sinteur@uvabick.UUCP (John Sinteur) (08/06/89)
I recently ran into a bug in HyperCard: NumtoChar does not function if you pass a zero as a parameter, that is, if you want to write a hex $00 to a disk file, you can't. Instead, you get a $20 on disk. The same goes for reading a $00. it reads a 'space' instead, so if you do a 'chartonum', a 32 results. I already told Apple about this (the AppleLink address HYPERBUG$), but I would really like to know if somebody has a workaround for this sort of thing, as the next 'bugfixing release' probably will never exist (version 2.0 is what I expect to be the next release. This bug will probably be solved, but I can't wait for that). Any ideas? -John Sinteur sinteur@uvabick adegroot@hroeur5.bitnet john sinteur, 2:512/114 @fidonet
sirkm@ssyx.ucsc.edu (Greg Anderson) (08/08/89)
In article <2332@uvabick.UUCP> sinteur@uvabick.UUCP (John Sinteur) writes: >I recently ran into a bug in HyperCard: >NumtoChar does not function if you pass a zero as a parameter, >that is, if you want to write a hex $00 to a disk file, you can't. >Instead, you get a $20 on disk. >The same goes for reading a $00. it reads a 'space' instead, so if you >do a 'chartonum', a 32 results. (stuff deleted) >This bug will probably be solved, but I can't wait for that). > >Any ideas? > >-John Sinteur >sinteur@uvabick >adegroot@hroeur5.bitnet >john sinteur, 2:512/114 @fidonet Don't wait, the 'bug' you describe will never be fixed: it's not a bug, it's a feature. HyperCard variables and fields are null-terminated; this means that the last character of any variable or field is a null (hex $00). If you were to place a null in the middle of a variable or field, HyperCard would think that it signified the end of the contents of the text; everything that followed would be truncated. HyperCard is by design a text-only system. There isn't any way to process nulls with HyperCard; you must either change your design so you do not need to process nulls (the best solution), or do all of your processing outside of HyperCard (in an XCMD, perhaps). ___\ /___ Greg Anderson ___\ /___ \ \ / / Social Sciences Computing \ \ / / \ /\/\ / University of California, Santa Cruz \ /\/\ / \/ \/ sirkm@ssyx.ucsc.edu \/ \/