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Shell Programming and Scripting

awk explanation

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# 1  
Old 05-20-2010
awk explanation
Hello,
I have recently come across this awk program. Can some one shed some light on what is taking place.




Code:
awk '{!a[$1]++}END{for(i in a) if ( a[i] >10 ) print a[i],i }' $FILE

Best Regards,

jaysunn
# 2  
Old 05-20-2010
Hi.

It counts each occurrence of the first field of the input file and prints those, along with the count, when the value appears more than 10 times.

Code:
$ cat file1
1
2
3
2
2
2
2
2
2
2
2
2
2

$ awk '{!a[$1]++}END{for(i in a) if ( a[i] >10 ) print a[i],i }' file1
11 2

!a[$1]++ is the same as a[$1]++ in this case. for( i in a ) iterates the array a, putting the index of each element into i, and print a[i] prints the value associated with that index.
This User Gave Thanks to Scott For This Post:
jaysunn
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