How can i add my own value to this script in bash-CodePudding

How can i add my own value to this script?

echo "Choose column: "
read k
cat file.txt | awk '{print $k}'

CodePudding user response：

You could pass the column number as a variable to awk. Also, no need to use cat because awk can read files.

#!/bin/bash

echo "Choose column: "
read -r k
awk -v col="${k}" '{print $(col)}' file.txt

Sample file.txt:

col1 col2 col3
1 2 3
4 5 6
7 8 9

Output:

$ ./script 
Choose column: 
1
col1
1
4
7
$ ./script 
Choose column: 
2
col2
2
5
8
$ ./script 
Choose column: 
3
col3
3
6
9

$ ./script 
Choose column: 
4
# Note, no columns printed because there are only 3 columns