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Text File | 1990-11-28 | 119KB | 2,921 lines

----FAR--DARTER----> s o f t w a r e Presents _____________ ____ ____ | | ____ ____ | _________| ____ ____ | | ____ ____ | |_______ ________ | | ______ | _______| ____ | | ______ | | ________ | | ____ ____ | | ____ ____ | | ____ ____ |___| ____ ____ F i l e e X a m i n e r ****************************** * * * User Documentation * * * * Version 1.1 * * * ****************************** Copyright 1990 William Noble All Rights Reserved LIMIT OF LIABILITY FX is distributed as-is. The author disclaims all warranties, expressed or implied. The author will assume no liability for damages either from the direct use of this product or as a consequence of the use of this product, nor be liable for any damage to data or property which may be caused either directly or indirectly, intentionally or unintentionally, from the use of this product. ______________________________________________________ FX was designed for the legal and legitimate examination and repair of personal files. It was NOT designed to alter programs or files that are copyrighted or owned by other individuals or companies! Doing so may very well be illegal, and will at the least probably void any warranty or other legal rights extended to the purchaser of the programs or files thus affected. The author can not, and will not, assume any responsibility or liability for those who use this program irresponsibly! ______________________________________________________ Shareware FX is distributed as shareware, which affords users the opportunity to evaluate programs BEFORE they are purchased. If the program is then judged effective and practical for individual needs and is used regularly, one registers the program with the author. If you use FX on a regular basis and find it a functional, worthwhile program, we sincerely hope you will register in keeping with the philosophy and practice of user-supported software. The basic single-user registration fee we request is $15. (Please see the end of the documentation for full registration details). FX, like most shareware, required a substantial amount of time and skill to design and program, and is, we feel, on a par with commercially available packages in all respects. Regardless of whether you register your copy of FX, we encourage you to copy it and pass it along to friends and acquaintances for their own evaluation and trial use! (Needless to say, all copies made are understood to be for the non-commercial, private trial use of others). Consistent with the custom of user-supported software, you may receive a copy of FX by sending us a blank, formatted disk together with an addressed, POSTAGE PAID return mailer. The FX program and documentation on disk will be mailed back on your diskette. Trademark Acknowledgments dBASE is a registered trademark of Ashton- Tate Corporation. Epson MX is a trademark of Epson America, Inc. IBM and IBM PC are registered trademarks of International Business Machines Corporation. Microsoft, Microsoft C, Microsoft C Compiler and MS-DOS are registered trademarks of Microsoft Corporation. Turbo Assembler (TASM) is a registered trademark of Borland International, Inc. Contents Introduction 1 FX Quick Start 2 Hardware Requirements 3 Mouse Support 3 Installation 4 Invoking FX 4 Using Menus and Input Areas 8 Using the Numeric Entry Box 8 Basic Concepts 10 Using FX- Overview 11 Moving through the File 11 Selecting Display Modes 12 Synopsis of FX Commands 13 The Major FX Functions 15 Selecting a File To Examine 15 Locating Byte Patterns 16 Counting Byte Patterns 18 Modifying a File Byte 18 Jumping Directly to Any Byte 18 DOS Shell 19 Major Display Formatting Options 20 Changing the Display Mode 20 Selecting the Numeric Display 22 Toggling Hexadecimal Status Line Notation24 Optimizing the Display for ".DBF" Files 24 Understanding The FX Display 26 StartByte 27 Recsize 27 Tab Amount 28 File Byte 28 Record 28 Recbyte 29 Modified 29 Using FX with dBASE database files 30 Examining the field definitions 31 Examining the data 32 Summary of FX Messages 33 Error Handling 36 FX Command Summary 37 Notes 38 FX Registration Information A FX User Documentation Version 1.1 _________________________________________________________________ Introduction FX (File eXaminer) is a general-purpose file viewer and "byte- zap" utility. It can handle any file possible under MS-DOS, and of unlimited size; it is neither constrained by nor optimized for any particular file format, whether that be ASCII text, binary, etc. This program was designed to be as fast, flexible and reliable as possible, working as a sort of "byte-oriented" word processor. Note that FX enables viewing and modification of the ENTIRE contents of a file, INCLUDING any end-of-file marks (Control-Z, ASCII value 26 decimal). Please note that FX will not insert bytes or remove bytes-- only modify existing ones. In addition, FX