Unix/Linux Shell Grep to cut

Question

I have a file, say 'names' that looks like this

first middle last     userid
Brian Duke Willy      willybd
...

whenever I use the following

line=`grep "willybd" /dir/names`
name=`echo $line | cut -f1-3 -d' '`
echo $name

It prints the following:

Brian Duke Willy      willybd
Brian Duke Willy

My question is, how would I get it to print just "Brian Duke Willy" without first printing the original line that I cut?

Answer 1

The usual way to do this sort of thing is:

awk '/willybd/{ print $1, $2, $3 }' /dir/names

or, to be more specific

awk '$4 ~ /willybd/ { print $1, $2, $3 }' /dir/names

or

awk '$4 == "willybd" { print $1, $2, $3 }' /dir/names

Answer 2

grep "willybd" /dir/names | cut "-d " -f1-3

剪切的默认定界符是制表符，而不是空格。

Answer 3

Unless you need the intermediate variables, you can use

grep "willybd" /dir/names | cut -f1-3 -d' '

One of the beautiful features of linux is that most commands can be used as filters: they read from stdin and write to stdout , which means you can "pipe" the output of one command into the next command. That's what the | character does. It's pronounced pipe .