Scan PPD files for their options. More...

Data Structures
struct	ppd_file

Macros
#define	BAD_CHAR -25

#define	LENGTH_OF_KEYWORD 45
	Length of a PPD 'main keyword'.

#define	LENGTH_OF_NAME 45
	Length of a PPD 'option keyword'.

#define	LENGTH_OF_DESCRIPTION 255
	Length of a PPD 'description' or 'translation' string.

#define	LENGTH_OF_VALUE 4096
	Length of a PPD 'value'.

Functions
static bool	is_a_line_end (int c)

static int	skip_new_line (struct ppd_file *ppd_d, int c)

static int	get_next_char (struct ppd_file *ppd_d)

static int	print_length_error (struct ppd_file ppd_d, const char name, const unsigned char *string)

static int	print_character_error (struct ppd_file ppd_d, const char name, int c)

static int	mature_end_of_file (struct ppd_file ppd_d, const char name, int c)

static int	mature_end_of_line (struct ppd_file ppd_d, const char name, int c)

static int	append_char_to_string (unsigned char *dst, size_t sz, int c)

static int	add_to_keyword (struct ppd_file *ppd_d, int c)

static int	add_to_name (struct ppd_file *ppd_d, int c)

static int	add_to_description (struct ppd_file *ppd_d, int c)

static int	add_to_value (struct ppd_file *ppd_d, int c)

static void	reset_input_strings (struct ppd_file *ppd_d)

static int	read_comment (struct ppd_file *ppd_d)

static int	read_keyword (struct ppd_file *ppd_d, int c)

static int	skip_whitespace (struct ppd_file *ppd_d, int c)

static int	read_name (struct ppd_file *ppd_d, int c)

static int	read_description (struct ppd_file *ppd_d)

static int	read_quoted_string (struct ppd_file *ppd_d, int quote)

static int	read_value (struct ppd_file *ppd_d)

static int	read_one_line (struct ppd_file *ppd_d, int c)

static int	read_ppd_file (struct caps_ppd_options_table pot, struct ppd_file ppd_d)

static int	open_ppd_file_for_read (struct ppd_file ppd_d, const char file_name)

static void	close_ppd_file (struct ppd_file *ppd_d)

int	caps_ppd_options_table_file_read (struct caps_ppd_options_table pot, const char ppd_file_name)

Detailed Description

This is a very simple scanner for PPD files. I started with different attempts to scan this kind of files. One attempt was to use FLEX to do the job. But the syntax used in PPD files is such simple and FLEX is a huge beast, so I decided to do it by myself.

Each line in a PPD file conforms to:

 *KEYWORD[ [*]NAME[/DESCRIPTION]]:[ ]VALUE

KEYWORD's encoding is ISOLatin1, allowed chars are [:alpha:][:digit:]_.-
NAME's encoding is ISOLatin1, allowed chars are [:alpha:][:digit:]_.- (and '*'!)
DESCRIPTION's encoding is UTF8, all printable chars are allowed, except ':'
VALUE's encoding is ISOLatin1, all printable chars are allowed, NL terminates VALUE, to include NL into VALUE, it must be double quoted

Refer: Adobe TechNote #5003: PostScript Printer Description File Format Specification Version 4.3

This technote defines our KEYWORD to "main keyword" and our NAME to "option keyword". This technote defines the length of each line is up to 255 chars including the newline char(s)

Some things are still to be discussed:

how long can a keyword, name, description or value be?
- from the spec: 40 characters is the maximum length for main keywords
- from the spec: 40 characters is the maximum length for option keywords, including any extensions or qualifiers separated by dots
should we limit a line to 255 chars?
- "emit an error message or not to emit an error message"?
a 'newline' can be 10 and/or 13

Todo:

Handle hex characters (e.g. "<[\t :digit:abcdefABCDEF]+>")

"Newlines may occur and should be ignored, except in translation strings, where they are illegal."

