How to Use the 'pic' Command (with Examples)

The pic command serves as a picture preprocessor for the groff (GNU Troff) document formatting system. It enables users to include simple line drawings in documents, which are subsequently typeset using the groff utility, a powerful typesetting engine. Designed for technical documentation and presentations, pic is commonly used in conjunction with text formatting to create cohesive documents that include both text and graphical elements seamlessly.

Use Case 1: Process Input with Pictures, Saving the Output for Future Typesetting with Groff to PostScript

Code:

pic path/to/input.pic > path/to/output.roff

Motivation:

When working on a document that requires consistent formatting and integration of graphics, preprocessing images or diagrams at the initial stage can be immensely beneficial. This command allows the user to process graphical input separately and store the output for further manipulation, making it a significant tool for professionals involved in technical writing or academic publishing. By preparing the graphical content before integrating it with text, authors can ensure a streamlined and error-free typesetting process, especially with extensive or complex documents.

Explanation:

• pic: This is the command used to process the graphical content written in a specific pic language format.
• path/to/input.pic: The file path where the input file, written in the pic language, is located. This file contains the descriptions of the images or diagrams that need to be processed.
• >: This redirects the output of the pic processing to a specified file instead of displaying it in the terminal.
• path/to/output.roff: The destination file where the processed output will be saved. This file will contain the pic preprocessed information, which can later be used by the groff system for further typesetting.

Example Output:

The command produces a path/to/output.roff file containing groff-compatible code. This file can then be used to typeset a document, converting the graphics into a format groff can handle, such as PostScript. The actual output file is textual and will not directly display the images but prepare them for the groff processing stage.

Use Case 2: Typeset Input with Pictures to PDF Using the [me] Macro Package

Code:

pic -T pdf path/to/input.pic | groff -me -T pdf > path/to/output.pdf

Motivation:

Authors often need their documents quickly converted into a presentable PDF format. This command provides a convenient way to incorporate graphics into documents while simultaneously applying the [me] macro package for formatting. The output is a polished PDF document, which is a standard format widely used for distribution, presentations, and print-ready materials. This methodology not only simplifies typesetting but ensures that both text and graphics are integrated seamlessly and formatted according to industry standards.

Explanation:

• pic: The command used to process graphical content. This acts as the first stage of the piped command.
• -T pdf: Specifies the desired output format. Here, pdf is chosen, signaling that the final output should be prepared as a PDF document.
• path/to/input.pic: The source file containing the graphics in a scriptable pic language.
• |: This pipe operator signifies that the output from the pic command should be used as input for the subsequent command, groff.
• groff: The powerful typesetting program used here to transform the processed graphic data into a comprehensive document.
• -me: Indicates the use of the [me] macro package, which provides macros commonly used for reports and technical papers, enhancing formatting capabilities.
• -T pdf: Again specifies the output format as a PDF, ensuring consistency across both handling of graphics and final document generation.
• >: Redirects the output of the groff process to a file instead of the display.
• path/to/output.pdf: The targeted output file, which will be the final PDF document that combines both graphics and formatted text.

Example Output:

The final output is an aesthetically formatted PDF document located at path/to/output.pdf. This document incorporates graphics processed from the pic input and formatted text using the [me] package, providing a ready-to-use PDF for presentations or publication.

Conclusion:

The pic command is a versatile tool that dramatically simplifies the process of integrating graphics in document formatting systems like groff. By following structured workflows, such as preprocessing graphics or directly typesetting to PDF, users can create complex documents that uniformly combine both visual and textual content. The ability to handle graphics systematically and produce professional documents in widely accepted formats like PDF ensures that pic remains a valuable asset for authors across various domains.