Xerox 721P87491 manual File operators and standard devices, Implementation limits

POSTSCRIPT

	Table 2-2.	Implementation limits
Quantity	Limit		Description
integer	Largest: 231-1		_
	Smallest: -231
real	Largest: 1038		Actual values are slightly less than 1038
	Smallest: -1038		and slightly more than -1038.
array	65536 or 216		Maximum length of an array
dict	65536 or 216		Maximum capacity of a dictionary (key
			value pairs)
string	262144 or 218		Maximum number of characters in a name
file	See “File operators and standard devices”		_
userdict	2000		Capacity of UserDict
operand stack	5000		Maximum depth of the operand stack
dict stack	50		Maximum depth of the dictionary stack
exec stack	250		Maximum depth of the execution stack
interpreter level	Variable		Maximum number of recursive invocation
			of the interpreter
save level	31		Maximum number of active saves
gsave level	31		Maximum number of active gsaves
path	1500		_
	See ”Path limits”
dash	65536		Maximum elements in dash pattern
VM	Approximately 4 megabytes		Maximum size of the virtual memory in
			bytes
systemdict	256		Maximum capacity of System Dict
errordict	28		Maximum capacity of Error Dict

File operators and standard devices

When “%stdin” is the filename for the file operator, DocuPrint NPS does not create a new file object. For example, the following PostScript segment uses %stdin to open a file:

(%stdin) (r) file % open a file for reading from the stdin device.

DocuPrint NPS returns the file object for %stdin created at initialization time, which is used for reading the PostScript master. Therefore, PostScript masters should avoid doing a closefile on %stdin because this action closes the file object that is used by the PostScript interpreter to read the PostScript master.

Although the use of the operator file on %stdin is common, other PostScript operators such as closefile are rarely used with the standard devices. Likewise, miscellaneous file operators such as

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