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Text File | 1986-05-22 | 23.5 KB | 507 lines

A. Introduction The following is the documentation for the subprogram library PASLIB01.INC which is now placed in the public domain. CAVEAT: much of this library is IBM and PC DOS specific. It has been tested on both an IBM PC-1 and an IBM PC/AT with monochrome, CGA, EGA, and Hercules boards but there are no guarantees for any other machines. Any comments or suggestions will be appreciated. Robert B. Wooster (203) 227-5588 (212) 310-5222 CIS: 72415,1602 Version 1 released 22 May 1986 B. Global Declarations 1. Constants a) IsColor a boolean set by InitMonitor depending upon whether the machines switches are set for monochrome or color. Also used in SwapMonitors, q.v. b) MaxRow, MaxCol should be self-evident c) Video attributes: LO_V: low video, HI_V high (or normal) video, RE_V: reverse video d) Special key scan codes for the use of these constants see the functions ugetc and NextField 1) cursor control keys SK_HM: Home SK_UP: up SK_PU: PgUp SK_LE: left SK_RI: right SK_EN: End SK_DN: down SK_PD: PgDn SK_IN: Ins SK_DE: Del 2) function keys SK_F1 to SK_F0 3) the Esc key : E_S_C 2. Types a) chrset b) string80: used as standard string type in most of the routines c) bigstring: for use when string80 isn't enough d) regtype: fairly standard register declaration for use in DOS function calls e) datetype: a standard date type to handle dates from 1/2/60 to 12/31/2050 f) timetype: a standard type for handling times g) scrntype & scrnptr: used in SaveScrn and RestoreScrn 3. Variables a) EquipFlag: the location of the equipment flag set by POST on IBM PCs b) MonoScrn & ColorScrn: the addresses of the monochrome and CGA screens c) KeyStat: the key status byte used by the keyboard routines d) SavedScrn: used by SaveScrn & RestoreScrn, q.v. e) SplKey: a flag used by the keyboard input routines, q.v. f) sdt: the current date according to the machine's clock; initialized in InitSys g) out: used by WhereOut, q.v. h) To_LST: see WhereOut i) EscFlag: see ugetc C. Hardware control functions 1. InitMonitor procedure a) function: sets IsColor flag according to the switch setting at EquipFlag b) syntax: InitMonitor; c) returns: nothing d) side effects: sets IsColor flag e) notes: EquipFlag is set during boot according to the hardware switch settings. In a two monitor system this means that the monochrome monitor will come up. EquipFlag can, however, be reset by some external programs such as Bob Starr's UTIL.EXE. 2. SwapMonitors procedure a) function: this is to allow two monitor systems to move back and forth between the monochrome and color monitors. b) Syntax: SwapMonitors; c) returns: nothing d) side effects: resets EquipFlag, and IsColor to their opposite monitor settings e) notes: if you return to the Turbo editor after switching monitors an odd number of times, the results can be unpredictable, i.e. your machine will more or less hang. 3. SaveScrn procedure a) function: saves current screen b) syntax: SaveScrn c) returns: nothing d) side effects: moves screen contents to savedscrn e) notes: used with restorescrn f) calls: nothing 4. RestoreScrn procedure a) function: restores saved screen b) syntax: RestoreScrn c) returns: nothing d) side effects: moves saved screen to current screen e) notes: used with savescrn f) calls: nothing 5. InitSystem procedure a) function: initialize system to standard setup b) syntax: InitSystem; c) returns: nothing d) side effects: IsColor flag and sdt are set and the standard window configuration (Sec. G) is initialized e) notes: See TEMPLATE.PAS for an example of its use f) calls: InitMonitor, InitWindows, SysDate D. Low-level Screen I/O 1. ugetc character function a) function: get a character from the keyboard without echo but with several side effects b) syntax c := ugetc; c) returns the character typed d) side effects 1) if Control-C is typed the program halts 2) if a special key, i.e. a function or cursor control key, is typed, a null character is returned and the global variable SplKey is set to that key's scan code e) notes: this is the workhorse of the input functions discussed in section D 2. putc procedure a) function: put a character on the screen with a specified attribute at the current cursor position b) syntax putc(c,b) where c is a character and b is an attribute byte. c) returns nothing d) side effects none, but note that the cursor is not moved e) notes: uses direct screen addressing 3. aputc procedure a) function: put a character c on the screen with attribute b at column x and row y b) syntax aputc(c,b,x,y) c) returns nothing d) side effects none, but note that the cursor is not moved e) notes: uses direct screen addressing E. Data I/O 1. GetUC character function a) function: get an upper case character from the keyboard if it is in OKSet, otherwise ring bell until a character in OKSet is typed b) syntax c := GetUC(default, OKSet) c) returns an upper case character d) side effects same as ugetc e) notes: useful for menu selections f) calls: ugetc 2. PutString procedure a) function: put a string on the CRT at the indicated position b) syntax PutString(s,x,y) c) returns nothing d) side effects none e) notes: writes a string80 but $V- parameter permits sending any string 3. GetString procedure a) function: get a string from the keyboard b) syntax: