## Overview

> Note:

> The PPD API was deprecated in CUPS 1.6/macOS 10.8. Please use the new Job Ticket APIs in the CUPS Programming Manual documentation. These functions will be removed in a future release of CUPS.

The CUPS PPD API provides read-only access the data in PostScript Printer Description ("PPD") files which are used for all printers with a driver. With it you can obtain the data necessary to display printer options to users, mark option choices and check for conflicting choices, and output marked choices in PostScript output. The `ppd_file_t` structure contains all of the information in a PPD file.

> Note:

> The CUPS PPD API uses the terms "option" and "choice" instead of the Adobe terms "MainKeyword" and "OptionKeyword" to refer to specific printer options and features. CUPS also treats option ("MainKeyword") and choice ("OptionKeyword") values as case-insensitive strings, so option "InputSlot" and choice "Upper" are equivalent to "inputslot" and "upper", respectively.

### Loading a PPD File

The `ppdOpenFile` function "opens" a PPD file and loads it into memory. For example, the following code opens the current printer's PPD file in a CUPS filter:

    #include <cups/ppd.h>

    ppd_file_t *ppd = ppdOpenFile(getenv("PPD"));

The return value is a pointer to a new `ppd_file_t` structure or `NULL` if the PPD file does not exist or cannot be loaded. The `ppdClose` function frees the memory used by the structure:

    #include <cups/ppd.h>

    ppd_file_t *ppd;

    ppdClose(ppd);

Once closed, pointers to the `ppd_file_t` structure and any data in it will no longer be valid.

### Options and Groups

PPD files support multiple options, which are stored in arrays of `ppd_option_t` and `ppd_choice_t` structures.

Each option in turn is associated with a group stored in a `ppd_group_t` structure. Groups can be specified in the PPD file; if an option is not associated with a group then it is put in an automatically-generated "General" group. Groups can also have sub-groups, however CUPS currently ignores sub-groups because of past abuses of this functionality.

Option choices are selected by marking them using one of three functions. The first is `ppdMarkDefaults` which selects all of the default options in the PPD file:

    #include <cups/ppd.h>

    ppd_file_t *ppd;

    ppdMarkDefaults(ppd);

The second is `ppdMarkOption` which selects a single option choice in the PPD file. For example, the following code selects the upper paper tray:

    #include <cups/ppd.h>

    ppd_file_t *ppd;

    ppdMarkOption(ppd, "InputSlot", "Upper");

The last function is `cupsMarkOptions` which selects multiple option choices in the PPD file from an array of CUPS options, mapping IPP attributes like "media" and "sides" to their corresponding PPD options. You typically use this function in a print filter with `cupsParseOptions` and `ppdMarkDefaults` to select all of the option choices needed for the job, for example:

    #include <cups/ppd.h>

    ppd_file_t *ppd = ppdOpenFile(getenv("PPD"));
    cups_option_t *options = NULL;
    int num_options = cupsParseOptions(argv[5], 0, &options);

    ppdMarkDefaults(ppd);
    cupsMarkOptions(ppd, num_options, options);
    cupsFreeOptions(num_options, options);

### Constraints

PPD files support specification of conflict conditions, called constraints, between different options. Constraints are stored in an array of `ppd_const_t` structures which specify the options and choices that conflict with each other. The `ppdConflicts` function tells you how many of the selected options are incompatible. Since constraints are normally specified in pairs, the returned value is typically an even number.

### Page Sizes

Page sizes are special options which have physical dimensions and margins associated with them. The size information is stored in `ppd_size_t` structures and is available by looking up the named size with the `ppdPageSize` function. The page size and margins are returned in units called points; there are 72 points per inch. If you pass `NULL` for the size, the currently selected size is returned:

    #include <cups/ppd.h>

    ppd_file_t *ppd;
    ppd_size_t *size = ppdPageSize(ppd, NULL);

Besides the standard page sizes listed in a PPD file, some printers support variable or custom page sizes. Custom page sizes are supported if the `variables_sizes` member of the `ppd_file_t` structure is non-zero. The `custom_min`, `custom_max`, and `custom_margins` members of the `ppd_file_t` structure define the limits of the printable area. To get the resulting media size, use a page size string of the form "Custom.widthxlength", where "width" and "length" are in points. Custom page size names can also be specified in inches ("Custom.widthxheightin"), centimeters ("Custom.widthxheightcm"), or millimeters ("Custom.widthxheightmm"):

    #include <cups/ppd.h>

    ppd_file_t *ppd;

    /* Get an 576x720 point custom page size */
    ppd_size_t *size = ppdPageSize(ppd, "Custom.576x720");

    /* Get an 8x10 inch custom page size */
    ppd_size_t *size = ppdPageSize(ppd, "Custom.8x10in");

    /* Get a 100x200 millimeter custom page size */
    ppd_size_t *size = ppdPageSize(ppd, "Custom.100x200mm");

    /* Get a 12.7x34.5 centimeter custom page size */
    ppd_size_t *size = ppdPageSize(ppd, "Custom.12.7x34.5cm");

If the PPD does not support variable page sizes, the `ppdPageSize` function will return `NULL`.

### Attributes

Every PPD file is composed of one or more attributes. Most of these attributes are used to define groups, options, choices, and page sizes, however several informational attributes may be present which you can access in your program or filter. Attributes normally look like one of the following examples in a PPD file:

    *name: "value"
    *name spec: "value"
    *name spec/text: "value"

The `ppdFindAttr` and `ppdFindNextAttr` functions find the first and next instances, respectively, of the named attribute with the given "spec" string and return a `ppd_attr_t` structure. If you provide a NULL specifier string, all attributes with the given name will be returned. For example, the following code lists all of the `Product` attributes in a PPD file:

    #include <cups/ppd.h>

    ppd_file_t *ppd;
    ppd_attr_t *attr;

    for (attr = ppdFindAttr(ppd, "Product", NULL);
         attr != NULL;
         attr = ppdFindNextAttr(ppd, "Product", NULL))
      puts(attr->value);