does not create any "temporary" or "intermediate" files-- one is working DIRECTLY against the selected file! If it is planned to modify bytes, (especially in an executable file), and there is the least doubt about the impact of the changes, WORK WITH A COPY OF THE FILE, AND NOT THE ORIGINAL! Be assured that FX is completely safe to use on ANY file-- it will not modify any aspect of a file unless specifically requested to do so, and doing so requires an overt, conscious decision by the user. Unintentional changes are almost impossible. If there is the least doubt, however, it is again strongly recommended the file be backed up first. Any of the following tasks may be easily accomplished with FX: - Scroll through and examine ANY portion of ANY file as if it were a word processing document, displaying the data in any mix of ASCII, decimal or hexadecimal notation. - Locate or Count byte patterns. - Format the display to expose the underlying file structure. - Modify any byte in any file, regardless of its location. - Read PAST any end-of-file marks, (Control-Z, decimal ASCII 26), right to the end of the file's physical extent as recorded by DOS. - Continuously watch the value of the byte, integer and long integer at any file position in terms of decimal, hexadecimal or binary notation. _________________________________________________________________ (C) 1990, William Noble Page 1 FX User Documentation Version 1.1 _________________________________________________________________ Typical uses of FX include: - Repairing damaged files. - Removing intermediate end-of-file marks in text files that prevent access to the full contents of the file. - Scanning executable code for messages indicative of a program with "ulterior motives", e.g. "Viruses" and the like. - Customizing executable programs. Many ".COM" programs are accompanied by a discussion of which bytes to modify to customize their display colors and other configuration options. (Typically, this is done using the "DEBUG" program, but FX is far easier to use and better suited to such a task). - Programmers can use FX to inspect and debug files created by their own programs. - Deciphering foreign file formats. FX Quick Start FX is started simply by issuing the command "FX". FX can also accept a number of wholly optional command-line parameters. Please refer to the section "Invoking FX" for full details. Once FX is running, ALT-H will pop up the help screen at any point in the program. Also, hitting the forward slash key ("/") will invoke the FX command menu, which may be used to familiarize oneself with, and optionally invoke, FX commands. _________________________________________________________________ (C) 1990, William Noble Page 2 FX User Documentation Version 1.1 _________________________________________________________________ Hardware Requirements FX will run on any IBM PC or true compatible running DOS 3.0 or higher, and should certainly run without incident on a 256K system. (FX will require about 200K available memory to run). FX automatically detects and adapts to a monochrome or color system, and selects 25 by 80 text mode if the system is not already in this mode. (FX restores the video mode and cursor size upon exit). Since the program writes directly to video memory for the best possible performance, it also accounts for CGA monitors and takes the proper measures to avoid the "snow" effect. Note to Network Users: This program was designed to function in network, as well as single-user, environments. FX opens all files in accord with the SHARE program. This has no impact whatsoever on single-user systems, or on systems not running SHARE. However, if SHARE is installed, then note that FX will open all files as "Deny Write"; that is, other programs can read from a file in use by FX, but NOT write to it. A file is opened by FX when it is selected with the FILE command, and closed only when another file is chosen or the program is exited. Mouse Support FX will automatically detect and support a Microsoft-compatible mouse, if installed. FX neither uses nor displays a "mouse cursor", but instead translates the relative movement of the mouse into an equivalent press of the up, down, left and right arrow keys. Moving the mouse up, for instance, is the same as repeatedly pressing the up-arrow key. Clicking BOTH buttons simultaneously and releasing them is always equivalent to pressing ESCAPE. _________________________________________________________________ (C) 1990, William Noble Page 3 FX User Documentation Version 1.1 _________________________________________________________________ At menus, clicking either button by itself and releasing it is the same as pressing ENTER on the keyboard. When in the file window, the buttons are put to some use: - Clicking and releasing the LEFT button is equivalent to PgUp (Previous screenful) - Clicking and releasing the RIGHT button is equivalent to PgDn (Next screenful) The primary