How to Use the Command `ippevepcl` (with Examples)

The ippevepcl command is a utility designed to facilitate printing specifically tailored for black-and-white HP PCL laser printers. It supports various file types, including HP PCL, PWG Raster, and Apple Raster files, making it a versatile tool for diverse printing needs. This command is part of the broader CUPS (Common UNIX Printing System) ecosystem, and it provides robust capabilities for developers and system administrators to manage printing tasks effectively.

Use Case 1: Print a File to stdout (Status and Progress Messages Sent to stderr)

Code:

ippeveps path/to/file

Motivation: This use case is incredibly useful for situations where you need to handle the output of a print job programmatically. By directing the print output to stdout, developers can capture or redirect this output for further processing, logging, or analysis. Meanwhile, status and progress messages being diverted to stderr ensures that diagnostic information can be easily separated from the actual output.

Explanation:

• ippeveps: This is the command being invoked, indicating that the file should be processed according to the expected printing standards.
• path/to/file: Specifies the path to the file intended for printing. This argument tells the command which file to process and send to the printer. The file will be read and printed as determined by the format and capabilities of the printer.

Example Output: When executing the command, the contents of the specified file are output to stdout. You might see the raw printer data appear on your console or terminal window, depending on how stdout is handled in your specific environment. Status messages indicating, for instance, “Processing” or “Completed” may appear on stderr without affecting the main data stream.

Use Case 2: Print a File from stdin to stdout

Code:

wget -O - https://examplewebsite.com/file | ippeveps

Motivation: When dealing with dynamic or remote content, such as files available via the internet, it can be advantageous to streamline the process by passing files directly from stdin into the ippeveps command. This pipeline method is particularly useful for automation scripts or batch processing tasks where direct internet access to download and print files can simplify workflow processes.

Explanation:

• wget -O - https://examplewebsite.com/file: Utilizes wget to download the file from the specified URL. The -O - option instructs wget to output the file directly to stdout rather than saving it to a file on the disk.
• | ippeveps: Pipes the output from the wget command directly into ippeveps. This allows for immediate processing of the file content as it streams, taking full advantage of the composability of Unix-like commands.

Example Output: As the file content is piped through ippeveps, the command processes and potentially sends the output to the targeted printer. The visible result is raw printer data flowing through your terminal’s stdout channel, with any informational or error messages appearing separately in stderr. This separation aids in distinguishing between successful processing and any issues encountered during execution.

Conclusion:

The ippevepcl command utility is a powerful tool for managing print jobs in Unix-like systems, especially when interfacing with HP PCL-compatible printers. The straightforward yet flexible nature of these use cases highlights how one can leverage the command for efficient and precise printing needs. Whether you’re managing files locally or dealing with content from the web, ippevepcl provides a robust solution to streamline and facilitate your print workflows effectively.