Mon, May 25, 2020 at 10:57:51PM +0100, Philip Oakley wrote:
>
>> The sed script removes the last hex digit from boundary commit oids
>> '^hexx msg' -> '^hex  msg' until all leading hex's are gone, finally
>> removing the boundary commit marker.
> Thanks for documenting this, as the sed was rather hard to read:
It was hard to write as well;-) lots of dead ends in the sed language.
Show 16 quoted lines
>
>> +test_expect_success 'test -b option, blank oid for boundary commits' '
>> +	git blame -b branch1.. -- file >actual &&
>> +	git blame branch1.. -- file >full &&
>> +	sed -e "/^\^/{
>> +		:loop;
>> +		s/^\(\^[0-9a-f]*\)[0-9a-f] \(.*\)/\1  \2/g;
>> +		tloop;
>> +		s/^\^/ /;
>> +	}" full >expected &&
> I wonder if we can make it simpler.
>
> In perl I'd probably just replace the whole string with the equivalent
> number of spaces, like:
>
>   perl -pe 's/^\^\S+/" " x length($&)/e'

I'm not a perl person, so I thought sed might be an easy target but ... it wasn't.

>
> but I suppose some would consider that pretty magical, too. 
I'd need to look it up!
Show 8 quoted lines
> It might be
> simpler still to just avoid testing leading whitespace:
>
>    sed 's/^\^[0-9a-f]* *//' <full >expected &&
>    sed 's/^ *//' <actual >actual.stripped &&
>    test_cmp expected actual.stripped
>
> but perhaps the indentation is a useful part of what we're testing.

The code does take care to exactly match indentation, so I felt that the indentation should be tested.

Philip
Jeff King· May 27, 2020, 07:23 UTC · re: Philip Oakley · lore

Re: [PATCH 0/4] Selectively show only blamed limes

On Mon, May 25, 2020 at 10:57:47PM +0100, Philip Oakley wrote:
> While `git blame` is able to select interesting line regions of a
> file, it's not easy to just display blame lines since a recent date,
> especially for large files.

I'm not convinced this is a useful thing to do in general. Lines don't always stand on their own, and you'd lack context for deciphering them. So a real example from "git blame -b --since=1.year.ago Makefile", for example (pardon the long lines):

  3a94cb31d52 (Johannes Schindelin        2019-07-29 13:08:16 -0700 2734)              -e 's|@@PROG@@|$(patsubst test-%,t/helper/test-%$(X),$(@F))$(patsubst git%,$(X),$(filter $(@F),$(BINDIR_PROGRAMS_NEED_X)))|' < $< > $@ && \
but in context it looks like:
              (Junio C Hamano             2019-05-19 16:46:42 +0900 2730) bin-wrappers/%: wrap-for-bin.sh
              (Junio C Hamano             2019-05-19 16:46:42 +0900 2731)         @mkdir -p bin-wrappers
              (Junio C Hamano             2019-05-19 16:46:42 +0900 2732)         $(QUIET_GEN)sed -e '1s|#!.*/sh|#!$(SHELL_PATH_SQ)|' \
              (Junio C Hamano             2019-05-19 16:46:42 +0900 2733)              -e 's|@@BUILD_DIR@@|$(shell pwd)|' \
  3a94cb31d52 (Johannes Schindelin        2019-07-29 13:08:16 -0700 2734)              -e 's|@@PROG@@|$(patsubst test-%,t/helper/test-%$(X),$(@F))$(patsubst git%,$(X),$(filter $(@F),$(BINDIR_PROGRAMS_NEED_X)))|' < $< > $@ && \
              (Junio C Hamano             2019-05-19 16:46:42 +0900 2735)         chmod +x $@

Of course there are cases where it might be useful. But you can already do:

  git blame --since=1.year.ago Makefile | grep -v ^^

I'm not totally opposed to the feature. I'm just really struggling to see how it would be generally useful. For special cases where you're just counting up lines, you'd be more likely to post-process the result anyway, at which point --line-porcelain is often easier to work with.

> Philip Oakley (4):
>   doc: blame: show the boundary commit '^' caret mark
This doc fix seems worthwhile on its own, though.
>   blame: add option to show only blamed commits `--blame-only`
>   blame: do not show boundary commits, only those blamed
If we do go this direction, these really ought to be a single commit.
>   blame: test the -b option, use blank oid for boundary commits.
This one might be worth doing independently, too.
-Peff
Philip Oakley· May 27, 2020, 10:24 UTC · re: Jeff King · lore

Re: [PATCH 0/4] Selectively show only blamed limes

Hi Peff
On 27/05/2020 08:23, Jeff King wrote:
Show 9 quoted lines
> On Mon, May 25, 2020 at 10:57:47PM +0100, Philip Oakley wrote:
>
>> While `git blame` is able to select interesting line regions of a
>> file, it's not easy to just display blame lines since a recent date,
>> especially for large files.
> I'm not convinced this is a useful thing to do in general. Lines don't
> always stand on their own, and you'd lack context for deciphering them.
> So a real example from "git blame -b --since=1.year.ago Makefile", for
> example (pardon the long lines):

My contention is that there is a lot of effort needed _beforehand_ to reach that point. We've already had to page down 2700 line to get there, and then had to carefully select the differing before and after context lines.

