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Text File | 1994-01-17 | 31.0 KB | 1,028 lines

******************************* DATA ************************************* ASM32 data manipulation subroutines Copyright (C) 1993 Douglas Herr all rights reserved ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ CHRDEL: deletes a character from a string The resulting space is closed by moving the remaining characters forward Source: chrdel.asm (strlen.asm) Call with: EBX pointing to an ASCIIZ string EAX = offset from EBX to character to delete Returns: ECX = new string length Uses: ECX Example: lea ebx,string ; EBX points to string mov eax,3 ; delete character at [EBX+3] call chrdel ; delete the character, shorten string ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ COLORATTR: calculate a color attribute for ASM32's text-mode subroutines. Intended for 16-color text modes. Source: coloratt.asm Call with: AL = foreground color (0 - 15) AH = background color (0 - 15) Returns: AH = color attribute Uses: AX Example: include codeseg.inc . . . mov al,hired ; bright red mov ah,blue ; blue call colorattr ; this should get their attention mov warning,ah ; save the attribute ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ CSET: centers a string in a fixed field Source: cset.asm (strlen.asm) Call with: EDI pointing to address of field string ESI pointing address of string to be centered in the field Both strings must be zero-terminated (ASCIIZ). The field string may not contain any nul characters except for the terminator. Returns: CF = 0 if no error CF = 1 if string was truncated to fit in the field Uses: CF; all other flags and registers are saved Example: lea edi,field ; field string lea esi,source ; string to be centered in field call cset ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ DAYNAME: returns a pointer to an ASCII string for specified day of the week Source: dname.asm ($mname.asm) Call with: AX = day of week (1 - 7, Monday = 1) Returns: [EBX] = pointer to day name string ECX = length of new string Note that the day name string is not zero-terminated strndup may be used to copy the string to the near heap Uses: EBX, ECX Example: mov ax,day call dayname ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ FILL4, FILL4b: fill a buffer with specified 4-byte data Source: fill4.asm Call with: ESI pointing to 4-byte data (integer, float or other) EDI pointing to buffer ECX = number of 4-byte data blocks to fill in buffer Fill4b: EBX = byte increment between data blocks Returns: nothing Uses: nothing Example: include codeseg.inc extrn fill4:near ; data wonowon dd 101. ; float4 value buffer dd ? ; program allocates buffer, stores address here ; code . . . lea edi,buffer lea esi,wonowon ; fill every other 4-byte block in far segment mov ebx,8 ; skip 4 bytes between data blocks mov cx,25 ; do it 25 times cal fill4 ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ FILL8, FILL8b: fill a buffer with specified 8-byte data Source: fill8.asm Call with: ESI pointing to 8-byte data (integer, float or other) EDI pointing to buffer ECX = number of 8-byte data blocks to fill in buffer Fill8b: EBX = byte increment between data blocks Returns: nothing Uses: nothing Example: see Fill4 ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ FSTRISTR: search for a string in a disk file, case insensetive Source: fstristr.asm (strlen.asm, $strstr.asm, strnupr.asm) FSTRSTR: search for a string in a disk file, case sensetive Source: fstrstr.asm (strlen.asm, $strstr.asm) Call with: BX = file handle, ESI points to string to find The file must have been opened with read access. Returns: if CF = 0, EAX is the offset of the string in the file if CF = 1: string not found if EAX = -1 error reading file if EAX = -2 Uses: EAX, flags Example: include codeseg.inc extrn fstrstr:near ; data string db 'A String In The File',0 filename db 'anyold.fil',0 ; code yoursub proc near mov edx,offset filename mov al,0 ; open the file with read access call $fopen jc short no_good mov bx,ax mov esi,offset string ; ESI points to the string call fstrstr jc short no_good ; returns with EAX = string offset ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ GETCMD: isolates command line parameters GetCMD assumes that parameters are separated by one or more spaces Source: getcmd.asm Call with: AL = parameter number (first command line parameter = 0) Returns: EBX = near pointer to copy of command line parameter ECX = length of parameter string ECX = 0 if no command parameter(AL) Uses: EBX, ECX, flags Example: include codeseg.inc extrn getcmd:near ; code . . . mov al,0 ; get first parameter call getcmd ; returns with EBX pointing to parameter ; and ECX = length of parameter jecxz no_parameters ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ I2TOSTR: convert an integer value to an ASCIIZ string Source: i2tostr.asm (i4tostr.asm) I4TOSTR: convert a long integer value to an ASCIIZ string Source: i4tostr.asm ASM32's TPrint, GPrint and other 'print' subroutines require a string argument. Numeric data must be converted to a string before printing. Call with: [ESI] pointing to a buffer space; must be 12 bytes or bigger (i2tostr) AX = integer value (i4tostr) EAX = long integer value Returns: ASCIIZ string at [ESI]; numerals are right-justified Uses: nothing; all registers and flags are saved Supports: (i2tostr) signed 2-byte integers (i4tostr) signed 4-byte integers Example: include codeseg.inc extrn i2tostr:near ; data nbuffer db 12 dup(?) ; code . . . lea esi,nbuffer mov ax,32750 ; integer value call i2tostr ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ LSET: left-justifies a string in a fixed field Source: lset.asm (strlen.asm) Call with: EDI = address of field string ESI = address of string to be justified in the field Both strings must be zero-terminated (ASCIIZ). The field string may not contain any NUL characters except for the terminator. Returns: CF = 0 if no error CF = 1 if string was truncated to fit in the field Uses: CF all other flags and registers saved Example: lea edi,field ; field string lea esi,source ; string to be justified in field call lset ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ LTRIM: remove leading blanks from an ASCIIZ string Source: ltrim.asm (strlen.asm) Call with: EBX pointing to string Returns: ECX = new string length Uses: ECX Example: lea ebx,string call ltrim ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ MAXI2, MAXI2b: find maximum value in a signed integer array Source: maxi2.asm MINI2, MINI2b: find minimum value in a signed integer array Source: mini2.asm MAXU2, MINU2b: find maximum value in an unsigned integer array Source: maxu2.asm MINU2, MINU2b: find minimum value in an unsigned integer array Source: minu2.asm Call with: EDI pointing to the array ECX = number of array elements For max/min?2b, call with EBX = byte increment between array elements. Max/min?2 assume increment = 2. Returns: EAX = array element number with maximum value see example to calculate address of maximum value if subroutine was called with ECX = 0, CF = 1 Uses: EAX, CF Example: include codeseg.inc extrn maxi2:near ; data integers dw 140 dup(0) ; code . ; program establishes array values . . lea edi,integers mov ecx,140 ; search the entire array call maxi2 shl eax,1 ; convert word offset to byte offsest add edi,eax ; EDI points to the maximum value ; With max/min?2b, the offset of the ; value is EDI + (EAX * EBX). ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ MAXI4, MAXI4b: find maximum value in a signed 4-byte integer array Source: maxi4.asm MINI4, MINI4b: find minimum value in a signed 4-byte integer array Source: mini4.asm MAXU4, MAXU4b: find maximum value in an unsigned 4-byte integer array Source: maxu4.asm MINU4, MINU4b: find minimum value in an unsigned 4-byte integer array Source: minu4.asm Call with: EDI pointing to the array ECX = number of array elements For max/min?4b, call with EBX = byte increment between array elements. Max/min?4 assume increment = 4. Returns: EAX = array element number with maximum value see example to calculate address of maximum value. if subroutine was called with ECX = 0, CF = 1 Uses: EAX, CF Example: include codeseg.inc extrn maxi4:near ; data int4 dd 140 dup(0) ; code . ; program establishes array values . . lea edi,int4 mov ecx,140 ; search the entire array call maxi4 shl eax,2 ; convert dword offset to byte offset add edi,eax ; EDI points to the maximum value ; With max/min?4b, the offset of the ; value is EDI + (EAX * EBX). ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ MEMCOPY: copy data, checking for overlap if ES = DS Source: memcopy.asm Call with: DS:[ESI] = source address ES:[EDI] = destination address ECX = bytes to move Returns: nothing Uses: nothing Example: extrn memcopy:near include dataseg.inc farmem dw ? ; selector of far memory block source dd ? ; offset in far memory block destination dd ? ; destination offset @curseg ends include codeseg.inc . . . push ds push es mov esi,source mov edi,destination mov ax,farmem mov ds,ax mov es,ax call memcopy pop es pop ds ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ MONTHNAME: returns a pointer to an ASCII string for specified month Source: mname.asm ($mname.asm) Call with: AX = month (1 - 12, January = 1) Returns: [EBX] = pointer to month name string ECX = length of month string Note that the month