ASME's Mechanical Engineering Toolkit 1997 December

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Since I've downloaded so much useful software from this bulletin board, I felt inclined to contribute some. These are some DOS functions that I use quite a bit. Most of them have been tested pretty much, but they're free so no warranties. Hope someone out there gets some use from these. Tom Serface ACCESS.C -- int access() - See if a file exists and can be opened. Returns 0 (NO) 1 (YES) ANNUITY.C -- double annuity(r,i,n,y) This calculates the future value realized given a regular deposit to an annuity, nominal interest rate, number of deposits per year, and the total number of of deposits that will be made (assumes 1 deposit per period) double r = regular deposit double i = annual interest rate int n = number of deposits per year int y = number of total deposits BETWEEN.C -- int between(sm,sd,sy,m,d,y) Returns the number of days between two dates int sm = Start Month int sd = Start Day int sy = Start Year int m = End Month int d = End Day int y = End Year BREAK.A -- int GetBreak() - Get Current Setting of the DOS Break Command Returns: 0=Off 1=On void SetBreak(breakval) - Set the Dos Break Command Where: int BreakVal = 0 for OFF 1 for ON CENTER.C -- void center(s2,s1,ncols) - Center a String into Another String Where: char *s1 = the string to center char *s2 = the destination string int ncols = the number of columns s2 must be at least ncols wide or memory problems occur CHDIR.A -- int ChDir(directory) - Change Directory Returns: 0=changed directory successfully 3=not a good path in str 5=could not change directory Where: char *directory = String with path name COPY.C -- int copy(from,to) - copy file named FROM to file named TO. Returns: 0=error 1=worked Where: char *from = file to copy char *to = new name of a file to create If a file named TO exists, it is deleted prior to copy. CRC.C -- There are two kinds of checksums that can be used. The first is simply the sum of the bytes without paying attention to carry. This will work most of the time, and is 1 byte per packet faster, but the second type CRC is a lot more reliable. The CRC is two bytes and is calculated as a polynomial. The algorithm is described in Andrew S. Tanenbaum's book "Computer Networks" and will detect single and double bit errors all errors with an odd number of bits, all burst errors 16 bits or less, 99.997% of 17 bit burst errors, and 99.998% or 18 bit and longer bursts. short crc(string,len) - Calculate 2 byte CRC Returns: Calculated CRC Where: char *string = string to use for CRC calculation int len = length of the string short chksum(string,len) - Calculate 1 byte checksum without paying attention to carry. Returns: Calculated CheckSum Where: char *string = string to use for CRC calculation int len = length of the string short crcfile(fName) - Calculate 2 byte CRC for a file. Returns: Calculated CRC Where: char *fName = name of file to check This is useful for comparing 2 files to make sure that they are exactly the same. CURDSK.A -- int CurDsk() - Get Current Disk Number Returns: 0=A (Drive Number) 1=B 2=C . . DAYOFWK.C -- int dayofwk(month,day,year) - Returns the day of the week. Returns: 0=Sunday 1=Monday 2=Tuesday . . . Where: int month int day int year DAYOFYR.C -- int dayofyr(month,day,year) - Returns the day of the year. Returns: 1=Jan 1st 2=Jan 2nd . . . Where: int month int day int year DISK.A -- long DiskSize(disk,&total); Returns: Free space remaining on drive -1 if the drive is invalid Where: int disk = disk number 0=default, 1=A, 2=B, 3=C ... long *total = buffer to store total disk size EFFECTIVE.C -- double effective(p,f,n,y) Returns: This calculates the effective interest rate for an investment given the initial amount, the expected future amount, the number of compounding periods per year, and the total number of periods the investment will exist. Where: double p = principal (initial investment) double f = future value of the investment int n = number of payments per year int y = number of total payments EQUIP.A -- unsigned equip() - Get equipment status Returns: 2 byte equipment status unsighned Hdisks() - Get number of hard disks Returns: Number of Fixed Disks. EQUIPMENT.C -- int equipment(type) - See what is hooked onto the PC. Returns: number of a particular equipment type. 0 if there is and error or none of a particular type Where: int type = type of equipment to query Types are: 1 - printers 2 - game ports 3 - rs232 ports 4 - diskette drives 5 - initial video mode 0 40x25 BW with color card 2 80x25 BW with color card 7 monochrome 6 - number of fixed disks FDATE.C char *fdate(buffer); Formatted date and time (Day Month Day, Year Time am/pm) e.g., Monday May 13, 1985 8:25pm This routine should be called with a buffer that has at least 40 characters. Returns: The address of the buffer you passed thru so that you can do stuff like printf("%s",fdate(buffer)); FINDFIRST.A -- DOS 2.0 functions to find files given filespec the argument to FindFirst() is a pointer to a filespec containing d:\path\filespec and an integer permission attribute for the files to find. FindNext() simply continues and fills in the DTA area with the file matching the next pattern. In the calling program you would first call SetDta(&dataArea); and then call FindFirst(filespec,attr) finally subsequent calls to FindNext(attr) can be made. The filename and attributes can be read from dataArea. FileFind.h must be included in any subroutines using these routines. Attributes for FindFirst, FindNext, GetMod, and ChMod You can set or check with '&' e.g., (attr & F_DIRECTORY) if(attr & (F_READ_ONLY & F_HIDDEN) F_NORMAL 0x00 F_READ_ONLY 0x01 F_HIDDEN 0x02 F_SYSTEM 0x04 F_LABEL 0x08 F_DIRECTORY 0x10 F_ARCHIVE 0x20 F_ALL 0xFF struct DataArea { char dta_reserved[21]; char dta_attribute; short int dta_time; short int dta_date; long int dta_file_size; char dta_name[13]; } ; void SetDta(&DTA) - Set up DTA for Wild Card Conversions or whatever This version assumes that the Struct is in the programs DS. Where: dataArea = struct *DataArea DTA void GetDta(&segment,&offset) - Get the current DTA segment and offset Where: unsigned segment = segment of the DTA unsigned offset = offset from segment beginning void RestDta(segment,offset) - Restore a saved DTA segment and offset Where: unsigned segment = saved DTA segment unsigned offset = saved offset from segment beginning int FindFirst(filespec,attr) - Find the First File From a Wild Card Pattern Returns: 0=not found 1=found Where: char *filespec = pattern of file name to find int attr = attribute for the file F_NORMAL 0x00 F_READ_ONLY 0x01 F_HIDDEN 0x02 F_SYSTEM 0x04 F_LABEL 0x08 F_DIRECTORY 0x10 F_ARCHIVE 0x20 F_ALL 0xFF int FindNext(attr) - Find the Next File From a Wild Card Pattern Returns: 0=not found 1=found Where: int attr = attribute for the file F_NORMAL 0x00 F_READ_ONLY 0x01 F_HIDDEN 0x02 F_SYSTEM 0x04 F_LABEL 0x08 F_DIRECTORY 0x10 F_ARCHIVE 0x20 F_ALL 0xFF FV.C -- double fv(p,i,n,y) This calculates the future value that can be expected from an investment given the initial value, annual interest, number of compounding periods (e.g., months per year, and the total number of periods the investment will exist. Returns: Calculated future value Where: double p = present value double i = annual interest rate int n = number of periods per year int y = number of total periods GETDATE.A -- int GetDate(&month,&day,&year) - Get Date Information Returns: day of the week Where: int month int day int year int SetDate(month,day,year) - Set Date Information Returns: 0=worked -1=error Where: int month int day int year GETDIR.A -- int GetDir(drive,directory) - Get Current Directory Returns: 0Fh if invalid drive 0 if worked Where: int drive = disk number (0=default, 1=A, 2=B, 3=C ...) char *directory = buffer to store the directory path the buffer should be at least 85 chars GETPATH.C -- int _exec(prog,args) - exec using PATH Execs a program after finding it in PATH Returns: -1=prog not found/error -2=not a .EXE or .COM file otherwise returns the return code from prog Where: char *prog=program to execute char *args=arguments for prog int _chain(prog,args) - chain using PATH Chains to a new program after finding it in PATH Returns: -1=prog not found/error -2=not a .EXE or .COM file otherwise doesn't return Where: char *prog=program to chain char *args=arguments for prog char *GetPath(prog,path) - Get the PATH for an executable Returns: Pointer to path for the prog 0 for program not found Where: char *prog=program to find char *args=buffer to hold path for prog including prog name GETENV.C -- char *GetEnv(variable, buffer, len) Retrieves the contents of an environment variable set with the DOS command SET VAR=CONTENTS. Returns: Address of buffer 