GetString(s1,len,x,y,s2) where s1 is the string returned as a side effect len is the maximum length of the string x,y are the screen coordinates s2 is the default string or '' c) returns: nothing d) side effects: If a string has been typed it is returned in s1. If no string typed before a special function key or <Enter> is typed s2 is returned as s1. If a special function key is pressed the global variables are set. e) notes: The function terminates after len characters have been entered. <Esc> clears an unfinished entry and lets you start over f) calls: ugetc, PutString 4. PutInteger procedure a) function: put an integer on the screen at x,y b) syntax: PutInteger(i,x,y,len) c) returns: nothing d) side effects: none e) notes: f) calls: PutString 5. GetInteger procedure a) function: get an integer from the keyboard b) syntax: GetInteger(i1,x,y,len,min,max,i2) where i1 is the integer returned x,y are the screen coordinates len is the maximum length min is the minimum acceptable value max is the maximum acceptable value i2 is the default value c) returns: nothing d) side effects: the entered value in i2 plus the same other side effects as GetString e) notes: the NumLock is set upon entering this function and released upon exit f) calls: GetString, PutInteger 6. Format string function a) function: format a number with parentheses and commas b) syntax: s := Format(r,i,j) c) returns: s as a string of length i representing a number to j decimal places with imbedded commas and parens if negative. d) side effects: none e) notes: use for pretty-printing output f) calls: 7. PutNumber procedure a) function: put a real number on CRT at x,y with length i and j decimal places b) syntax: PutNumber(r,i,j,x,y) c) returns: nothing d) side effects: none e) notes: results are unpredictable if number has more than i digits f) calls: nothing 8. GetNumber procedure a) function: get a real number from the keyboard b) syntax: GetInteger(r1,x,y,i,j,min,max,r2) where r1 is the integer returned x,y are the screen coordinates i is the maximum length j is the # of decimals min is the minimum acceptable value max is the maximum acceptable value r2 is the default value c) returns: nothing d) side effects: the entered value in r1 plus the same other side effects as GetString e) notes: the NumLock is set upon entering this function and released upon exit f) calls: GetString, PutNumber 9. PutDate procedure a) function: put a date on the CRT in the form mm/dd/yy b) syntax: PutDate(date,x,y); c) returns: nothing d) side effects: none e) notes: f) calls: 10. GetDate procedure a) function: get a legal date form the keyboard b) syntax: GetDate(date1,x,y,date2) where: date1 is the date returned x,y are the screen coordinates date2 is the default date c) returns: nothing d) side effects: date entered in date1 e) notes: NumLock is set upon entering this procedure and cleared upon exit. ANY character may be used as a delimiter If no year is given the current year is assumed Dates must be between 1/1/1960 and 12/31/2059, the appropriate century is assumed. f) calls: GetString 11. Heading procedure a) function: put a string on the heading line b) syntax: Heading(string) c) returns: nothing d) side effects: prints a message centered on line 1 e) notes: see above f) calls: MainWdo, aputc 12. Wait procedure a) function: wait for any key to be pressed b) syntax: Wait; c) returns: nothing d) side effects: none e) notes: prints "Press any key to continue" on the message line and waits for it. An improvement over REPEAT UNTIL KeyPressed because it throws away the key that was pressed. f) calls: HelpWdo, MainWdo 13. ShowHelp procedure a) function: Display a message on the message line b) syntax: ShowHelp(string) c) returns: nothing d) side effects: none e) notes: Use for explanatory messages f) calls: HelpWdo, MAinWdo 14. Prompt character function a) function: a variation on the UCSD standard prompt such as "C)ompile, E)dit, F)ile, R)un ?" b) syntax: c := Prompt(string, default); c) returns: character c d) side effects: none e) notes: any capitalized character in string is a valid response. f) calls: HelpWdo, MainWdo, GetUC F. Date Manipulation 1. Jul integer function a) function: calculate pseudo-Julian number from date b) syntax: i := Jul(date) c) returns: returns pseudo-Julian as an integer d) side effects: none e) notes: the algorithm first calculates the true Julian number as a real and then subtracts the Julian number for 1/1/60. This insures that the number will be an integer over the range of datetype. Based on a FORTRAN one-liner fount in the HP-41 user library. f) calls: None. 2. JtoD procedure a) function: convert a pseudo-Julian number to a datetype b) syntax: JtoD(i, date); c) returns: nothing d) side effects: returns date as a side effect e) notes: See Jul; this just reverses the process f) calls: none 3. J30 integer function a) function: Does the equivalent of Jul except following a 30-day month convention. b) syntax: i := J30(date) c) returns: a 30-day equivalent pseudo-Julian number d) side effects: none e) notes: See Jul. f) calls: nothing 4. LegalDate procedure a) function: checks to see if a date is a legal date, i.e., not June 31, and if it is, fixes it b) syntax: LegalDate(date); c) returns: nothing d) side effects: if date is corrected, the corrected date is returned, else the original date is returned e) notes: can be