Handle "*?" keywords

Macro Definition Documentation

◆ BAD_CHAR

#define BAD_CHAR -25

Note: The value must be different from EOF

◆ LENGTH_OF_KEYWORD

#define LENGTH_OF_KEYWORD 45

LENGTH_OF_KEYWORD

How long can be a 'keyword'? -> from the spec: 40 chars, CUPS limits it to 34 chars

◆ LENGTH_OF_NAME

#define LENGTH_OF_NAME 45

LENGTH_OF_NAME

How long can be a 'name'? -> from the spec: 40 chars, CUPS limits it to 34 chars

◆ LENGTH_OF_DESCRIPTION

#define LENGTH_OF_DESCRIPTION 255

LENGTH_OF_DESCRIPTION

Todo:: How long can be a 'description'?

◆ LENGTH_OF_VALUE

#define LENGTH_OF_VALUE 4096

LENGTH_OF_VALUE

Todo:: How long can be a 'value'? -> multi line!

Function Documentation

◆ is_a_line_end()

static bool is_a_line_end ( int c )

static

Check if the character is one of the line end/line feed group

Parameters

[in] c The character to check

Return values

true	The character c is newline or carriage return
false	The character c is something

◆ skip_new_line()

static int skip_new_line	(	struct ppd_file *	ppd_d,
		int	c
	)

static

Handle all kind of newline characters

Parameters

[in,out]	ppd_d	all info about the PPD
[in]	c	current char from the stream

Returns: Correct char for the current file content

The spec forces us to handle all kind of \n and \r for newline.

\n one line
\r one line
\n\r one line
\r\n one line
\r\r two lines
\n\n two lines

Note: Inside a quoted text the newline replacement is disabled

◆ get_next_char()

static int get_next_char ( struct ppd_file * ppd_d )

static

Read the next char from any kind of source

Parameters

[in,out] ppd_d all info about the PPD

Returns: The next 8 bit unsigned character as signed int

◆ print_length_error()

static int print_length_error	(	struct ppd_file *	ppd_d,
		const char *	name,
		const unsigned char *	string
	)

static

◆ print_character_error()

static int print_character_error	(	struct ppd_file *	ppd_d,
		const char *	name,
		int	c
	)

static

◆ mature_end_of_file()

static int mature_end_of_file	(	struct ppd_file *	ppd_d,
		const char *	name,
		int	c
	)

static

◆ mature_end_of_line()

static int mature_end_of_line	(	struct ppd_file *	ppd_d,
		const char *	name,
		int	c
	)

static

◆ append_char_to_string()

static int append_char_to_string	(	unsigned char *	dst,
		size_t	sz,
		int	c
	)

static

◆ add_to_keyword()

static int add_to_keyword	(	struct ppd_file *	ppd_d,
		int	c
	)

static

◆ add_to_name()

static int add_to_name	(	struct ppd_file *	ppd_d,
		int	c
	)

static

◆ add_to_description()

static int add_to_description	(	struct ppd_file *	ppd_d,
		int	c
	)

static

◆ add_to_value()

static int add_to_value	(	struct ppd_file *	ppd_d,
		int	c
	)

static

◆ reset_input_strings()

static void reset_input_strings ( struct ppd_file * ppd_d )

static

◆ read_comment()

static int read_comment ( struct ppd_file * ppd_d )

static

Read a comment line up to its end (line terminator)

Parameters

[in,out] ppd_d all info about the PPD

Returns: the last char not part of the comment

◆ read_keyword()

static int read_keyword	(	struct ppd_file *	ppd_d,
		int	c
	)

static

Read a keyword up to its terminator

Parameters

[in,out]	ppd_d	all info about the PPD
[in]	c	The keyword's start character

Returns: The last character not part of the keyword

Delimiters are:

whitespace
colon

From the spec:

‍Main keywords can contain any printable ASCII characters within the range of decimal 33 to decimal 126 inclusive, excluding colon and slash.

Delimiters for main keywords are space, tab, colon, or newline. After the initial '*' symbol is recognized, all characters through (but not including) the next space, tab, colon, or newline character are considered part of the main keyword.

◆ skip_whitespace()

static int skip_whitespace	(	struct ppd_file *	ppd_d,
		int	c
	)

static

◆ read_name()

static int read_name	(	struct ppd_file *	ppd_d,
		int	c
	)

static

Read the 'name' component up to its terminator

Parameters

[in,out]	ppd_d	all info about the current job
	c	the first char from name

Returns: the last char not part of the name

Terminators are:

slash
colon

From the spec:

‍Option keywords may contain any printable ASCII characters within the range of decimal 33 to decimal 126 inclusive, except for the characters slash and colon, which serve as keyword delimiters. Note that space, tab, and new- line are outside this range.

