PARHASH

Syntax PARHASH (parameter)
Location PARAMS (DIY Toolkit - Vol P)

This is an addition to the normal PARUSE and PARNAM$ functions which allows you to check whether a value passed as a parameter to a SuperBASIC PROCedure or FuNction was preceded by a hash or not.

Example

The following PROCedure allows you to create a CAT command which is similar to DIR, allowing you to use the following syntaxes:

CAT #channel [,device]
CAT [#channel,] [device]

to read a directory.

If device is not specified, then a directory of the default data device is produced. If a channel is not specified, then #1 will be used. The device can be in quotes or not if you prefer. The following can therefore all be used:

CAT #2
CAT CAT flp1_
CAT #3,'win1_'
100 DEFine PROCedure CAT (ch,direct)
110   LOCal dir_ch,sepa%,hash%
112   hash%=PARHASH(ch): sepa%=PARSEPA(ch)
120   IF sepa%>0
130     file$=PARSTR$(direct,2)
140   ELSE
150     IF hash%
160       file$=DATAD$
170     ELSE
180       file$=PARSTR$(ch,1):ch=1
185       IF file$='': file$=DATAD$
187     END IF
190   END IF
200   dir_ch=FOP\_DIR(file$)
210   IF dir_ch<0: PRINT #0,'CANNOT ACCESS DIRECTORY ON ';file$:RETurn
220   CLOSE #dir_ch
230   DIR #ch,file$
250 END DEFine

NOTE 1

There is a problem with this function that prevents the above example from working under SMS - once either PARHASH or PARSEPA have been used once on a parameter, they will not work again!!

For example, try adding the following lines to the above and compare the results:

116 PRINT PARHASH(ch), PARSEPA(direct), PARNAME$(2), PARTYP(ch), PARTYPE(direct)
117 PRINT PARHASH(ch), PARSEPA(direct), PARNAME$(2), PARTYP(ch), PARTYPE(direct)
118 STOP

NOTE 2

TURBO and SuperCHARGE cannot compile programs which use PARHASH.

CROSS-REFERENCE

PARTYPE, UNSET and PARNAME$ are also added by this toolkit.