A fictitious command madeup reads lines of input from the console until the end-of-file (EOF) character is read. For each line, if the content is a valid user ID in the system then the full pathname...

Extracted text: A fictitious command madeup reads lines of input from the console until the end-of-file (EOF) character is read. For each line, if the content is a valid user ID in the system then the full pathname of the user's home directory is written to the console; if the context is not a valid user ID, an error message is written. Show how this command could be used to process a file containing zero or more user IDs (one per line), and the output saved to tow files (one for valid user output, one for error messages).