reason for supporting the mouse is not for making menu selections, (although it can be used for that), but instead for moving the cursor about in the File Window. Installation FX does not require a formal installation as such- the only file required to run FX is, simply enough, "FX.exe". To "install" FX is to COPY the file "FX.exe" to any desired location. On hard disk systems, it would certainly be recommended that this be a directory that is on the "search path", (any directory that is named in the PATH environment variable), so the system can find FX regardless of the current working directory. Invoking FX New in version 1.1 is full support for command line parameters; nearly every aspect of FX can now be configured in this way. A listing of these options is available at any time by simply invoking FX with the "/?" option: FX /? FX will list the options to the standard output (usually the screen unless redirection (>) is used), and stop. The "full dress" form of FX version 1.1 is therefore: FX filename /A /H /J /M /N /Q /R /S /T /? These options may be typed in any order, in upper or lower case, and must be separated by spaces. Each one is optional, and they can be mixed and matched to suit the need at hand, or specified in batch files to invoke FX with special often-used configurations. _________________________________________________________________ (C) 1990, William Noble Page 4 FX User Documentation Version 1.1 _________________________________________________________________ <filename> The name of the file that FX will automatically load upon starting. This may be any legal DOS filename, and should include a drive and/or path if the file is not in the current working directory. If no filename is present on the command line, or FX cannot locate the file specified, then the file selection box will automatically pop up as usual. /A Start in Pure Alphanumeric display mode. /Annn Specify numeric ASCII value <nnn> of the character to use when in Alpha-Numeric display mode. By default, FX uses a small dot, ASCII 250. Any character may be used from the IBM character set, from 0-254. For example, "/A95" or "/A240". /H Cause FX to start with hexadecimal status line notation enabled. /Jnnn *** Jump automatically to byte <nnn>. (A file must be supplied on the command line for this option to have any effect). The value must be in the range 0 - (file size -1). Note that if the "/S" switch is used to set the starting display byte ("StartByte"), then this value becomes the lower bound for the Jump value. If the value is out of range, FX will position the cursor at byte 0. /Mn Default starting file display mode, where <n> is a number 1-7. /Nchar Starting numeric display mode. One of four characters (upper or lower case) must immediately follow the "/N": (N)one (B)inary (D)ecimal or (H)exadecimal. /Q Skip the signon screen (Quiet). By default, FX will display an initial title screen containing a copyright notice and shareware information. This screen can be skipped by adding a "/Q" to the command line. _________________________________________________________________ (C) 1990, William Noble Page 5 FX User Documentation Version 1.1 _________________________________________________________________ /Rnnn Set default starting record size to <nnn> bytes. This value must be in the range 1-3610 decimal in this version of FX. /Snnn *** Set starting byte to <nnn>. This switch sets the "StartByte" value, but like the "/J" switch, a file must be supplied on the command line for this option to have any effect. It must be in the range 0 - (file size in bytes - 1). /Tnnn Set the tab amount, 1-65000 decimal. /? Display list of command line options The starred (***) items /J and /S are ONLY meaningful when a filename is present. Notes: - Either a foreword slash (/) or minus sign (-) may be used as the switch character. - Numeric arguments must immediately follow the 2- character switch, and are assumed to be in decimal (base 10) notation. If it is preferred to enter any value in hexadecimal notation, an "H" must be appended to the number, forcing FX to evaluate it as a hexadecimal quantity. For example, "/TffH" or "/JFEh". _________________________________________________________________ (C) 1990, William Noble Page 6 FX User Documentation Version 1.1 _________________________________________________________________ Some examples of invoking FX with command line options are: FX /q Run FX, skip initial screen. FX A:x.dat /q /NB Run FX, skip initial screen, and examine the file "A:x.dat". Binary numeric display mode is requested as well (/NB). FX c:myfile /T25 /A /A0 /M7 /S150 /J300 /TffH This command tells FX to start automatically with the file "C:MYFILE" in the display window, specifies that alphanumeric display mode be toggled on (/A), sets the alphanumeric display character to ASCII 0 (/A0), starts FX in file display mode number 7 (/M7), sets the starting file byte (StartByte) to 150 (/S150), places