DISPLAY FILES

Sys() Functions

What would a new version of VFP be without a half-dozen or more new SYS() functions? There are now 131 known SYS() functions in VFP 7. Yikes! That's as many relatively obscure numbers as some entire languages have functions!

Fortunately, IntelliSense really helps out here: When you type "SYS(", VFP displays a list of all the functions (well, not all of them; in fact, only 86 of them appear in the list), showing not only the number but also a short description for each and a longer tool tip for the selected one.

SYS() functions are an odd lot. They really have very little in common, other than they almost always return a character value (even when you'd expect a numeric one). We think they creep into the language when the VFP team can't think of a reasonable name to assign to a "real" function.

Some of these functions really should be avoided because they've been superseded with "real" functions that do the same or almost the same thing but are much more readable. For example, which would you rather see in code: SYS(2003) or CURDIR()? SYS(2001) or SET()? SYS(22) or ORDER()? In addition, some of these are just plain obsolete: They do nothing at all in VFP. There's also a whole bunch of these that return a value (or at least don't cause an error) but are completely undocumented. We suspect these are used for internal purposes or VFP system testing and aren't really intended for us to use.

The following table lists every SYS() function grouped by category.

Category

Function

Description

Get System or VFP Information

SYS(0)

Network machine information

SYS(1)

Julian system date

SYS(2)

Seconds since midnight

SYS(5)

Default drive or volume

SYS(9)

VFP serial number

SYS(10)

String from Julian day number

SYS(11)

Julian day number

SYS(16)

Executing program filename

SYS(17)

Processor in use

SYS(18)

Current control

SYS(602)

Bitmap configuration

SYS(1001)

VFP memory

SYS(1011)

Number of memory handles

SYS(1016)

User object memory in use

SYS(2011)

Current lock status

SYS(2012)

Memo field block size

SYS(2013)

System menu name string

SYS(2018)

Error message parameter

SYS(2019)

Configuration file name and location

SYS(2020)

Default disk size

SYS(2022)

Disk cluster size

SYS(2023)

Temporary path

SYS(2029)

Table type

SYS(3053)

ODBC environment handle

OOP-Related

SYS(1270)

Object location

SYS(1271)

Object's SCX file

SYS(1272)

Object hierarchy

COM-Related

SYS(2333)

ActiveX dual interface support

SYS(2334)

Automation server invocation mode

SYS(2335)

Unattended server mode

SYS(2336)

Critical section support

SYS(2339)

Call CoFreeUnusedLibraries when COM object is released

SYS(2340)

NT service support

SYS(3095)

IDispatch pointer

SYS(3096)

IDispatch object reference

SYS(3097)

Add reference to object

SYS(3098)

Release object reference

International Support

SYS(15)

Character translation

SYS(20)

Transform German text

SYS(2300)

Add or remove codepage

SYS(3004)

Return locale ID

SYS(3005)

Set locale ID

SYS(3006)

Set language and locale IDs

Perform an Action or Update a Setting

SYS(1023)

Enable help diagnostic mode

SYS(1024)

Disable help diagnostic mode

SYS(1037)

Display Page Setup dialog

SYS(1104)

Purge cached memory

SYS(1500)

Activate a menu item

SYS(2030)

Enable/disable system component debugging

SYS(2600)

Memory "peek" or "poke"

SYS(2800)

Enable/disable Accessibility support

SYS(2801)

Extend event tracking support

SYS(3050)

Set buffer memory size

SYS(3051)

Set lock retry interval

SYS(3052)

Override SET REPROCESS locking

SYS(3054)

Rushmore optimization level

SYS(3055)

Specify FOR and WHERE clause complexity

SYS(3056)

Reread Registry settings

SYS(4204)

Enable/disable Active Document debugging support

Miscellaneous

SYS(3)

"Unique" file name

SYS(2007)

Checksum value

SYS(2014)

Minimum path

SYS(2015)

Unique procedure name

Obsolete

SYS(12)

Available memory

SYS(13)

Printer status

SYS(23)

FoxPro EMS memory usage

SYS(24)

EMS memory limit

SYS(2006)

Current graphics card

SYS(2008)

Cursor shape

SYS(2009)

Swap cursor shape

SYS(2010)

CONFIG.SYS file settings

SYS(2016)

SHOW GETS WINDOW name

SYS(2017)

Display sign-on screen

SYS(2027)

Convert DOS paths to Mac notation

Superseded With "Real" Function

SYS(6)

Current printer device; use SET('PRINTER', 1)

SYS(14)

Index expression; use KEY()

SYS(21)

Controlling index number; use TAGNO()

SYS(22)

Controlling tag or index name; use ORDER()

SYS(100)

Console setting; use SET('CONSOLE')