An option keyword is terminated by a colon or a slash if there is a translation string

◆ read_description()

static int read_description ( struct ppd_file * ppd_d )

static

Read a description up to its terminator

Parameters

[in,out] ppd_d all info about the PPD

Returns: The last char not part of the description

Terminators are:

colon

From the spec:

‍[...] White space and slashes are allowed in the translation string. A newline encountered before the colon should be considered as an error.

◆ read_quoted_string()

static int read_quoted_string	(	struct ppd_file *	ppd_d,
		int	quote
	)

static

Read a quoted value entry

Parameters

[in,out]	ppd_d	all info about the PPD
[in]	quote	quote character to define the end of the string

Returns: Last char read or BAD_CHAR in case of a bad value string

Allowed characters for 'value' are

0x20...0x7e printable ASCII characters
0xa0...0xff FIXME??? Not 0x80...0xff???
'"' terminates the string
EOF is an failure
Todo:
Should a '\n' be part of the resulting string or be skipped?

From the spec:

‍Everything between the double quotes is treated as literal; that is, newlines and hexadecimal substrings are allowed and are placed in the output file to be passed on to the interpreter. Note that, unlike other values, a newline does not terminate an InvocationValue and a slash does not mark the beginning of a translation string.

[...] byte codes outside the range of printable 7-bit ASCII [are forbidden] <- InvocationValue

Issue: two types of double quoted values are possible: InvocationValue or QuotedValue Both handle their characters differently.

For QuotedValue the newline is not part of the resulting string. And all characters are allowed.

Todo:: Fix line counting here!

◆ read_value()

static int read_value ( struct ppd_file * ppd_d )

static

Read a non-quoted value entry

Parameters

[in,out] ppd_d all info about the PPD

Return values

value	Last char read
BAD_CHAR	In case of a bad value string

Allowed characters for value are

0x20...0x7e printable ASCII characters
0xa0...0xff FIXME???

'\n' terminates the string

◆ read_one_line()

static int read_one_line	(	struct ppd_file *	ppd_d,
		int	c
	)

static

Read in a whole line of text (e.g. all components from the line)

Parameters

[in,out]	ppd_d	all info about the PPD
[in]	c	char

Return values

value	Last char read
BAD_CHAR	In case of a bad value string

◆ read_ppd_file()

static int read_ppd_file	(	struct caps_ppd_options_table *	pot,
		struct ppd_file *	ppd_d
	)

static

Read in a whole PPD file in

Parameters

[in,out]	pot	where to add the options read
[in,out]	ppd_d	all info about the PPD

Return values

0	in case of success
BAD_CHAR	In case of a bad value string

Todo:: Count the various line terminations only once per line

◆ open_ppd_file_for_read()

static int open_ppd_file_for_read	(	struct ppd_file *	ppd_d,
		const char *	file_name
	)

static

◆ close_ppd_file()

static void close_ppd_file ( struct ppd_file * ppd_d )

static

Data Structures

Macros

Functions

Detailed Description

Macro Definition Documentation

◆ BAD_CHAR

◆ LENGTH_OF_KEYWORD

◆ LENGTH_OF_NAME

◆ LENGTH_OF_DESCRIPTION

◆ LENGTH_OF_VALUE

Function Documentation

◆ is_a_line_end()

◆ skip_new_line()

◆ get_next_char()

◆ print_length_error()

◆ print_character_error()

◆ mature_end_of_file()

◆ mature_end_of_line()

◆ append_char_to_string()

◆ add_to_keyword()

◆ add_to_name()

◆ add_to_description()

◆ add_to_value()

◆ reset_input_strings()

◆ read_comment()

◆ read_keyword()

◆ skip_whitespace()

◆ read_name()

◆ read_description()

◆ read_quoted_string()

◆ read_value()

◆ read_one_line()

◆ read_ppd_file()

◆ open_ppd_file_for_read()

◆ close_ppd_file()