the cursor initially at byte 300 (/J300), and sets the tab amount to FF hexadecimal (/TffH). _________________________________________________________________ (C) 1990, William Noble Page 7 FX User Documentation Version 1.1 _________________________________________________________________ Using Menus and Input Areas To use any menu in FX, either press the first letter of the menu item, or highlight the desired item using the Arrow keys, Spacebar or Backspace keys and press ENTER. When entering values in input areas, the following editing keys may be used: - LEFT/RIGHT ARROW KEYS may be used to position the cursor anywhere in an input area. - HOME/END will move the cursor to the first or last position in the area, respectively. - INSERT: Toggles between insert mode and overtype mode. FX starts in overtype mode, meaning typed characters will replace existing ones. In INSERT mode, a block cursor is displayed, and typed characters are inserted, shifting existing characters to the right. - DELETE: Deletes the character at the cursor position, and shifts all characters to the right of the cursor left one position. - BACKSPACE: Deletes the character to the left of the cursor, shifting the remainder of the area left one position. - ESCAPE: Cancel current entry and back up. Using the Numeric Entry Box A special entry box appears when one of the 4 options Startbyte ("S"), Recsize ("R"), Tab Amount ("T") or Jump ("J") is invoked. These are the only FX commands that require a numeric value to be entered by the user. Two entry areas are provided: one for decimal notation, the other for hexadecimal notation. The desired value can be entered in EITHER box, depending on one's inclination. One can switch between the 2 formats by pressing TAB, Shift-TAB or using the Up/Down arrow keys. To the right of each input area is shown the range of valid values between parenthesis. Type in the new value (in decimal or hexadecimal notation depending on the selected entry area) and press ENTER to confirm the new value, or ESCAPE to leave the initial default value unchanged. _________________________________________________________________ (C) 1990, William Noble Page 8 FX User Documentation Version 1.1 _________________________________________________________________ Since it is often necessary to do some math to calculate these values, (and often in hexadecimal, no less!), a simple calculator capability has been provided. If the number entered is PRECEDED by a plus ("+"), minus ("-"), multiply ("*") or divide ("/") character, then that operation is performed as if one were using a 4-function calculator. That is, FX will use the value that was LAST in the box, and perform the calculation requested by the symbol "+", "-", "*" or "/", in the same way that a calculator would: New value = <Last Value> (+-*/) <Value just entered> For example, assume one wishes to modify the default record size by pressing "R". The entry box will pop up, and the default values will look something like this: [ 72] (Dec 1-3610) [ 48] (Hex 1-E1A) If one wanted to increase the default of 72 by 9, one would just type a plus sign ("+") followed by the number we want to add to 72, 9 in this case: [+9 ] (Dec 1-3610) [ 48] (Hex 1-E1A) Then press ENTER. Since FX sees the plus sign, it will calculate this addition and place the answer back into the decimal and hexadecimal areas. The display will now look like this: [ 81] (Dec 1-3610) [ 51] (Hex 1-E1A) Any amount of calculating may be done in this fashion. Pressing ENTER will accept the number displayed as the new value. In summary: [TAB] or Up/Down Arrow Toggle between decimal and hexadecimal entry format. ENTER Accept value currently displayed. If one of the 4 operators (+-*/) precedes the number, then the calculation is performed and the answer placed back into the input areas in both decimal and hexadecimal notation. Press ENTER again to accept this value, or edit it further. ESCAPE Leave the initial default value unchanged and return to the file window. _________________________________________________________________ (C) 1990, William Noble Page 9 FX User Documentation Version 1.1 _________________________________________________________________ Basic Concepts A file is nothing more than a stream of continuous bytes. FX displays these bytes exactly as they occur in the source file, in the same order they occur. The power of FX, however, lies in its ability to format and display this information in a meaningful, flexible manner, and do it very fast. Files are displayed in the FX "File Window", which is always visible and consumes most of the screen display. FX formats files by breaking them up into "RECORDS" of fixed length, displaying one record per display line. Therefore, a "Record" in the context of FX is "The number of file bytes formatted per line in the FX File Window". (In certain display modes, each record may take up as many as 3 rows on the screen; therefore, this "line" may