Text macro substitution routines. More...

#include "ellLib.h"
#include "libComAPI.h"

Include dependency graph for macLib.h:

Classes
struct	MAC_HANDLE
	Macro substitution context, for use by macLib routines only. More...

Macros
#define	MAC_SIZE 256
	Maximum size of a macro name or value.

Functions
Core Library
The core library provides a minimal set of basic operations.
LIBCOM_API long epicsStdCall	macCreateHandle (MAC_HANDLE *handle, const char pairs[])
	Creates a new macro substitution context. More...

LIBCOM_API void epicsStdCall	macSuppressWarning (MAC_HANDLE *handle, int falseTrue)
	Disable or enable warning messages. More...

LIBCOM_API long epicsStdCall	macExpandString (MAC_HANDLE handle, const char src, char *dest, long capacity)
	Expand a string which may contain macro references. More...

LIBCOM_API long epicsStdCall	macPutValue (MAC_HANDLE handle, const char name, const char *value)
	Sets the value of a specific macro. More...

LIBCOM_API long epicsStdCall	macGetValue (MAC_HANDLE handle, const char name, char *value, long capacity)
	Returns the value of a macro. More...

LIBCOM_API long epicsStdCall	macDeleteHandle (MAC_HANDLE *handle)
	Marks a handle invalid, and frees all storage associated with it. More...

LIBCOM_API long epicsStdCall	macPushScope (MAC_HANDLE *handle)
	Marks the start of a new scoping level. More...

LIBCOM_API long epicsStdCall	macPopScope (MAC_HANDLE *handle)
	Retrieve the last pushed scope (like stack operations) More...

LIBCOM_API long epicsStdCall	macReportMacros (MAC_HANDLE *handle)
	Reports details of current definitions. More...

Utility Library
These convenience functions are intended for applications to use and provide a more convenient interface for some purposes.
LIBCOM_API long epicsStdCall	macParseDefns (MAC_HANDLE handle, const char defns, char **pairs[])
	Parse macro definitions into an array of {name, value} pairs. More...

LIBCOM_API long epicsStdCall	macInstallMacros (MAC_HANDLE handle, char pairs[])
	Install set of {name, value} pairs as definitions. More...

LIBCOM_API char *epicsStdCall	macEnvExpand (const char *str)
	Expand environment variables in a string. More...

LIBCOM_API char *epicsStdCall	macDefExpand (const char str, MAC_HANDLE macros)
	Expands macros and environment variables in a string. More...

Detailed Description

Author: William Lupton, W. M. Keck Observatory

This general purpose macro substitution library is used for all macro substitutions in EPICS Base.

Most routines return 0 (OK) on success, -1 (ERROR) on failure, or small positive values for extra info. The macGetValue() and macExpandString() routines depart from this and return information both on success / failure and on value length. Errors and warnings are reported using errlogPrintf().

Definition in file macLib.h.

Function Documentation

LIBCOM_API long epicsStdCall macCreateHandle	(	MAC_HANDLE **	handle,
		const char *	pairs[]
	)

Returns: 0 = OK; <0 = ERROR

Parameters

handle	pointer to variable to receive pointer to new macro substitution context
pairs	pointer to NULL-terminated array of {name,value} pair strings. A NULL value implies undefined; a NULL `pairs` argument implies no macros.

LIBCOM_API void epicsStdCall macSuppressWarning	(	MAC_HANDLE *	handle,
		int	falseTrue
	)

The macExpandString() routine prints warnings when it cant expand a macro. This routine can be used to silence those warnings. A non zero value will suppress the warning messages from subsequent library routines given the same handle.

Parameters

handle	opaque handle
falseTrue	0 means issue, 1 means suppress

LIBCOM_API long epicsStdCall macExpandString	(	MAC_HANDLE *	handle,
		const char *	src,
		char *	dest,
		long	capacity
	)

Returns: Returns the length of the expanded string, <0 if any macro are undefined

This routine parses the src string looking for macro references and passes any it finds to macGetValue() for translation.

Note: The return value is similar to that of macGetValue(). Its absolute value is the number of characters copied to dest. If the return value is negative, at least one undefined macro was left unexpanded.

Parameters

handle	opaque handle
src	source string
dest	destination string
capacity	capacity of destination buffer (dest)

LIBCOM_API long epicsStdCall macPutValue	(	MAC_HANDLE *	handle,
		const char *	name,
		const char *	value
	)

Returns: Returns the length of the value string.

Note: If value is NULL, all instances of name are undefined at all scoping levels (the named macro doesn't have to exist in this case). Macros referenced in value need not be defined at this point.

