Given a text file file.txt, transpose its content.

You may assume that each row has the same number of columns and each field is separated by the ' ' character.

For example, if file.txt has the following content:

name age
alice 21
ryan 30

Output the following:

name alice ryan
age 21 30

使用awk解决,使用一个数组保存每列的值，每读取一行，把每列追加到对应的列内容上。

#!/bin/bash
awk '
{
	for (i = 1; i <= NF; i++) {
		if (NR == 1) {
			result[i] = $i;
		} else {
			result[i] = result[i] " " $i
		}
	}
}
END {
	for (i = 1; result[i] != ""; i++) {
		print result[i];
	}
}' file.txt