actually be composed of 2 or 3 physical rows in the File Window). The record size can be modified by the user to be anything from 1 byte up to about 3,600 bytes. Please keep in mind that the physical file is still a continuous stream of bytes, and that FX is only VIEWING the file as a series of "records" to unencumber its display. FX starts up with a default record size of 72 bytes. This is by no means a magic number-- it happens to be the number of columns in the display window. In some cases, such as fixed record- length database files, it is meaningful to view the file in terms of a very specific record size, in which case FX can be made to display one database record per line. In other cases, such as executable files like "FX.exe", there is no underlying structure to the file, and the idea of a record size isn't relevant. While running FX, the record size may be repeatedly changed; FX will automatically reformat the file display in the File Window. (This is, by the way, a good technique for uncovering underlying patterns in files). FX also has the unique ability to instantly change its display of file bytes: ASCII, DECIMAL or HEXADECIMAL, or any combination of those three, which amounts to 7 possible display formats. This is covered in detail later in the documentation. _________________________________________________________________ (C) 1990, William Noble Page 10 FX User Documentation Version 1.1 _________________________________________________________________ Using FX- Overview FX uses just one main screen, on which is maintained all information about the file being examined, and which is dominated by the "File Window". This window is the "command center" of FX; it is from here that one examines files and invokes all FX commands. Moving through the File The keys used to move around in the file window are: Left Arrow Move left to the previous byte Right Arrow Move right to the next byte Up Arrow Move up to the previous record Down Arrow Move down to the next record Enter Move to first byte of next record Shift+Enter Move to first byte of previous record Alt <- Jump to the first byte in the record Alt -> Jump to the last byte in the record PgUp Previous screenful PgDn Next screenful Home Jump to first byte in the file window (left edge of screen) End Jump to last byte in the file window (right edge of screen) Ctrl-PgUp Jump to the first record in the file Ctrl-PgDn Jump to the last record in the file Ctrl-Home Jump to first file byte (StartByte) Ctrl-End Jump to last byte in the file F9 Pan left by 1/2 window F10 Pan right by 1/2 window Tab Move forward by tab amount Shift+Tab Move backward by tab amount (A beep will sound if an attempt is made to move past the file boundaries). _________________________________________________________________ (C) 1990, William Noble Page 11 FX User Documentation Version 1.1 _________________________________________________________________ Selecting Display Modes The function keys F1 through F8, shift F1 through F8, and the "H" key, are used to modify aspects of the FX display. Function keys F1 through F7 each correspond to one of the 7 file display modes offered by FX. Function key 8 is used to select the so-called "Numeric Display", which gives detailed information on numeric values that exist at the current position in the file. The "H" key is used to toggle on/off hexadecimal notation for the 2 status lines at the bottom of the screen. These options are covered in detail later on. F1 - F7 Select a Display Mode 1 through 7. SHIFT + F1-F7 Same as above, but also automatically adjusts the number of bytes per record for the given mode. F8 Cycles through the 4 Numeric Display options: Decimal, Hexadecimal, Binary and None. H Causes FX to toggle its hexadecimal status line display on and off. (By default, FX displays the file size, position in the file, etc., in decimal). Toggling this option ON will ALSO affect display mode number 1, causing the record offsets displayed to the left of the File Window to ALSO be toggled to hexadecimal notation. _________________________________________________________________ (C) 1990, William Noble Page 12 FX User Documentation Version 1.1 _________________________________________________________________ Synopsis of FX Commands An alphabetic summary of the FX commands follows. To invoke a command, type either the upper- or lower-case letter indicated between quotes, or select the command from the Options menu: "A"lpha Mode Toggle PURE ALPHA MODE. FX starts with this mode OFF. When toggled ON, all non-alphanumeric characters are displayed as a small dot. "C"ount Count occurrences of byte patterns in the file. "D"atabase Optimize the FX display to isolate sections of dBASE database files. "F"ile Select file to examine. A list of all files in the current directory will be "popped up"- just highlight the desired file and press ENTER. "H"ex Toggle on/off hexadecimal display of values on the status lines