0 if variable not found Where: char *variable=environment variable to retrieve e.g., "PATH" char *buffer =holding place for environment variable should be at least 128 chars unless you know that the variable will be less int len =maximum length to copy to buffer including the NULL byte '\0' at the end of the string. e.g., GetEnv("PATH",buffer,80); or if(!GetEnv("PATH",buffer,80)) { ... } GETTIME.C -- int GetTime(&hour, &min, &sec) - Get Time Information Returns: hundreths of seconds Where: int hour int min int sec int SetTime(hour,min,sec,hundreths) - Set Time Information Returns: 0=worked -1=error Where: int hour int min int sec int hundreths HARDERR.A -- ERROR codes for hard_err are found in HARDERR.H They can be indexed with harderrs[hard_err] We read about how to do this in the Cware NewLetter and simply translated the code into assembler. void SetHardErr() - Set Up Trap for Device Errors No Returns You can use this by setting hard_err to ERROR and trying to do whatever might cause a problem. If a device error occurs, hard_err will be set to the number of the error and can be used as an index for harderrs[]. This also works well with the INTERRUPT.C functions which can be used to save and restore interrupts. INTEREST.C -- double interest(p,r,n,y) - Returns Interest Amount for a Loan This calculates the interest rate for a loan given the principal, payment, number of payments per year, and the total number of payments for the loan. Where: double p = principal double r = regular payment amount int n = number of periods per year int y = number of total periods INTERRUPT.C -- void GetInt(intnum, &segment, &offset) Get Current Setting of the an Interrupt No Returns Where: int intnum=interrupt number to retrieve (e.g., 0x24) unsigned segment=buffer for the interrupt service routine's segment unsigned offset =buffer for the interrupt service routine's offset past segment segment:offset is the vector address void SetInt(intnum, segment, offset) Set the Interrupt Service Routine address for and interrupt No Returns Where: int intnum=interrupt number to set (e.g., 0x24) unsigned segment=interrupt service routine's segment unsigned offset =interrupt service routine's offset past segment segment:offset is the vector address SetInt(0x24,_showcs(),myroutine); or SetInt(0x24,SavedSeg,SavedOffset); JUL.C -- long jul(month, day, year) - Returns the number of days since 12/31/39 Julian dates are in a decent format for comparison. Where: int month int day int year KEYIN.A -- int KeyIn() - Get a Key from the Keyboard Buffer Returns: a character if any available. 0 if no key available This function also adds 128 to function and alt keys so that the defines in ALTKEYS.H and FUNKEYS.H can be used. int KeyWait() - See if there is anything in the Keyboard Buffer but leave the character in the buffer. Returns: a character if any available 0 if no key available int KeyStatus() - See if one of the special keys is pressed. Returns: Status where: bit: 0 - Right Shift Pressed 1 - Left Shift Pressed 2 - Ctrl/Shift Pressed 3 - Alt/Shift Pressed 4 - Scroll/Lock State Toggled 5 - Numeric Lock State Toggled 6 - Caps Lock State Toggled 7 - Insert State Active Defines for the above are in KeyStatus.h RIGHT_SHIFT 0x01 LEFT_SHIFT 0x02 CTRL_SHIFT 0x04 ALT_SHIFT 0x08 SCROLL_LOCK 0x10 NUM_LOCK 0x20 CAPS_LOCK 0x40 INSERT_KEY 0x80 LASTPAY.C -- double lastpay(r,p,i,n,y) Returns: the amount of the Last Payment on a Loan Where: int r = regular payment amount int p = principal of the loan int i = annual interest rate int n = number of periods per year int y = number of total periods LOCK.C -- int Lock(offset,length) - Locks parts of files under DOS 3.1 This can be used by DOS programs that run under network environments to lock portions of a file so that multi access is not allowed. Returns: 0 if worked extended error code Where: long offset=offset in the file to start the lock long length=number of bytes in the file to lock int UnLock(offset,length) - UnLocks parts of files under DOS 3.1 This should be used to unlock portions of files that were locked using Lock(). The UnLock call must look exactly like the Lock(). Returns: 0 if worked extended error code Where: long offset=offset in the file where lock begins long length=number of bytes locked LOGDSK.A -- int LogDsk(drive) - Set Current Drive Number Returns: Number Of disk drives attached 0 if invalid drive