The use of the --blame-only (especially with broad date range --since) is to quickly narrow focus with the rather large file to the few areas of concern (probably related why the -b was introduced initially?)

Show 21 quoted lines
>
>   3a94cb31d52 (Johannes Schindelin        2019-07-29 13:08:16 -0700 2734)              -e 's|@@PROG@@|$(patsubst test-%,t/helper/test-%$(X),$(@F))$(patsubst git%,$(X),$(filter $(@F),$(BINDIR_PROGRAMS_NEED_X)))|' < $< > $@ && \
>
> but in context it looks like:
>
>               (Junio C Hamano             2019-05-19 16:46:42 +0900 2730) bin-wrappers/%: wrap-for-bin.sh
>               (Junio C Hamano             2019-05-19 16:46:42 +0900 2731)         @mkdir -p bin-wrappers
>               (Junio C Hamano             2019-05-19 16:46:42 +0900 2732)         $(QUIET_GEN)sed -e '1s|#!.*/sh|#!$(SHELL_PATH_SQ)|' \
>               (Junio C Hamano             2019-05-19 16:46:42 +0900 2733)              -e 's|@@BUILD_DIR@@|$(shell pwd)|' \
>   3a94cb31d52 (Johannes Schindelin        2019-07-29 13:08:16 -0700 2734)              -e 's|@@PROG@@|$(patsubst test-%,t/helper/test-%$(X),$(@F))$(patsubst git%,$(X),$(filter $(@F),$(BINDIR_PROGRAMS_NEED_X)))|' < $< > $@ && \
>               (Junio C Hamano             2019-05-19 16:46:42 +0900 2735)         chmod +x $@
>
> Of course there are cases where it might be useful. But you can already
> do:
>
>   git blame --since=1.year.ago Makefile | grep -v ^^
>
> I'm not totally opposed to the feature. I'm just really struggling to
> see how it would be generally useful. For special cases where you're
> just counting up lines, you'd be more likely to post-process the result
> anyway, at which point --line-porcelain is often easier to work with.

I'm also thinking that use of Git has expanded well beyond its core Linux VCS roots, so not all users are ready for the grep regex [1]. Hence the expansion of the `-b` to truly filter only the blamed commits.

Show 11 quoted lines
>
>> Philip Oakley (4):
>>   doc: blame: show the boundary commit '^' caret mark
> This doc fix seems worthwhile on its own, though.
>
>>   blame: add option to show only blamed commits `--blame-only`
>>   blame: do not show boundary commits, only those blamed
> If we do go this direction, these really ought to be a single commit.
>
>>   blame: test the -b option, use blank oid for boundary commits.
> This one might be worth doing independently, too.
OK. The final test look a while to come up with, so it ended up last.
>
> -Peff

Thanks Philip

[1] https://stackoverflow.com/a/42540014/717355 "Git Blame see changes after a certain date" (longer regex for the same effect)

Jeff King· May 28, 2020, 16:45 UTC · re: Philip Oakley · lore

Re: [PATCH 0/4] Selectively show only blamed limes

On Wed, May 27, 2020 at 11:24:54AM +0100, Philip Oakley wrote:
Show 9 quoted lines
> > I'm not convinced this is a useful thing to do in general. Lines don't
> > always stand on their own, and you'd lack context for deciphering them.
> > So a real example from "git blame -b --since=1.year.ago Makefile", for
> > example (pardon the long lines):
> 
> My contention is that there is a lot of effort needed _beforehand_ to
> reach that point. We've already had to page down 2700 line to get there,
> and then had to carefully select the differing before and after context
> lines.
I think:
  git blame -b --since=1.year.ago ... | less "+/^[^ ]"

works pretty well to get you to the right spot, with context (and then "/<enter>" within less takes you to the next line).

But that's also pretty magical.
> The use of the --blame-only (especially with broad date range --since)
> is to quickly narrow focus with the rather large file to the few areas
> of concern (probably related why the -b was introduced initially?)

Perhaps. I think when you get an out-of-context chunk, though, it's tricky to take the next step.

I'm still skeptical this will turn out to be all that useful in practice. But it really isn't much code to carry, so I don't have any real objection.