and the record offsets when in display mode 1. "J"ump Jump directly to any byte in the file. "L"ocate Locate byte or text patterns "N"ext Jump to next occurrence "R"ecSize Specify the record size, in bytes; that is, the number of bytes that FX will place on each display line. "S"tartByte The byte in the file to begin the display with. FX will ignore all bytes before the StartByte, thus establishing a "new" beginning of file. This is purely for ease of VIEWING the file, and has NO effect on the actual file! ALT-S Sets the StartByte at the current file position. "T"abAmount Specify the number of bytes that will be skipped ahead or backward when TAB or SHIFT-TAB are pressed. e"X"it or Quit FX ESCAPE CONTROL+ENTER Modify current byte. Alt-H Call up the Help screen. Alt-D DOS Shell / Invoke the FX Options Menu. Pressing either the ESCAPE key or the letter "X" will quit FX. If a file has been selected, then a prompt will pop up to confirm that the user wishes to continue and exit the program. _________________________________________________________________ (C) 1990, William Noble Page 13 FX User Documentation Version 1.1 _________________________________________________________________ The Options Menu. To assist in understanding and using the various FX commands, the FX Options Menu is provided. This menu is invoked by typing the forward slash (/). This feature has been added as a convenience, enabling not only the selection of an FX option, but also providing basic information on each one. As the highlight bar is moved up and down (via the Arrow Keys, Spacebar or Backspace), a description of each item is continuously displayed to the right. Options are invoked from this menu the same as from the File Window: by pressing the upper- or lower-case letter, or the desired function key. Also, the currently highlighted option can be invoked by just pressing ENTER. To exit this menu and invoke no option, just press ESCAPE, as usual. _________________________________________________________________ (C) 1990, William Noble Page 14 FX User Documentation Version 1.1 _________________________________________________________________ The Major FX Functions Selecting a File To Examine ("F") All FX sessions begin by selecting a file from the FX file selection box, unless a file was supplied on the command line when FX was started. FX begins in the current working directory on the current drive. The file box will contain every file (*.*) in this directory, as well as a parent directory, if applicable, and any subdirectories. This box provides the full means to navigate throughout the entire directory structure, as well as, of course, selecting files to examine. If a file is chosen from another directory, then that directory becomes the new default FX path for subsequent file selections. Moving the Highlight: Press Up/Down arrow to move the highlight one file at a time, or PgUp/PgDn to move by screenfuls. Press HOME to jump to the first file, and END to jump to the last. SPEED Selection: By pressing the first letter of a filename (upper or lower case), FX will jump to the next file in the list that begins with that letter. Also, one can press the open parenthesis "(" to jump to directory entries, which always begin with this character. Sorting the List: The list of files can be sorted by extension (ALT-X), by name (ALT-N) or by size (ALT-S) to make finding a file easier. (This sort order will remain in effect for subsequent file selections). To select a file to examine, simply highlight the desired file and press ENTER. Press ESCAPE to exit without selecting a file. The FX file selection box also allows one to navigate throughout the current drive by moving up and down the directory tree. The Parent Directory and Subdirectories are enclosed in parentheses () to distinguish them from the other files in the list. If you are currently in the root directory, then of course no Parent directory will be listed. To select the PARENT directory: Highlight the file called "(..) Parent" and press ENTER. The parent directory is selected, and a new list of files for that directory will appear. _________________________________________________________________ (C) 1990, William Noble Page 15 FX User Documentation Version 1.1 _________________________________________________________________ To select a SUBDIRECTORY: Highlight and subdirectory and press ENTER. A new list of files for that directory will appear. To select another drive, press F2. FX determines which drives are configured in the system and displays a menu. Select the desired drive. Note: FX does not change the current working directory or drive. When FX is exited, the system will be at the same drive and directory as when FX was started. Locating Byte Patterns ("L") After invoking Locate, an input area pops up on the top of the screen. Please observe that FX can search for ANY byte value possible in MS-DOS files, INCLUDING ASCII 0. For this reason, not