integer function fdds_scanf(alias, fmt, ...)
A new definition may be selected for retrieval. Multiple names, delimited by white space, may be specified by alias. If a name is specified, the "scan" dictionaries are searched. Dictionaries are scanned from bottom-to-top and right-to-left. The newest definition that matches any alias is selected. The function returns EOF, if no match is found.
The current "scan" definition is accessed, if a blank alias is specified. The value is processed, starting from the current position. The function returns EOF, if a "scan" definition is not already selected.
fdds_scanf is controlled by a format string and optional arguments. Processing begins at the current position in the definition value. Characters are matched and converted, as specified by the ANSI C standard for the stdio scanf function. The current position is advanced as the format is processed. The function returns the number of arguments converted and assigned. It returns EOF, if conversion fails prior to the first assignment.
Dictionaries may contain alias definitions. They define alternate names for "older" definitions. alias definitions are denoted by a special prefix, "alias:defn_name" or "$defn_name". The value of an alias definition is a list of alternate names.
fmt and optional arguments control the processing of definition values. The rules correspond to the scanf function in the ANSI C standard. Values should not contain "=" (unless escaped).
Format strings MUST be terminated with a null character ('\0').
The following table summarizes conversion specifiers recognized within fmt, but see the "C" manual for more detail.
fmt modifiers
char Data type h l L * I/O type
---- --------- -------------------------------- --------------------
u integer short long longlong suppress unsigned
d integer short long longlong suppress decimal
o integer short long longlong suppress octal
x integer short long longlong suppress hexadecimal
i integer short long longlong suppress dec,oct,hex
n integer short long longlong suppress (returns # characters)
c characters NA NA NA suppress (reads spaces also)
s string NA NA NA suppress (skips initial spaces)
p pointer NA NA NA suppress
e, f, g real NA double longdouble suppress
[...] character NA NA NA suppress
[^...] character NA NA NA suppress
% NA NA NA NA NA (literal "%")
fdds_scanf pads trailing blanks or truncates strings as needed
during '%c', '%s' and '%[...]' conversion.
Unlike "C", the maximum field width is not required to prevent string overflow.
! default "alpha" to 3.14, override if defined
alpha = 3.14
ier = fdds_scanf('alpha', '%f\0', alpha)
! retrieve beta, using defn alias
ier = fdds_scanf('beta BETA Beta', '%s\0', beta)
! retrieve mixed data types (string, integer, float)
ier = fdds_scanf('gamma', '%s %i %f\0', s, i, r)
! retrieve 1st & 2nd axis sizes
ier = fdds_scanf('size.axis(1)', '%i\0', nsmp)
ier = fdds_scanf('size.axis(2)', '%i\0', ntrc)
! retrieve arbitrary number of float values
ier = fdds_scanf('omega', '%f\0',omega(1))
n = 0
do while(ier.eq.1)
n = n + 1
ier = fdds_scanf(' ', '%f\0', omega(n+1))
enddo
! retrieve alias definition itself
ier = fdds_scanf('$name', ' %s\0', alias)
fdds_dict Select DDS dictionary and mode
fdds_scank Retrieve a definition
fdds_scant Retrieve a definition
fdds_scantn Retrieve a definition
fdds_scanv Retrieve a definition