[awk] awk partly string match (if column/word partly matches)

My dummy file looks like this:

C1    C2    C3    
1     a     snow   
2     b     snowman 
snow     c     sowman

I want to get line if there is string snow in $3. I can do this like this:

awk '($3=="snow" || $3=="snowman") {print}' dummy_file

But there should be more simpler way.

Maybe this will help

http://www.math.utah.edu/docs/info/gawk_5.html

awk '$3 ~ /snow|snowman/' dummy_file

Also possible by looking for substring with index() function:

awk '(index($3, "snow") != 0) {print}' dummy_file

Shorter version:

awk 'index($3, "snow")' dummy_file

GNU sed

sed '/\s*\(\S\+\s\+\)\{2\}\bsnow\(man\)\?\b/!d' file

Input:

C1    C2    C3    
1     a     snow   
2     b     snowman 
snow     c     sowman
      snow     snow     snowmanx

..output:

1     a     snow
2     b     snowman

Print lines where the third field is either snow or snowman only:

awk '$3~/^snow(man)?$/' file