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