1343371036.sh

# answer of http://d.hatena.ne.jp/Yamashiro0217/20120727/1343371036
## q1
cat log.txt
## q2
cut -d , -f 1,4 log.txt
## q3
grep ^server4 log.txt
## q4
wc -l < log.txt
## q5
sort -t , -k 3,3 -n log.txt | sort -t , -k 1,1 -s | head -n 5
## q6
sort -u log.txt | wc -l
## q7
cut -d , -f 3 log.txt | sort -u | wc -l
## q8   : doesn't match to question's output
cut -d , -f 1,4 log.txt | sort | uniq -c | sort -nr | head -n 1
## q9   : doesn't match to question's output
sed -e 's/server/xxx/;s/,.*//' log.txt | sort | uniq -c
## q10
cut -d , -f 3 log.txt | grep .. | sort -nu