name string is not zero-terminated strndup may be used to copy the string to the near heap Uses: EBX, ECX Example: mov ax,month call monthname ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ PATH: finds path strings in program enviornment isolates each path in "PATH=" part of enviornment Source: path.asm (strlen.asm, heap.asm) Call with: EAX = path number Returns: EBX points to a copy of path(EAX), ECX = length of path. The copy of the path string is located in the low memory area; when you are done using it, release the memory used by the string with HFREE. If ECX = 0, path(EAX) does not exist. The first path in the enviornment is path(0). Uses: EBX, ECX, flags Example: include codeseg.inc extrn path:proc ; code . . . xor eax,eax ; start with the first path find_path: call path jecxz no_path ; exit if no more paths, or else EBX points ; to a copy of the first path in the enviorment ; strndup). inc eax ; look for next path jmp find_path no_path: . . ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ RANDOM: generates a near-random number Source: random.asm Call with: no parameters Returns: AX = near-random number between 0 and 65535 you may notice repeating patterns every few thousand calls to Random. Uses: AX Example: call random ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ RSET: right-justifies a string in a fixed field Source: rset.asm (strlen.asm) Call with: EDI = address of field string ESI = address of string to be justified in the field Both strings must be zero-terminated (ASCIIZ). The field string may not contain any nul characters except for the terminator. Returns: CF = 0 if no error CF = 1 if string was truncated to fit in the field Uses: CF; all other flags and registers saved Example: lea edi,field ; field string lea esi,source ; string to be justified in field call rset ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ RTRIM: removes trailing blanks from an ASCIIZ string Source: rtrim.asm (strlen.asm) Call with: EBX pointing to string Returns: ECX = new string length Uses: ECX Example: lea ebx,string call rtrim ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ SORTI4HI: sort an array of 4-byte signed integers, highest first Source: sorti4hi.asm SORTI4LO: sort an array of 4-byte signed integers, lowest first Source: sorti4lo.asm Call with: EDI = address of first element of array to sort ECX = number of array elements; assumes ECX < 1 Gigabyte Returns: nothing Uses: nothing; all registers and flags are saved Example: extrn sorti4hi:near include dataseg.inc i4data dd 1500 dup(0) @curseg ends include codeseg.inc . ; program establishes data values . . lea edi,i4data mov ecx,1500 call sorti4hi ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ STRTOI4: converts an ASCII string to an integer value STRNTOI4: converts n bytes of an ASCII string to an integer value Source: strtoi4.asm Call with: ESI = address of string strntoi4 only: ECX = number of bytes to read Returns: EAX = integer value strtoi4: ESI points to character past terminating byte strntoi4: if ECX = 0, ESI points to next character if ECX <> 0, ESI points to character past terminating byte BL = error code bit 0 if set = CR read before reading any numeric characters bit 1 if set = CR was the terminating character bit 6 if set = overflow; result in EAX is unusable bit 7 if set = result is unsigned; result is unusable if the value represented by the string was negative Uses: EAX, EBX, ECX, ESI, flags Example: include codeseg.inc ; data number_string db '1234567',0 ; code . . . lea esi,number_string ; point to '1234567' mov ecx,7 ; 7-byte field call strntoi4 ; return result as an integer in EAX ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ STRCAT: catenates (combines) two ASCIIZ strings Source: strcat.asm (strdup.asm, strlen.asm, heap.asm) Call with: ESI = address of first string EBX = address of second string Returns: if CF = 0, EBX = address of combined ASCIIZ string if CF = 1, insufficient memory available in low heap Uses: EBX, ECX, CF Example: include codeseg.inc extrn strcat:near ; data string0 db 'this string goes first',0 string1 db ' this one is added at the end of the first',0 ; code . . . lea esi,string0 ; address of first string lea ebx,string1 ; address of second string call strcat ; result returned at EBX jc heap_is_full ; original strings are undisturbed ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ STRCHR: search an ASCIIZ string for a specified character STRNCHR: search n bytes of an ASCII string for a specified character Source: strchr.asm (strlen.asm) Call with: EBX = pointer to ASCIIZ string AL = character to find ECX = number of bytes to search (strnchr only) Returns: ECX = string