gpic Command in Linux
gpic is a command used in Linux to create diagrams and illustrations, especially for technical documents.
The gpic command is a part of the groff (GNU troff) document formatting system that translates descriptions of pictures into a format understood by troff or TeX, making it easier for you to include your diagrams into the text documents.
You write the picture descriptions in a procedural language, and gpic processes these descriptions to generate the final image.
Table of Contents
Here is a comprehensive guide to the options available with the gpic command −
Syntax for gpic Command
By default, the gpic command is installed on most Linux distributions. Heres the basic syntax to this command −
gpic [options] [file]
Where,
- [options] are additional parameters used to modify the behavior of the command.
- [file] is the input file that contains the picture descriptions written in the gpic language. If you dont specify a file, gpic reads from the standard input.
Options gpic Command
There are several different options that you can use with the gpic command, these are discussed in the table provided below:
| Option | Description |
|---|---|
| -C | Identifies .PS and .PE commands even if they are followed by non-whitespace characters. |
| -c | Makes gpic behave more like tpic, especially for lines starting with .ps. This option activates TeX mode and provides tpic-like line thickness handling. |
| -D | Forces the use of the \D escape sequence for all line drawing operations. |
| -n | Avoid using groff extensions to troff drawing commands; dont use zero-length lines for dots in troff mode. |
| -S | Enables a secure mode that disables shell command execution. This is useful when dealing with potentially unsafe input and is the default setting. |
| -T dev | Specifies the output device for troff; this option is typically unnecessary, as gpic output is device-independent. |
| -t | Enable TeX mode. |
| -U | Revert to unsafe mode; disable the default -S option. |
| -v | Display the version number. |
| -z | In TeX mode, draw dots by using lines that have zero length. |
Examples of gpic Command in Linux
Lets explore some examples of gpic command in Linux system:
- File Processing
- Specify an Output Device
- Generate PDF
- Run in Safe Mode
File Processing
The basic use of gpic command on Linux is to process a file containing picture descriptions. For example, to process a file named diagram.pic, you can use:
gpic diagram.pic
After you execute the above command, it will process the diagram.pic file and prepare it for further typesetting. Make sure to replace diagram.pic with the actual name of your picture description file.
Specify an Output Device
In case, you want to specify an output device, such as PostScript, you can use the -T option with the gpic command. Doing this allows you to direct the output to a specific format. For example, to specify the PostScript device, you can use:
gpic diagram.pic | groff -Tps > diagram.ps
The above command will process diagram.pic and convert it to a PostScript file named diagram.ps.
Generate PDF
With the gpic command, you can also generate a PDF from a file with picture descriptions. This is pretty useful for creating portable document formats from your picture descriptions. To do this, run:
gpic diagram.pic | groff -Tpdf > diagram.pdf
Executing the above command will process diagram.pic and convert it to a PDF file named diagram.pdf.
Run in Safe Mode
In case, you want to run the process in safe mode, you can use -S option with the gpic command, as given below:
gpic -S diagram.pic
The above command will process diagram.pic in safer mode and ensure that no shell commands are executed during processing.
Thats how you can use the gpic command on your Linux system.
Conclusion
gpic is a valuable tool within the groff formatting system that helps you seamlessly integrate diagrams and illustrations into your Linux documents.
In this tutorial, we have discussed the basic syntax, options, and examples of the gpic command. By following these examples, you will be able to learn how to effectively utilize this powerful tool for your document creation needs on your Linux system.