grep -A10 oneliner?

piroufreek has asked for the wisdom of the Perl Monks concerning the following question:

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Re: grep -A10 oneliner? by Roy Johnson (Monsignor) on Apr 14, 2005 at 19:53 UTC
As I posted the other day: `perl -ne 'print if $.=/pattern/..10'` Update: using // instead of ?? (originally thought you only wanted the first match) Caution: Contents may have been coded under pressure.	[reply] [d/l]
Re^2: grep -A10 oneliner? by ikegami (Patriarch) on Apr 14, 2005 at 20:21 UTC
It fails in two fashions. It only displays 9 lines after, not 10, it doesn't support overlapping ranges. Read more... (618 Bytes)	[reply] [d/l] [select]
Re^3: grep -A10 oneliner? by Roy Johnson (Monsignor) on Apr 14, 2005 at 20:34 UTC
The first is trivial: set the number to be the total number of context lines you want, including the matched pattern line. The second is a little trickier: ~~`perl -ne 'print if $.=/pattern/?1:2..10'`~~ ~~[download]~~ ~~In this case, it will print 10 lines after the match.~~ Update: so tricky, in fact, that you can't do it with the range operator. So there's no point in using $.. So you just do `perl -ne 'print if$c=/pattern/?11:$c&&$c-1'` [download] or any of the other solutions here. Sigh. One that doesn't require you to add one to the number you put in: `perl -ne 'print if(/pattern/?$c=10:$c--)>0'` [download] Caution: Contents may have been coded under pressure.	[reply] [d/l] [select]
Re^4: ...in 43 chars by gam3 (Curate) on Apr 14, 2005 at 21:54 UTC
Re: grep -A10 oneliner? by Roy Johnson (Monsignor) on Apr 14, 2005 at 21:41 UTC
I think this is fully golfed, yet reasonably readable: `perl -ne 'print if/pattern/?$c=10:$c-->0'` [download] Caution: Contents may have been coded under pressure.	[reply] [d/l]
Re: grep -A10 oneliner? by Fletch (Bishop) on Apr 14, 2005 at 19:46 UTC
`perl -lne '$c=11if/pattern/;$c--,print if$c' file` [download] FORE!: Removed unneeded space between `if $c`.	[reply] [d/l] [select]
Re: grep -A10 oneliner? by ikegami (Patriarch) on Apr 14, 2005 at 19:44 UTC
How about the following: (Not golfed) `perl -ne "$i = 11 if /pattern/; if ($i) { $i--; print; }"` [download]	[reply] [d/l]
Re: grep -A10 oneliner? by dragonchild (Archbishop) on Apr 14, 2005 at 19:41 UTC
`perl -ne 'next unless /pattern/;($i++<10)?(print($_)):(last)' <filenam +e>` [download] Update: ikegami is absolutely correct. Tested version that works: `-ne 'next unless /pattern/;print scalar <> for 1..10;last' <filename>` [download] My wife's blog	[reply] [d/l] [select]
Re^2: grep -A10 oneliner? by ikegami (Patriarch) on Apr 14, 2005 at 19:47 UTC
Doesn't work. It only displays the matches. Update: The updated solution also fails. It doesn't support overlapping ranges. Read more... (669 Bytes)	[reply] [d/l] [select]
Re: grep -A10 oneliner? by tlm (Prior) on Apr 14, 2005 at 19:52 UTC
`perl -ne '(/pattern/..$x++>9)&&print'` OK, that's my best. the lowliest monk	[reply] [d/l]
Re^2: grep -A10 oneliner? by ikegami (Patriarch) on Apr 14, 2005 at 20:17 UTC
Not quite. It doesn't support overlapping ranges. Read more... (630 Bytes)	[reply] [d/l] [select]
Re: grep -A10 oneliner? by ambrus (Abbot) on Apr 14, 2005 at 19:48 UTC
That's grep -A, not grep -b. Grep -b prints byte offsets of the matches. Update: `grep -A10`, more precisely.	[reply] [d/l]
Re^2: grep -A10 oneliner? by Fletch (Bishop) on Apr 14, 2005 at 20:23 UTC
Why not both? `# grep -b -A10 pattern file perl -ne '$c=11if/pattern/;$d=$c<11?"-":":";$t\|\|=0;$c--,print"$t$d$_"i +f$c;$t=tell' file` [download] Update: This produces the same output as GNU `diff` which prints `--\n` between groups farther than the -A amount of lines apart. `perl -lne 'if(/pattern/){print"--"if!$c&&$t;$c=11};$d=$c<11?"-":":";$t +\|\|=0;$c--,print"$t$d$_"if$c;$t=tell' file` [download]	[reply] [d/l] [select]
Re: grep -A10 oneliner? by ysth (Canon) on Apr 14, 2005 at 22:21 UTC
FWIW, my entry: `perl -wne'print if /pattern/..(/pattern/&&($.=-10),$.>=0)'` [download]	[reply] [d/l]