length if CF = 0, EAX is the offset from EBX to matching character in the source string if CF = 1, no matching character found Uses: ECX, EAX, CF Example on next page ; use STRNCHR to determine if a key pressed was a legal key include codeseg.inc extrn strnchr:proc, getkey:proc, toupper:proc ; data valid_string db 'ABC123',27 ; keys 1,2,3,A,B,C and Esc valid_len equ $-valid_string ; number of valid keys dispatch_table label word dd akey, bkey, ckey, onekey, twokey, threekey, esckey ; code . . . get_another: lea ebx,valid_string ; EBX points to a string of valid keys call getkey ; keycode returned in EAX shr ah,1 ; test for extended keycode jc get_another ; I'm not interested in extended keycodes today call toupper ; convert keycode to upper case mov ecx,valid_len call strnchr jc get_another ; CF = 1 if key pressed is not among the ; keys in the validation string mov ebx,eax shl ebx,1 ; convert byte offset to word offset jmp dispatch_table[ebx] akey: . . . bkey: . . . ckey: . . . ; etc ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ STRCPY: copy an ASCIIZ string to existing buffer Source: strcpy.asm (strlen.asm, strncpy.asm) Call with: ES:[BX] pointing to ASCIIZ string DS:[SI] pointing to destination buffer STRCPY assumes that the buffer is long enough to hold the entire string. The string's terminating NUL byte is not copied to the buffer. Returns: CX = string length Uses: CX Example: include asm.inc extrn strcpy:proc .fardata fstring db 'a far string',0 .data string_buffer db 128 dup (?) .code . . . ; copy far string to DGROUP for convenient manipulation mov ax,@fardata mov es,ax assume es:@fardata mov bx,offset @fardata:fstring call strcpy ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ STRNCPY: copy CX bytes to an existing buffer Source: strncpy.asm Call with: ES:[BX] pointing to ASCII string DS:[SI] pointing to destination buffer CX = number of bytes to copy STRNCPY assumes that the buffer is long enough to hold the entire string Returns: nothing Uses: nothing; all registers and flags are saved Example: ; I want to copy a command line parameter to DGROUP include asm.inc extrn getcmd:proc extrn strncpy:proc .data extrn pspseg:word ; PSP segment address was saved by STARTUP string_buffer db 128 dup (?) .code . . . mov es,pspseg xor ax,ax ; first command line parameter call getcmd ; returns parameter at ES:[BX], length as CX jcxz no_parameters lea si,string_buffer call strncpy ; make it zero-terminated add si,cx mov byte ptr [si],0 ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ STRINS: inserts string1 in string0 at specified offset. Creates new string in low heap; first part of new string is n bytes of string0; middle of new string is string1; end of new string is remainder of string0. Source: strins.asm (strlen.asm, heap.asm) Call with: ESI pointing to string0 EBX pointing to string1 EAX = offset in string0 to insert string1 Returns: if CF = 1, insufficient memory in hear heap if CF = 0, EBX points to new string Uses: EBX, CF Example: include codeseg.inc extrn strins:near ; data string0 db '1234567890',0 string1 db 'abcdefghij',0 ; code . . . lea esi,string0 ; address of first string lea ebx,string1 ; address of second string mov eax,3 ; string1 inserted after '123' call strins ; result returned at EBX jc heap_is_full ; original strings are undisturbed ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ STRDUP: duplicates an ASCIIZ string Source: strdup.asm (strlen.asm) STRNDUP: duplicates n bytes of a string Source: strdup.asm Call with: EBX = address of source string (strndup) ECX = number of bytes to duplicate strdup requires an ASCIIZ string; strndup duplicates ECX characters at [EBX] whether zero-terminated or not. The duplicate created by strdup or strndup will be an ASCIIZ string. Returns: if CF = 0, EBX = address of string copy in low memory ECX = string length if CF = 1, insufficient memory in low memory Uses: EBX, ECX, flags Example: lea ebx,source ; EBX = source address call strdup jc oops ; not enough memory if CF = 1 ; otherwise, EBX = address ; of string copy ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ STRIPCHR: remove all occurances of a character from an ASCIIZ string. Source: stripchr.asm (strlen.asm) Call with: EBX = string address AL = character to remove from the string Returns: ECX = new string length Uses: ECX Example: lea ebx,string ; EBX -> string mov al,'$' ; remove "$" character from string call stripchr ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ STRLEN: finds length of an ASCIIZ string Source: strlen.asm Call with: EBX = address of the string Returns: ECX = length of string excluding the terminating NUL Uses: ECX Example: lea ebx,string call