Search alert log for error, time and occurances

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grep Linux|
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grep -A 1 -B 1 -C 1 '' 

where  -A 1 --one line after expression match
 -B 1 --one line befor expression match
 -C 1 --one line before & after expression match



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grep SunOS|
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nawk 'c-->0;$0~s{if(b)for(c=b+1;c>1;c--)print r[(NR-c+1)%b];print;c=a}b{r[NR%b]=$0}' b=2 a=4 s="string" file1



where "b" and "a" are the number of lines to print before and after string "s" in file1.