Shell Programming and Scripting

[root@bt /tmp]ls -lrt inputfile
-rw-r--r-- 1 orange orange 1.1M Oct 28 16:56 inputfile
 
[root@bt /tmp]time uniq -c -w8 inputfile >/dev/null
real    0m0.216s
user    0m0.216s
sys     0m0.000s
 
[root@bt /tmp]time awk '{counts[$1]++} END {for (i in counts) {print i, counts[i]}}' inputfile >/dev/null
real    0m0.030s
user    0m0.028s
sys     0m0.004s
 
[root@bt /tmp]time awk '{print $1|"sort|uniq -c"}' inputfile >/dev/null
real    0m1.622s
user    0m1.264s
sys     0m0.312s
 
[root@bt /tmp]time perl -lane '$a{$F[0]}++}{foreach (keys %a){print "$_  $a{$_}"}' inputfile >/dev/null
real    0m0.198s
user    0m0.196s
sys     0m0.004s
 
#Winner
[root@bt /tmp]time awk '{counts[$1]++} END {for (i in counts) {print i, counts[i]}}' inputfile >/dev/null
real    0m0.030s
user    0m0.028s
sys     0m0.004s

awk '!($1 in c) {key[++key[0]]=$1}{c[$1]++} END {for (i=1;i<=key[0];i++) print key[i], c[key[i]]}' myFile

[root@bt /tmp]time awk '!($1 in c) {key[++key[0]]=$1}{c[$1]++} 
END {for (i=1;i<=key[0];i++) print key[i], c[key[i]]}' inputfile >/dev/null
real    0m0.046s
user    0m0.044s
sys     0m0.000s