Charles Levert wrote:
>[ Here is a message sent via private email,
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>
>* On Monday 2005-12-12 at 10:12:01 +0000, Pádraig Brady wrote:
>
>
>>Hi Charles,
>>
>>
>
>Hi.
>Thanks for your interest in GNU grep.
>
>
>
>
>>I notice you've been working on the grep --color code lately.
>>I've a small patch (against cvs) attached, which minimises
>>the number of "match colour start" and "match colour end"
>>sequences outputted.
>>
>>For e.g. the following will output 8 colour sequences:
>>echo "test" | grep --color=always '.'
>>With my patch there will only be 2.
>>
>>
>
>This does output less octets in the end.
>
>At issue is whether anyone currently relies on
>every individual non-empty match being "marked
>up" by an SGR_START/SGR_END pair.
>
>
Never thought of that. That could be used I
suppose by a GUI regular expression debugger
or something.
>We already elected a while back to not "mark
>up" empty matches, which are a possibility with
>patterns such as 'a*'.
>
>
Right. Probably better leave markup
to a more specialised tool?
>
>
>
>>Where this really is beneficial is for multi byte chars.
>>For e.g the following e.g. which highlights non ascii
>>characters now works correctly on my UTF8 terminal:
>>
>>echo "utf∞" | LANG=C grep --color=always -E '[^ -~]'
>>
>>
>
>Yes, but note that this is a somewhat perverse
>combination of locales (an UTF-8 one for echo
>and C for grep).
>
>
It is. I couldn't think of another way to get grep
to match non ascii data though.
It doesn't work unless LANG=C.
>>
>>p.s. I notice the end colour sequence is now ^[m rather than ^[0m
>>Is that correct?
>>
>>
>
>Yes (^[[m with no 0), in addition to being
>followed by ^[[K unless the ne boolean
>GREP_COLORS capability is specified.
>
>
cool. Hope all terminals support that.
FYI I added the "highlight today" functionality to cal
and used terminfo (if available), which I found very easy.
The cal code does the equivalent to:
tput smso ; date +%d; tput rmso
>For now, the default SGR substring remains
>'01;31' for matched text, although it as well
>might be changed to just '1;31'.
>
>
Did that in the new attached patch, since one
if its aims is to minimise output.
>The "else" code path at the top is broken by
>this change, but this would be easy to fix.
>
>
doh! Order fixed in the attached patch
>The "if (only_matching)" code path at the bottom
>doesn't need the test within MATCH_COLOR_END(),
>but it doesn't break anything.
>
>
I was a bit worried about leaving an unterminated colour span a line.
Anyway, I've also removed this from the from the attached patch.
thanks,
Pádraig.
--- grep.c.orig 2005-12-09 17:37:35.000000000 +0000
+++ grep.c 2005-12-12 14:36:42.000000000 +0000
@@ -130,8 +130,8 @@
/* The color strings used for matched text.
The user can overwrite them using the deprecated
environment variable GREP_COLOR or the new GREP_COLORS. */
-static const char *selected_match_color = "01;31"; /* bold red */
-static const char *context_match_color = "01;31"; /* bold red */
+static const char *selected_match_color = "1;31"; /* bold red */
+static const char *context_match_color = "1;31"; /* bold red */
/* Other colors. Defaults look damn good. */
static const char *filename_color = "35"; /* magenta */
@@ -788,6 +788,19 @@
const char *mid = NULL;
char *buf; /* XXX */
const char *ibeg; /* XXX */
+ int match_color_end_pending = 0;
+
+#define MATCH_COLOR_START() \
+ do { if (!match_color_end_pending) { \
+ PR_SGR_START_IF(match_color); \
+ match_color_end_pending = 1; }\
+ } while (0)
+
+#define MATCH_COLOR_END() \
+ do { if (match_color_end_pending) { \
+ PR_SGR_END_IF(match_color); \
+ match_color_end_pending = 0; }\
+ } while (0)
if (match_icase) /* XXX - None of the -i stuff should be here. */
{
@@ -839,17 +852,21 @@
cur = mid;
mid = NULL;
}
- fwrite (cur, sizeof (char), b - cur, stdout);
+ if (b - cur) {
+ MATCH_COLOR_END();
+ fwrite (cur, sizeof (char), b - cur, stdout);
+ }
}
- PR_SGR_START_IF(match_color);
+ MATCH_COLOR_START();
fwrite (b, sizeof (char), match_size, stdout);
- PR_SGR_END_IF(match_color);
- if (only_matching)
+ if (only_matching) {
fputs("\n", stdout);
+ }
}
cur = b + match_size;
}
+ MATCH_COLOR_END();
if (buf)
free(buf); /* XXX */
