大约有 16,000 项符合查询结果（耗时：0.0344秒） [XML]
grep a file, but show several surrounding lines?
...ch and -A num for the number of lines after the match.
grep -B 3 -A 2 foo README.txt
If you want the same number of lines before and after you can use -C num.
grep -C 3 foo README.txt
This will show 3 lines before and 3 lines after.
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How to enable mod_rewrite for Apache 2.2
... configuration has AllowOverride All in order for the .htaccess file to be read at all.
– Adam Rosenfield
Jun 23 '12 at 3:11
3
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How can I rename a field for all documents in MongoDB?
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@Steve name.last is not table.field. If you read the question, you can see that the name field holds an object.
– Marc Dingena
Oct 1 '15 at 8:31
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Creating a div element in jQuery [duplicate]
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You can read about it in the docs at api.jquery.com/jQuery/#jQuery2 (last paragraph of section)
– Gabriele Petrioli
Dec 2 '10 at 10:20
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Why would one omit the close tag?
I keep reading it is poor practice to use the PHP close tag ?> at the end of the file. The header problem seems irrelevant in the following context (and this is the only good argument so far):
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How to print matched regex pattern using awk?
...out the line, which by default is called a record, denoted by $0. At least read up the documentation.
If you only want to get print out the matched word.
awk '{for(i=1;i<=NF;i++){ if($i=="yyy"){print $i} } }' file
sha...
How do I get IntelliJ to recognize common Python modules?
...inux) as the home path.
Related discussion: http://devnet.jetbrains.net/thread/286883
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If strings are immutable in .NET, then why does Substring take O(n) time?
... I've seen this sort of code quite a bit: string contents = File.ReadAllText(filename); foreach (string line in content.Split("\n")) ... or other versions of it. I mean read an entire file, then process the various parts. That sort of code would be considerably faster and require less memo...
How to output git log with the first line only?
...%s %Cgreen(%cr) %C(bold blue)<%an>%Creset' --abbrev-commit
Further Reading.
https://coderwall.com/p/euwpig/a-better-git-log
Advanced Reading.
http://durdn.com/blog/2012/11/22/must-have-git-aliases-advanced-examples/
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Counting null and non-null values in a single query
...ount(*) FROM us WHERE a IS NOT NULL
Edited to have the full query, after reading the comments :]
SELECT COUNT(*), 'null_tally' AS narrative
FROM us
WHERE a IS NULL
UNION
SELECT COUNT(*), 'not_null_tally' AS narrative
FROM us
WHERE a IS NOT NULL;
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