-Peff
Junio C Hamano· May 28, 2020, 18:30 UTC · re: Jeff King · lore

Re: [PATCH 0/4] Selectively show only blamed limes

Jeff King <peff@peff.net> writes:
Show 18 quoted lines
> On Wed, May 27, 2020 at 11:24:54AM +0100, Philip Oakley wrote:
>
>> > I'm not convinced this is a useful thing to do in general. Lines don't
>> > always stand on their own, and you'd lack context for deciphering them.
>> > So a real example from "git blame -b --since=1.year.ago Makefile", for
>> > example (pardon the long lines):
>> 
>> My contention is that there is a lot of effort needed _beforehand_ to
>> reach that point. We've already had to page down 2700 line to get there,
>> and then had to carefully select the differing before and after context
>> lines.
>
> I think:
>
>   git blame -b --since=1.year.ago ... | less "+/^[^ ]"
>
> works pretty well to get you to the right spot, with context (and then
> "/<enter>" within less takes you to the next line).

Yup. I think this is mostly about knowing how to use the tools that already exist. I am not interested in this new "feature", either.

Thanks.
Philip Oakley· May 30, 2020, 16:18 UTC · re: Junio C Hamano · lore

Re: [PATCH 0/4] Selectively show only blamed limes

On 28/05/2020 19:30, Junio C Hamano wrote:
Show 22 quoted lines
> Jeff King <peff@peff.net> writes:
>
>> On Wed, May 27, 2020 at 11:24:54AM +0100, Philip Oakley wrote:
>>
>>>> I'm not convinced this is a useful thing to do in general. Lines don't
>>>> always stand on their own, and you'd lack context for deciphering them.
>>>> So a real example from "git blame -b --since=1.year.ago Makefile", for
>>>> example (pardon the long lines):
>>> My contention is that there is a lot of effort needed _beforehand_ to
>>> reach that point. We've already had to page down 2700 line to get there,
>>> and then had to carefully select the differing before and after context
>>> lines.
>> I think:
>>
>>   git blame -b --since=1.year.ago ... | less "+/^[^ ]"
>>
>> works pretty well to get you to the right spot, with context (and then
>> "/<enter>" within less takes you to the next line).
> Yup.  I think this is mostly about knowing how to use the tools that
> already exist.  I am not interested in this new "feature", either.
>
> Thanks.

Is the presumption of knowing the *nix tools something that should documented, or is that an over simplification?

I'll trim this series to just the '^' documentation change and the '-b' option test (after v2.27.0)

Philip
Junio C Hamano· May 31, 2020, 16:02 UTC · re: Jeff King · lore

Re: [PATCH 0/4] Selectively show only blamed limes

Jeff King <peff@peff.net> writes:
Show 8 quoted lines
> I think:
>
>   git blame -b --since=1.year.ago ... | less "+/^[^ ]"
>
> works pretty well to get you to the right spot, with context (and then
> "/<enter>" within less takes you to the next line).
>
> But that's also pretty magical.

Instead of teaching each and every tool (like "git blame", "diff", "grep", etc.) a special trick to remove the lines from its output, it may make a lot more sense to add a feature to pagers that lets the users selectively "hide" the matching lines given a pattern. Then when viewing "git blame -b" output, you can first declare "lines that begin with a whitespace are sometimes uninteresting" and then tell your pager "now unshow uninteresting lines", "the same, but show 3 lines at the boundary of runs of uninteresting lines", "now show everything", etc.

That's another reason why I do not particularly find the proposed feature interesting.

Junio C Hamano· May 31, 2020, 16:28 UTC · re: Junio C Hamano · lore

Re: [PATCH 0/4] Selectively show only blamed limes

Junio C Hamano <gitster@pobox.com> writes:
Show 9 quoted lines
> Instead of teaching each and every tool (like "git blame", "diff",
> "grep", etc.) a special trick to remove the lines from its output,
> it may make a lot more sense to add a feature to pagers that lets
> the users selectively "hide" the matching lines given a pattern.
> Then when viewing "git blame -b" output, you can first declare
> "lines that begin with a whitespace are sometimes uninteresting" and
> then tell your pager "now unshow uninteresting lines", "the same, but
> show 3 lines at the boundary of runs of uninteresting lines", "now
> show everything", etc.

I forgot to say what I wanted to touch a bit more. Such a feature in pager is readily reusable for other types of payload. "Lines that begin with a whitespace are sometimes uninteresting" can also be used for output from "diff -u -U<largenumber>", and "lines that do not match '^[^:]*:[0-9]*:' are not interesting" can be used for output from "grep n -C". That would be a lot more sensible than tweaking each and every tool that generates output that sometimes needs to be read in full and sometimes needs to be shown with less interesting parts ellided.

← back to recent threads