On 9/12/06, Russell McMahon wrote: > For a friend. > I have no direct involvement with the following. > Nobody is going to take your advice if you suggest buying new windows > aware applications software :-). > > 1. Dim memory assures me that MSDOS had (has) a data-path command > that would allow data to be referenced by filename without a path > specifier if it was anywhere on the data path. ie just as > > path C:\windows;c:\UTIL;C:\FOXPRO;C:\ It's normal to use an equal sign in there: path=c:\windows;c:\util;c:\foxpro;c:\ > allows programs anywhere in the directories on the path to be accessed > by name the data equivalent allowed data to be accessed similarly. Yes and no. Path is information available to the operating system (DOS) and applications. It's use is *NOT* mandatory. DOS (i.e. COMMAND.COM) will search PATH for an executable if it is not found in the current directory. However, DOS (i.e. IBMDOS.SYS / MSDOS.SYS) does *NOT* search the path when an application opens a file. So, if your program tries to open the file "MYDATA.DAT", the DOS call will try to do so from the current directory, not the current directory plus the directories specified in the PATH. The application, however is free to search the directories specified in PATH by itself (or any other directories specified in the environment. This is why many programs add statements like SET MYAPPDIR=C:\MYAPP in the AUTOEXEC.BAT file on installation). > Such a capability is extremely dangerous, and also sometimes useful. > A friend wants top do something with an olllld DOS program that may > benefit from this feature. Another fun (and useful!) command is SUBST, where a drive letter may be used to substitute for a path. i.e. SUBST Q: C:\MYAPP\DATADIR will access the directory C:\MYAPP\DATADIR whenever Q: is used. This is useful for *VERY* old programs that do not know about paths, and even some new programs that have limits on the length of a directory string (i.e. MPLAB 7.) SUBST Q: C:\PROGRAM FILES\MICROCHIP\MPLAB 7.40\MYFILES\PROJECT Bill -- Psst... Hey, you... Buddy... Want a kitten? straycatblues.petfinder.org -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist