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72 lines
3.3 KiB
Plaintext
72 lines
3.3 KiB
Plaintext
The '''SHARED''' statement allows variables to be passed automatically to any [[SUB]] or [[FUNCTION]] procedure.
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{{PageSyntax}}
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:: DIM SHARED Qt AS STRING * 1
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* [[DIM]]ensioned variables are shared with all procedures in the program module.
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* When used with [[DIM]] in the main module, it eliminates the need to pass a parameter variable to a [[SUB]] or [[FUNCTION]].
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* Use [[COMMON SHARED]] to share a list of variable values with sub-procedures or other modules. See also: [[COMMON]]
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* SHARED ('''without [[DIM]]''') can share a list of variables inside of [[SUB]] or [[FUNCTION]] procedures with the main module only.
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:'''Note: SHARED variables in sub-procedures will not be passed to other sub-procedures, only the main module.'''
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''Example 1:'' Defining variable types with [[AS]] or type suffixes.
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{{CodeStart}} '' ''
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{{Cl|DIM}} {{Cl|SHARED}} Qt AS {{Cl|STRING}} * 1, price AS {{Cl|DOUBLE}}, ID AS {{Cl|INTEGER}}
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{{Cl|DIM}} {{Cl|SHARED}} Q$, prices#, IDs%
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{{CodeEnd}} '' ''
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''Example 2:'' The DIR$ function returns a filename or a list when more than one exist. The file spec can use a path and/or wildcards.
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{{CodeStart}} '' ''
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{{Cl|FOR...NEXT|FOR}} i = 1 {{Cl|TO}} 2
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{{Cl|LINE INPUT}} "Enter a file spec: ", spec$
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file$ = DIR$(spec$) 'use a file spec ONCE to find the last file name listed
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{{Cl|PRINT}} DIRCount%, file$, 'function can return the file count using SHARED variable
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{{Cl|DO}}
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K$ = {{Cl|INPUT$}}(1)
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file$ = DIR$("") 'use an empty string parameter to return a list of files!
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{{Cl|PRINT}} file$,
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{{Cl|LOOP}} {{Cl|UNTIL}} {{Cl|LEN}}(file$) = 0 'file list ends with an empty string
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{{Cl|NEXT}}
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{{Cl|END}}
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{{Cl|FUNCTION}} DIR$ (spec$)
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{{Cl|CONST}} TmpFile$ = "DIR$INF0.INF", ListMAX% = 500 'change maximum to suit your needs
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{{Cl|SHARED}} DIRCount% 'returns file count if desired
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{{Cl|STATIC}} Ready%, Index%, DirList$()
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{{Cl|IF}} {{Cl|NOT}} Ready% {{Cl|THEN}} {{Cl|REDIM}} DirList$(ListMax%): Ready% = -1 'DIM array first use
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{{Cl|IF}} spec$ > "" {{Cl|THEN}} 'get file names when a spec is given
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{{Cl|SHELL}} {{Cl|_HIDE}} "DIR " + spec$ + " /b > " + TmpFile$
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Index% = 0: DirList$(Index%) = "": ff% = {{Cl|FREEFILE}}
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{{Cl|OPEN}} TmpFile$ {{Cl|FOR (file statement)|FOR}} {{Cl|APPEND}} {{Cl|AS}} #ff%
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size& = {{Cl|LOF}}(ff%)
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{{Cl|CLOSE}} #ff%
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{{Cl|IF}} size& = 0 {{Cl|THEN}} {{Cl|KILL}} TmpFile$: {{Cl|EXIT FUNCTION}}
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{{Cl|OPEN}} TmpFile$ {{Cl|FOR (file statement)|FOR}} {{Cl|INPUT (file mode)|INPUT}} {{Cl|AS}} #ff%
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{{Cl|DO}} {{Cl|WHILE}} {{Cl|NOT}} {{Cl|EOF}}(ff%) {{Cl|AND (boolean)|AND}} Index% < ListMAX%
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Index% = Index% + 1
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{{Cl|LINE INPUT (file statement)|LINE INPUT}} #ff%, DirList$(Index%)
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{{Cl|LOOP}}
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DIRCount% = Index% 'SHARED variable can return the file count
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{{Cl|CLOSE}} #ff%
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{{Cl|KILL}} TmpFile$
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{{Cl|ELSE}} {{Cl|IF}} Index% > 0 {{Cl|THEN}} Index% = Index% - 1 'no spec sends next file name
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{{Cl|END IF}}
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DIR$ = DirList$(Index%)
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{{Cl|END FUNCTION}} '' ''
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{{CodeEnd}}{{small|Code by Ted Weissgerber}}
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: ''Explanation:'' The SHARED variable value ''DIRcount%'' can tell the main program how many files were found using a wildcard spec.
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''See also:''
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* [[DIM]], [[REDIM]]
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* [[COMMON]], [[COMMON SHARED]]
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{{PageNavigation}}
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