OK, I think this will do what you’re looking for. It will look for a pattern, and extract the 5th line before each match. grep -B5 “pattern” filename | awk -F ‘\n’ ‘ln ~ /^$/ { ln = “matched”; print $1 } $1 ~ /^–$/ { ln = “” }’ basically how this works is … Read more
Grep will recurse through any directories you match with your glob pattern. (In your case, you probably do not have any directories that match the pattern “*.cpp”) You could explicitly specify them: grep -ir “xyz” *.cpp */*.cpp */*/*.cpp */*/*/*.cpp, etc. You can also use the –include option (see the example below) If you are using … Read more
I think there is a problem with grep buffering. You can try something like this: ./adb logcat | grep –line-buffered ABC > std.txt It should be the same problem for chained grep. EDIT: A similar question can be found here: Why no output is shown when using grep twice?.
If you have xargs installed on a multi-core processor, you can benefit from the following just in case someone is interested. Environment: Processor: Dual Quad-core 2.4GHz Memory: 32 GB Number of files: 584450 Total Size: ~ 35 GB Tests: 1. Find the necessary files, pipe them to xargs and tell it to execute 8 instances. … Read more
git log is generally the command to use when examining commit history. git log –grep can be used to search for regular expressions in the commit message. What you are after is git log -S which searches the commit content simply or git log -G which searches it with a regular expression: -S<string> Look for … Read more
NOTE: This always returns true. This is not the right answer to the question, even though it has been accepted…. You could always use word boundaries around the name like \< and \>, but instead let Git do the work for you: if [ `git branch –list $branch_name` ] then echo “Branch name $branch_name already … Read more
grep –byte-offset –only-matching –text foobar filename The –byte-offset option prints the offset of each matching line. The –only-matching option makes it print offset for each matching instance instead of each matching line. The –text option makes grep treat the binary file as a text file. You can shorten it to: grep -oba foobar filename It … Read more
Use the comm(1) command to compare the two files. They both need to be sorted, which you can do beforehand if they are large, or you can do it inline with bash process substitution. comm can take a combination of the flags -1, -2 and -3 indicating which file to suppress lines from (unique to … Read more
Your question is not quite clear, but you can filter out duplicate lines with uniq: sort file.txt | uniq or simply sort -u file.txt (thanks RobEarl) You can also print only repeating lines with sort file.txt | uniq -d
grep –after-context=5 –before-context=10 ‘Nov 12 2012′ yourfile.log That’ll show each line that contains your date text, as well as 10 lines of text BEFORE the line that matched, and 5 lines AFTER the line that matched.