column:tldr:1b662

The command printf is used to format and print text. In this case, it is used to print the string "header1\nbar\nfoobar\n".

The "|", called a pipe symbol, is used to take the output of the command on the left and pass it as input to the command on the right.

The command column is a command-line utility that formats input into columns. It takes the input received from printf and formats it into columns based on certain parameters.

In this command, --output-width ${30} specifies the desired width of the output in columns, with a value of 30. This means that the command will try to fit the input into 30 columns as best as it can.

The --fillrows option tells column to fill the rows completely before moving on to the next row. This means that if there is empty space remaining in a row, column will fill it with additional input from the next row.

Overall, this command takes the input string "header1\nbar\nfoobar\n", formats it into columns with a width of 30, and fills the rows completely with input until there is no more input left.