strlen ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ STRLWR: changes upper-case characters in a string to lower case Source: strlwr.asm STRNLWR: changes a string of known length to lower case Source: strnlwr.asm Call with: EBX = address of an ASCIIZ string ECX = number of bytes (strnlwr only) Returns: nothing Uses: nothing Example: lea ebx,string call strlwr ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ STRRCHR: find the last byte in a string matching AL STRNRCHR: find the last byte in n bytes matching AL Source: strrchr.asm (strlen.asm) Call with: EBX pointing to the first character of the string AL = byte to find (strnrchr only) ECX = number of bytes to search Returns: if CF = 1, no match if CF = 0, EAX = offset from EBX of the last matching byte Uses: EAX, CF; all other flags and registers are saved Example: include model.inc extrn strrchr:near dataseg.inc string db 'my old computer was a real slug',0 @curseg ends include codeseg.inc . . . mov al,'w' ; look for the lower-case "w" lea ebx,string call strrchr jc oops ; cut outta here if not in the string ; else go on ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ STRREV: reverses all characters in a string STRNREV: reverses n characters in a string Source: strrev.asm (strlen.asm) Call with: EBX pointing to the first character of the string ECX = number of bytes in string to reverse (strnrev only) Returns: ECX = string length Uses: ECX; all other registers and flags saved Example: lea ebx,string ; EBX points to ASCIIZ string call strrev ; also returns ECX = string length ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ STRSPACE: creates an ASCIIZ string filled with the space character, terminated with NUL Source: strspace.asm (heap.asm) Call with: EAX = string length (not including terminating NUL) Returns: if CF = 1, insufficient memory in near heap if CF = 0, EBX points to the new string ECX = string length (should be same as EAX) Uses: ECX, EBX, CF Example: mov eax,14 ; make a new string 14 characters long call strspace jc short oops ; not enough memory if CF = 1 mov string14,ebx ; else save pointer to string ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ STRSET: sets all bytes of an ASCIIZ string to a specified character STRNSET: sets n bytes of an ASCIIZ string to a specified character Source: strset.asm (strlen.asm) Call with: EBX pointing to a valid ASCIIZ string AL = character ECX = number of bytes to set (strnset only) Returns: ECX = string length Uses: ECX Example: lea ebx,string ; EBX points to an ASCIIZ string mov al,'*' call strset ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ STRSTR: finds the first match with a target string in a source string case sensetive Source: strstr.asm ($strstr.asm, strlen.asm) STRISTR: finds the first match with a target string in a source string case insensetive Source: stristr.asm (strstr.asm, strdup.asm, strupr.asm, heap.asm) STRRSTR: finds the last match with a target string in a source string case sensetive Source: strrstr.asm (strrev.asm, $strstr.asm) Call with: EDI pointing to source string, ESI pointing to target string. Returns: if CF = 0, EAX = offset of target in source string. if CF = 1, no match Uses: EAX, CF; all other flags and registers are saved Example: include model.inc include dataseg.inc string db 'Monday',0 substring db 'day',0 @curseg ends include codeseg.inc . . . lea edi,string ; source = 'monday',0 lea esi,substring ; target = 'day',0 ; find the offset of 'day' in 'Monday' call strstr ; in this example, strstr returns EAX = 3 ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ STRUPR: changes lower-case characters in an ASCIIZ string to upper case Source: strupr.asm STRNUPR: changes lower-case characters in an n-length string to upper case Source: strnupr.asm Call with: EBX pointing to string (strnupr only) ECX = number of bytes in string Returns: nothing Uses: nothing Example: mov ebx,offset string mov ecx,bytes call strnupr ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ SWAPB: swaps ECX bytes at DS:[ESI] with the bytes at ES:[EDI] Source: swapb.asm Call with: ESI pointing to one of the data areas, EDI pointing to the other ECX = number of bytes to swap Returns: nothing Uses: nothing; all registers and flags are saved Example: include model.inc extrn swapb:near include dataseg.inc string1 db 'this is string 1',0 string2 db 'this is string 2',0 strings dw string1, string2 ; addresses of the strings ; this trivial example will swap ; the string pointers @curseg ends include codeseg.inc public stringswap stringswap proc near . . . lea esi,strings mov edi,esi mov eax,2 ; each string pointer is 2 bytes add edi,eax ; point to 2nd pointer call swapb