searching using grep

hi how do you search for a specific field in a lis开发者_运维问答t using grep? For example in a file myfile.txt I need to search for the word apple. Thanks,

banana   nut      mango    raisin
plum     peach    cherry   orange
pear     grape    pomelo   apple
papaya   kiwi     avocado  strawberry

it depends what exactly you want as output.

'grep -w apple myfile.txt' would be a good start

which results in 'pear grape pomelo apple'

If you just want to search the 4th column for a specific word, you could first use awk to print only the 4th column, and then grep the result

awk '{print $4}' < myfile.txt | grep -w apple which results in just 'apple'

cat myfile.txt | tr -s ' ' | cut -d' ' -f4 | grep 'apple'