specified Where: int drive = 0=A, 1=B, 2=C, ... When you log a drive it does not actually check to see if a diskette is in the drive until you attempt to read or write. If you want to check whether or not a diskette is in the drive do a dummy open and close and check hard_err. MEMORY.A -- long MemSize() - Get Total Memory the System Has Installed Returns: Total memory long MemAvail() - Get Total Available Memory Returns: Available Memory This memory includes that taken up by your program. In other words the total memory is that which you would have if your program was not executing. MINWITH.C -- double minwith(r,i,n,y) - Minimum Amount you need to Invest to Withdraw a Fixed Amound Every Period. This calculates the initial amount required to be able to withdraw a specified amount on a regular basis. The calculation requires the amount of the withdrawal, nominal interest rate, number of withdrawals per year, and the total number of withdrawals (assumes 1 withdrawal per period). Returns: Minimum investment Where: double r = regular withdrawal double i = annual interest rate int n = number of withdrawals per year int y = number of total withdrawals MKDIR.A -- int MkDir(directory) - Create a New Directory Returns: 0=made directory successfully 3=not a good path in str 5=could not make directory Where: char *directory = directory to create MODS.A -- int ChMod(file,attribute) - Change Attributes for a File Returns: 0=successful 2=file not found 3=path not found 4=access denied Where: char *file = file to change int attribute = attribute of the file Attributes are in FILEFIND.H and include the following: F_NORMAL 0x00 F_READ_ONLY 0x01 F_HIDDEN 0x02 F_SYSTEM 0x04 F_LABEL 0x08 F_DIRECTORY 0x10 F_ARCHIVE 0x20 F_ALL 0xFF e.g., ChMod("MYFILE",F_NORMAL|F_READ_ONLY|F_HIDDEN); int GetMod(file,&attribute) - Get Attributes for a File Returns: 0=successful 2=file not found 3=path not found 4=access denied Where: char *file = file to change int attribute = buffer to store attribute of the file Notice that attribute is an integer pointer. NOMINAL.C -- double nominal(p,f,n,y) - Nominal Interest Rate for a Loan This calculates the nominal interest rate for an investment given the initial amount, the expected future amount, the number of compounding periods per year, and the total number of periods the investment will exist. Returns: Nominal Interest Rate Where: double p = principal (initial investment) double f = future value of the investment int n = number of payments per year int y = number of total payments PAYMENT.C -- double payment(p,i,n,y) - Payment Amount for a Loan This calculates the payment required to repay a loan given the principal, interest, number of payments per year, and the number of total periods (e.g., months) the loan will exist. Returns: Payment Amount Where: double p = principal double i = interest payment rate int n = number of periods per year int y = number of total periods PRINCIPAL -- double principal(r,i,n,y) - Principal for a Loan This calculates the amount that can be borrowed on a loan given the payment, interest, number of payments per year, and the number of total periods (e.g., months) the loan will exist. Returns: Principal of the Loan Where: double r = regular payment double i = interest payment rate int n = number of periods per year int y = number of total periods PV.C -- double pv(f,i,n,y) - Present Value of a Future Sum This calculates the initial amount needed to reach a future value for an investment given the future value, annual interest, number of compounding periods per year, and the total number of periods the investment will exist. Returns: Present Value Where: double f = future value double i = annual interest rate int n = number of periods per year int y = number of total periods REBOOT.A -- void Reboot() - Performs a software reboot of the system. REGDEPOSIT.C -- double regdeposit(f,i,n,y) - Regular Deposit Needed to Reach a Future Sum. This calculates the deposit amount required to reach a desired future value given the future value, nominal interest rate, number of deposits per year, and the total number of deposits that will be made (assumes 1 deposit per period) Returns: Regular Deposit Where: double f = future value desired double i = annual interest rate int n = number of deposits per year int y = number of total deposits RESET.A -- void Reset() - Resets the disk drives and