Parameters

handle	opaque handle
name	macro name
value	macro value

LIBCOM_API long epicsStdCall macGetValue	(	MAC_HANDLE *	handle,
		const char *	name,
		char *	value,
		long	capacity
	)

Returns: Returns the length of the value string, <0 if undefined

value will be zero-terminated if the length of the value is less than capacity. The return value is the number of characters copied to value (see below for behavior if the macro is undefined). If capacity is zero, no characters will be copied to value (which may be NULL) and the call can be used to check whether the macro is defined.

Note: Truncation of the value is not reported, applications should assume that truncation has occurred if the return value is equal to capacity.

If the macro is undefined, the macro reference will be returned in the value string (if permitted by maxlen) and the function value will be minus the number of characters copied. Note that treatment of capacity is intended to be consistent with the strncpy() routine.

If the value contains macro references, these references will be expanded recursively. This expansion will detect a direct or indirect self reference.

Macro references begin with a "$" immediately followed by either a "(" or a "{" character. The macro name comes next, and may optionally be succeeded by an "=" and a default value, which will be returned if the named macro is undefined at the moment of expansion. A reference is terminated by the matching ")" or "}" character.

Parameters

handle	opaque handle
name	macro name or reference
value	string to receive macro value or name argument if macro is undefined
capacity	capacity of destination buffer (value)

LIBCOM_API long epicsStdCall macDeleteHandle ( MAC_HANDLE * handle )

Returns: 0 = OK; <0 = ERROR

Note: Note that this does not free any strings into which macro values have been returned. Macro values are always returned into strings which were pre-allocated by the caller.

Parameters

handle opaque handle

LIBCOM_API long epicsStdCall macPushScope ( MAC_HANDLE * handle )

Returns: 0 = OK; <0 = ERROR

Marks all macro definitions added after this call as belonging to another scope. These macros will be lost on a macPopScope() call and those at the current scope will be re-instated.

Parameters

handle opaque handle

LIBCOM_API long epicsStdCall macPopScope ( MAC_HANDLE * handle )

Returns: 0 = OK; <0 = ERROR

See macPushScope()

Parameters

handle opaque handle

LIBCOM_API long epicsStdCall macReportMacros ( MAC_HANDLE * handle )

Returns: 0 = OK; <0 = ERROR This sends details of current definitions to standard output, and is intended purely for debugging purposes.

Parameters

handle opaque handle

LIBCOM_API long epicsStdCall macParseDefns	(	MAC_HANDLE *	handle,
		const char *	defns,
		char **	pairs[]
	)

Returns: Number of macros found; <0 = ERROR

This takes a set of macro definitions in "a=xxx,b=yyy" format and converts them into an array of pointers to character strings which are, in order, "first name", "first value", "second name", "second value" etc. The array is terminated with two NULL pointers and all storage is allocated contiguously so that it can be freed with a single call to free().

This routine is independent of any handle and provides a generally useful service which may be used elsewhere. Any macro references in values are not expanded at this point since the referenced macros may be defined or redefined before the macro actually has to be translated.

Shell-style escapes and quotes are supported, as are things like "A=B,B=$(C$(A)),CA=CA,CB=CB" (sets B to "CB"). White space is significant within values but ignored elsewhere (i.e. surrounding "=" and "," characters).

The function returns the number of definitions encountered, or -1 if the supplied string is invalid.

Parameters

handle	opaque handle; may be NULL if debug messages are not required.
defns	macro definitions in "a=xxx,b=yyy" format
pairs	address of variable to receive pointer to NULL-terminated array of {name, value} pair strings; all storage is allocated contiguously

LIBCOM_API long epicsStdCall macInstallMacros	(	MAC_HANDLE *	handle,
		char *	pairs[]
	)

Returns: Number of macros defined; <0 = ERROR

This takes an array of pairs as defined above and installs them as definitions by calling macPutValue(). The pairs array is terminated by a NULL pointer.

Parameters

handle	opaque handle
pairs	pointer to NULL-terminated array of {name,value} pair strings; a NULL value implies undefined; a NULL argument implies no macros

LIBCOM_API char* epicsStdCall macEnvExpand ( const char * str )

Returns: Expanded string; NULL if any undefined macros were used.

This routine expands a string which may contain macros that are environment variables. It parses the string looking for such references and passes them to macGetValue() for translation. It uses malloc() to allocate space for the expanded string and returns a pointer to this null-terminated string. It returns NULL if the source string contains any undefined references.

Parameters

str	string to be expanded

LIBCOM_API char* epicsStdCall macDefExpand	(	const char *	str,
		MAC_HANDLE *	macros
	)

Returns: Expanded string; NULL if any undefined macros were used.

This routine is similar to macEnvExpand() but allows an optional handle to be passed in that may contain additional macro definitions. These macros are appended to the set of macros from environment variables when expanding the string.

Parameters

str	string to be expanded
macros	opaque handle; may be NULL if only environment variables are to be used

Classes

Macros

Functions

Detailed Description

Function Documentation