Use the library function fgets$()$ to get the header row.

Use splitrow$()$ to break the header row into columns and determine the correct number of columns in the input file.

Use setorder$()$ to check the arguments, and fill the output column offset table.

Use wrtrow$()$ to output the header row.

Set the rowcount to $1($you just read the header row$).$

Use fgets$()$ to get the next input row $($top of a loop$)$ until EOF.

a$.$ Count the number of rows input $($rowcount$).$

b$.$ Use splitrow$()$ to break the row into columns.e

c$.$ Use wrtrow$()$ to output the selected columns in the specified order using the output column offset table.

d$.$ Count the number of rows not output in dropcount. Rows are not output $($dropped$)$ when either splitrow$()$ or wrtrow$()$ indicates through the return value that an error has occurred.

Write a summary of operation to stderr that says how many rows were input $($rowcount$)$ and how many rows were skipped $($dropcount$)$ due to an error with the row $($wrong number of columns or a write failure$).$