flushes all of the file buffers. RMDIR.A -- int RmDir(directory) - Remove a directory Returns: 0=made directory successfully 3=not a good path in str 5=could not make directory Where: char *directory = directory to create ROUND.C -- double round(v,s) - Rounds to Significant Decimal Figure Returns: Rounded Result of V Where: double v = value to round int s = significant places ((-) left of decimal point (+) right of the decimal point) SLEEP.C -- void sleep(seconds) - Pauses Execution of a Program for (seconds) Where: int seconds = # of seconds to wait STRINDEX.C -- char *StrIndex(t,s) - Find a String Token in a given line. Returns: 0 = string not found Address of the string in the line Where: char *t = pointer to token to find char *s = pointer to string to seach STRLOWER.C -- char *StrLower(s) - Convert a String to Lower Case Returns: The address of the buffer you passed thru so that you can do stuff like printf("%s",StrLower(s)); Where: char *s = pointer to string to convert STRUPPER.O char *StrUpper(s) - Convert a String to Upper Case Returns: The address of the buffer you passed thru so that you can do stuff like printf("%s",StrUpper(s)); Where: char *s = pointer to string to convert TERM.C -- double term(p,i,n,y) - Term of a Loan This calculates the number of periods (e.g., months) a loan will exist given the principal, interest, number of payments per year, and the payment per period for the loan. Returns: Term of the Loan Where: double p = principal of the loan double i = annual interest rate int n = number of periods per year int y = number of total periods TICKS.A -- long Ticks() - Get Clock Ticks Returns: Current Clock Tick Count. The PC clock ticks about 18.21 times per second. TIMESTAMP.A -- int GetStamp(file,&dosdate) - Get Modification Time for a File. Returns: 0=Worked 2/4=File Not Found 5=Access Denied Where: char *file = Pointer to File Name long *dosdate = Long Buffer for the Date/Time Info int SetStamp(file,dosdate) - Set the Modification Time for a File. Returns: 0=Worked 2/4=File Not Found 5=Access Denied Where: char *file = Pointer to File Name long dosdate = Long which contains the Date/Time Info File time stamps are calculated with the formula: time = hour * 2048 + minute * 32 + seconds/2 date = (year-1980) * 512 + month * 32 + day The time will be in the high order 2 bytes and the date in the lower. The Time Format is: F E D C B A 9 8 7 6 5 4 3 2 1 0 +---------------------------------+ | HOURS | MINUTES | SECS/2 | +---------------------------------+ The Date Format is: F E D C B A 9 8 7 6 5 4 3 2 1 0 +---------------------------------+ | YEAR-1980 | MONTH | DAY | +---------------------------------+ VERIFY.A -- int GetVerify() - Get the Current Setting of the DOS VERIFY Command Returns: 0=OFF 1=ON void SetVerify(VerifyVal) - Sets the Verify Flag. Where: int VerifyFlag = 0=OFF or 1=ON VERSION.A -- int DosVer() = Gets Current DOS Version. Returns: 0 if DOS version < 2 otherwise version in high byte and release in low byte. WITHDRAW.A -- double withdraw(p,i,n,y) - Amount you can Withdraw for an Investment. This calculates the amount that can be withdrawn from an investment an a regular basis given the initial amount, nominal interest rate, number of withdrawals per year, and the total number of withdrawals (assumes 1 withdrawal per period) Returns: Amount you can Withdraw Where: double p = present value double i = annual interest rate int n = number of withdrawals per year int y = number of total withdrawals ------------------------------------------------------------------------ Sample Programs: CAT.C - Similar to Unix cat command. CHMOD.C - Set attributes for DOS files. This one is similar to the Unix function of the same name. Wild Cards are supported. CP.C - Similar to Unix cp command. DATETIME.C - Displays the current date and time. MV.C - Similar to Unix mv command. POP.C - Restore the directory path saved with the PUSH.EXE command. PUSH.C - Save the current directory path and move to another. Enter the command: PUSH newdirectory <CR> to move to the new directory and save the old one. The path is saved in file \PUSH.@@@ REB.C - Reboot the Computer/REBOOT.EXE SPACE.C - Displays the current memory and disk sizes. STUFF.C - Get equipment status. TOUCH.C - Set time attributes for a file to the current clock setting. Other Stuff: CURSOR.EXE - Sets the DOS Cursor. PRT.EXE - Formatted printing routine.