grep

问题 I have the following (big) file with 30233088 strings: head mystringfile.txt: GAATGAACACGAAGAA GAATGAACACGAAGAC GAATGAACACGAAGAG GAATGAACACGAAGCA cat sequence.txt

问题 I have a file on this form: X/this is the first match/blabla X-this is the second match- and here we have some fluff. And I want to extract everything that appears after "X" and between the same markers. So if I have "X+match+", I want to get "match", because it appears after "X" and between the marker "+". So for the given sample file I would like to have this output: this is the first match and then this is the second match I managed to get all the content between X followed by a marker by

问题 I have a file on this form: X/this is the first match/blabla X-this is the second match- and here we have some fluff. And I want to extract everything that appears after "X" and between the same markers. So if I have "X+match+", I want to get "match", because it appears after "X" and between the marker "+". So for the given sample file I would like to have this output: this is the first match and then this is the second match I managed to get all the content between X followed by a marker by

问题 I have a file on this form: X/this is the first match/blabla X-this is the second match- and here we have some fluff. And I want to extract everything that appears after "X" and between the same markers. So if I have "X+match+", I want to get "match", because it appears after "X" and between the marker "+". So for the given sample file I would like to have this output: this is the first match and then this is the second match I managed to get all the content between X followed by a marker by

问题 Is there any difference between enclosing grep patterns in single and double quotes? grep "abc" file.txt and grep 'abc' file.txt I'm asking since there's no way I could test all possible cases on my own, and I don't want to stumble into a case that I get wrong :) 回答1: I see a difference if you have special characters : Ex : grep "foo$barbase" file.txt The shell will try to expand the variable $barbase , this is maybe not what you intended to do. If instead you type grep 'foo$barbase' file.txt

问题 I have a dictionary with words separated by line breaks. 回答1: You can just do: egrep -x '.{1,3}' myfile This will also skip blank lines, which are technically not words. Unfortunately, the above reg-ex will count apostrophes in contractions as letters as well as hyphens in hyphenated compound words. Hyphenated compound words are not a problem at such a low letter count, but I am not sure whether or not you want to count apostrophes in contractions, which are possible (e.g., I'm). You can try

问题 We can get the last git tag, which starts by a word(e.g TEST) as follow: git describe --tag --dirty --match 'TEST*' I am wondering how can I get the last tag, which starts by word1 or word2 (e.g. TEST OR RUN)? I've tried to use regex or following but it does not work: git describe --tag --dirty --match 'TEST*|RUN*' SOLUTION: We can get number of commits to HEAD and compare those numbers, the one which has less commits is the more recently. You can find its script in the answer, which I have

问题 We can get the last git tag, which starts by a word(e.g TEST) as follow: git describe --tag --dirty --match 'TEST*' I am wondering how can I get the last tag, which starts by word1 or word2 (e.g. TEST OR RUN)? I've tried to use regex or following but it does not work: git describe --tag --dirty --match 'TEST*|RUN*' SOLUTION: We can get number of commits to HEAD and compare those numbers, the one which has less commits is the more recently. You can find its script in the answer, which I have

问题 We can get the last git tag, which starts by a word(e.g TEST) as follow: git describe --tag --dirty --match 'TEST*' I am wondering how can I get the last tag, which starts by word1 or word2 (e.g. TEST OR RUN)? I've tried to use regex or following but it does not work: git describe --tag --dirty --match 'TEST*|RUN*' SOLUTION: We can get number of commits to HEAD and compare those numbers, the one which has less commits is the more recently. You can find its script in the answer, which I have

问题 We can get the last git tag, which starts by a word(e.g TEST) as follow: git describe --tag --dirty --match 'TEST*' I am wondering how can I get the last tag, which starts by word1 or word2 (e.g. TEST OR RUN)? I've tried to use regex or following but it does not work: git describe --tag --dirty --match 'TEST*|RUN*' SOLUTION: We can get number of commits to HEAD and compare those numbers, the one which has less commits is the more recently. You can find its script in the answer, which I have