used for some input checking f) calls: nothing 5. mmdd string function a) function: converts a date to a string of the form "mm/dd" b) syntax: s := mmdd(date); c) returns: string of date in the form "mm/dd" d) side effects: none e) notes: useful for printing dates f) calls: nothing 6. mmddyy string function a) function: converts a date to a string of the form "mm/dd/yy" b) syntax: s := mmddyy(date); c) returns: string of date in the form "mm/dd/yy" d) side effects: none e) notes: useful for printing dates f) calls: nothing 7. DayofWeek integer function a) function: find the day of the week from a date b) syntax: i := DayOfWeek(date); c) returns: an integer with 0 representing Monday and 6 representing Sunday d) side effects: none e) notes: used by NextBDay f) calls: Jul 8. NextBDay procedure a) function: find the next weekday after a date b) syntax: NextBDay(date1,date2) c) returns: nothing d) side effects: date2 is the next business or week day after date1 e) notes: used for some investment calculations f) calls: DayofWeek, JtoD, jul 9. AddMonths procedure a) function: add n months to a date b) syntax: AddMonths(date1,n,date2) c) returns: nothing d) side effects: date2 is n months from date1 e) notes: very useful for bond calculations but admittedly a little kludgey f) calls: nothing 10. DayCount integer function a) function: return days between two dates b) syntax: i := DayCount(date1, date2) c) returns: number of days between two dates d) side effects: none e) notes: I was doing this so often in programs I decided to make it a function. The order of the dates is irrelevant; the absolute value of the dates is returned. f) calls: Jul 11. DatesEqual boolean function a) function: test for the equality of two dates b) syntax: Boolean := DatesEqual(date1, date2); c) returns: TRUE if date1 equals Date2, false otherwise d) side effects: none e) notes: why can't Pascal test for equality of records? f) calls: nothing 12. NullDate procedure a) function: sets a date to 1/1/60 b) syntax: NullDate(date) c) returns: nothing d) side effects: date is set to 1/1/60, which may be used as a null e) notes: used to test if a date record is initialized; may also be used to force no default in GetDate f) calls: nothing G. Window Support My standard display uses the first line as a header and the last line as a message line. The active window then becomes rows 2 through 24. Both the header and the message line are in reverse video. The procedures InitWindows, MainWdo, and HelpWdo manage this 1. InitWindows procedure a) function: set up standard windows b) syntax: InitWindows c) returns: nothing d) side effects: CRT lines 1 and 25 are set to reverse video and the active window is set to 1,2;80,24 e) notes: see above f) calls: MainWdo, aputc 2. MainWdo procedure a) function: set the active window to 1,2;80,24 b) syntax: MainWdo c) returns: nothing d) side effects: sets the active window to 1,2;80,24 e) notes: see above f) calls: nothing 3. HelpWdo procedure a) function: set the active window to the message line b) syntax: HelpWdo c) returns: nothing d) side effects: sets the active window to 1,1;80,25 e) notes: sets the cursor at 1,25 f) calls: nothing 4. UseWdo procedure a) function: creates a window for i/o b) syntax: UseWdo(x,y,col,row,string); c) returns: nothing d) side effects: see notes e) notes: creates a window with the upper left corner at x,y, col wide and row high. If possible, draws a box around the window. String is inserted in the row above the window. The window is cleared. f) calls: aputc 5. CloseWdo procedure a) function: restores MainWdo after a call to UseWdo b) syntax: CloseWdo; c) returns: nothing d) side effects: none e) notes: used to cancel effect of UseWdo. It does not, however, clear the screen. To do that use the window save and restore functions. f) calls: MainWdo H. System Services 1. SysDate procedure a) function: gets the date from the system clock b) syntax: SysDate(date); c) returns: nothing d) side effects: date is initialized to whatever date the computer's clock says it is e) notes: f) calls: 2. SysTime procedure a) function: gets the time from the system clock b) syntax: SysTime(time) c) returns: nothing d) side effects: time is initialized to whatever time the computer's clock says it is e) notes: f) calls: 3. TimeStamp string function a) function: returns a string with the current date and time b) syntax: s := TimeStamp c) returns: s initialized to a string of the form "mm/dd/yy hh:mm am" d) side effects: none e) notes: useful for including in a write statement. The value returned is based on the computer's clock. f) calls: SysTime, SysDate,TimeStamp I. Miscellaneous 1. MakeBox a) function: draws a box using reverse video on the CRT b) syntax: DrawBox(x1,y1,x2,y2) c) returns: nothing d) side effects: none e) notes: draws a box from x1,y1 to x2,y2 f) calls: aputc 2. WhereOut a) function: permits user to select between CRT and printer output. b) syntax: WhereOut c) returns: nothing d) side effects: opens "out" as either LST: or CON: depending on user response e) notes: file out should be closed when finished. f) calls: HelpWdo, MainWdo 3. Page a) function: if printer selected as output sends a form feed as per standard procedure, does a Wait if CRT selected. b) syntax: Page; c) returns: nothing d) side effects: form feed or wait e) notes: Tests To_LST flag f) calls: wait