How does the '@n' line control option function in SAS?

The '@n' line control option in SAS is designed to move the input pointer to a specific column number within the current line of data being read. This feature is particularly useful when dealing with fixed-format data files, where data fields start at specific positions. By using '@n', you can precisely specify which column to read from, allowing for greater control over the data input process.

For example, if you know that a variable starts at the 10th column of the input line, using '@10' directs SAS to begin reading data from that specific position. This capability enables you to effectively manage and manipulate data that does not follow a standard delimiter-separated format, which is essential for accurate data analysis and processing in SAS.

Other options do not pertain to the functionality of '@n'. Skipping to the next record, defining column lengths, or ending the data input do not accurately characterize the purpose of the '@n' option, which specifically affects the reading position within a line rather than the overall record or variable characteristics.