SYS(101)

Device setting; use SET('DEVICE')

SYS(102)

Printer setting; use SET('PRINTER')

SYS(103)

Talk setting; use SET('TALK')

SYS(1269)

Property information; use PEMSTATUS()

SYS(2000)

Filename wildcard match; use ADIR()

SYS(2001)

SET command status; use SET()

SYS(2002)

Turn insertion point on or off; use SET CURSOR

SYS(2003)

Current directory; use CURDIR()

SYS(2004)

VFP start directory; use HOME()

SYS(2005)

Current resource file; use SET('RESOURCE', 1)

SYS(2021)

Filtered index expression; use FOR()

Unknown Purpose

SYS(1002)

 

SYS(1003)

 

SYS(1004)

 

SYS(1005)

 

SYS(1006)

 

SYS(1007)

 

SYS(1008)

 

SYS(1009)

 

SYS(1010)

 

SYS(1012)

 

SYS(1013)

 

SYS(1014)

 

SYS(1015)

 

SYS(1017)

 

SYS(1022)

 

SYS(1039)

 

SYS(1101)

 

SYS(1102)

 

SYS(1103)

 

SYS(1105)

 

SYS(2024)

 

SYS(2025)

 

SYS(2026)

 

SYS(2050)

 

SYS(2400)

 

SYS(3090)

 

SYS(4000)

 

SYS(4001)

 

SYS(4003)

 

SYS(4004)

 

SYS(4010)

 

SYS(4015)

 

SYS(4201)

 

Meant for Microsoft Fox Team Use

SYS(999)

Cycles through all the built-in dialogs so spelling or translation can be checked.

SYS(1018)

Returns "Hold Index Lock during TableUpdate: " followed by "On" or "Off"; pass 0 to get "Off" or 1 for "On" (the default is "On").

SYS(1020)

Turns off the diagnostic mode turned on by SYS(1021).

SYS(1021)

Starts some kind of diagnostic mode, which is turned off by SYS(1020).

SYS(1029)

Pass 0 to move the Format menu to the end, and add the Database and Record pads. Pass 1 to restore the menu. Doesn't work under all conditions.

SYS(2901)

Causes exception code C0000005 (formerly known as a General Protection Fault or GPF) if you pass 3045. This is on purpose; it allows the Fox team to test exception code handling. You may want to consider avoiding this one in your finished applications!

SYS(3070)

"Icecap profiling turned on" displays in the status bar. We're not sure what that means, but we don't want to mess with it. Doesn't work under all conditions.

SYS(3071)

"Icecap profiling turned off" displays in the status bar. See SYS(3070), directly above. Doesn't work under all conditions.


We suspect that many of the undocumented SYS() functions are there to aid the Fox team in testing and debugging. A lot of them return intriguing values, but we haven't (yet) hacked out their meanings.

See Also

Sys(0), Sys(1), Sys(10), Sys(100), Sys(1001), Sys(101), Sys(1011), Sys(1016), Sys(102), Sys(1023), Sys(1024), Sys(103), Sys(1037), Sys(11), Sys(1104), Sys(12), Sys(1269), Sys(1270), Sys(1271), Sys(1272), Sys(13), Sys(14), Sys(15), Sys(1500), Sys(16), Sys(17), Sys(18), Sys(2), Sys(20), Sys(2000), Sys(2001), Sys(2002), Sys(2003), Sys(2004), Sys(2005), Sys(2006), Sys(2007), Sys(2008), Sys(2009), Sys(2010), Sys(2011), Sys(2012), Sys(2013), Sys(2014), Sys(2015), Sys(2016), Sys(2017), Sys(2018), Sys(2019), Sys(2020), Sys(2021), Sys(2022), Sys(2023), Sys(2027), Sys(2029), Sys(2030), Sys(21), Sys(22), Sys(23), Sys(2300), Sys(2333), Sys(2334), Sys(2335), Sys(2336), Sys(2339), Sys(2340), Sys(24), Sys(2600), Sys(2800), Sys(2801), Sys(3), Sys(3004), Sys(3005), Sys(3006), Sys(3050), Sys(3051), Sys(3052), Sys(3053), Sys(3054), Sys(3055), Sys(3056), Sys(3095), Sys(3097), Sys(3098), Sys(4204), Sys(5), Sys(6), Sys(602), Sys(7), Sys(9), Sys(999)


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Copyright © 2002 by Tamar E. Granor, Ted Roche, Doug Hennig, and Della Martin. All Rights Reserved.



Hacker's Guide to Visual FoxPro 7. 0
Hackers Guide to Visual FoxPro 7.0
ISBN: 1930919220
EAN: 2147483647
Year: 2001
Pages: 899

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