only does FX need to know which bytes to search for, but also the NUMBER of bytes that compose the search string. A moveable vertical "bar" exists in the locate window for this purpose that can be shifted right or left, and all bytes TO THE LEFT of the bar form the search string; all bytes to the right of the bar are ignored. The following keys are used here: - CURSOR UP or CURSOR DOWN: Move cursor to desired input line (ASCII/DEC/HEX). - CURSOR RIGHT, ENTER, or TAB: Move right to next byte. - CURSOR LEFT, SHIFT+TAB or SHIFT+ENTER: Move left to previous byte. - CONTROL-RIGHT ARROW: Move the "bar" right. - CONTROL-LEFT ARROW: Move the "bar" left. - CONTROL+ENTER or F10: Begin the search. - ESCAPE: Return to the File window. The data may be entered in any of 3 formats: ASCII, Decimal or Hexadecimal, depending on one's inclination. A line for each format is provided in the locate window. The first line is for ASCII, the second for hexadecimal, and the last for decimal. Independent of the format chosen to enter the data, the values in the other 2 lines are ALWAYS continuously updated by FX to reflect that value in those other 2 formats. In addition, the bytes may be freely defined in any mix of formats. _________________________________________________________________ (C) 1990, William Noble Page 16 FX User Documentation Version 1.1 _________________________________________________________________ For instance, say it is desired to locate the codes in a printer-driver file that cause an EPSON MX printer to change to bold: "ESCAPE E". The "ESCAPE" character could be entered in decimal by first pressing down arrow twice to get to the decimal line and typing 27. Note the values in the 2 lines above automatically reflect this: the first line will contain the ESCAPE graphic, and the hexadecimal line will contain 1B. Next, one could move to the first line (ASCII) and enter the second byte, the capital letter "E". Again note the 2 lower lines reflect this value. (The letter E could also be entered in its decimal ASCII value, 69, or hexadecimal ASCII value, 45H). Next, one tells FX how many bytes to search for. In this example, we are looking for ESCAPE-E, just 2 bytes. So press CONTROL-RIGHT ARROW once to move the bar to the right 1 byte. All bytes to the left of the bar will form the search string, in this case 2. (If it were decided to search for just the ESCAPE character, one would press CONTROL-LEFT ARROW once to move the bar to the left one byte. Now, just the ESCAPE character will be searched for. Note that there is NO NEED to fiddle with any bytes to the right of the bar: FX ignores them completely). IMPORTANT NOTE: FX begins searching the file from the "StartByte" value. This always defaults to 0 when a new file is selected, meaning the display of the file will begin at its physical beginning. If this value has been modified by the user, then any occurrences in the file before this location won't be found. To search the ENTIRE file, just re-set the StartByte to 0 before invoking Locate. To begin the search, hit F10. FX asks whether the search should be case-sensitive; that is, whether or not the alphabetic characters A-Z and a-z should be compared without regard to case. If "Ignore Case" is selected, then FX considers an "A" to be equal to an "a", and so forth. In this example, "Exact Match" would be the appropriate selection, since ESCAPE-e is not a valid EPSON MX code. FX then asks whether to start the search from the beginning of the file, (that is, from the "StartByte" value), or the current file position- select the desired option. As usual, ESCAPE may be pressed at any point to cancel the LOCATE. Also, ESCAPE may be pressed during the LOCATE to cancel and resume FX in the File window. _________________________________________________________________ (C) 1990, William Noble Page 17 FX User Documentation Version 1.1 _________________________________________________________________ Counting Byte Patterns ("C") The Count function is quite similar to LOCATE. The only difference is that Count does not provide the option of counting from the current file position- count ALWAYS begins at the StartByte. IMPORTANT NOTE: FX counts occurrences STARTING FROM THE StartByte VALUE. If StartByte is larger than 0, then FX will not start counting from the physical start of the file, but from the offset into the file specified by StartByte. To receive an accurate count of occurrences in the ENTIRE file, re-set the StartByte to 0 if it has been changed. Modifying a File Byte (Control-ENTER) Any byte in a file may be modified by pressing CONTROL-ENTER when positioned on the desired byte. (Press and hold the CONTROL key and type ENTER). As with the LOCATE command, an input area appears at the top of the screen, allowing the new value for the byte to be entered in any of 3 formats: ASCII, Decimal or Hexadecimal. Just position the cursor to the box for the desired format by pressing UP ARROW, DOWN ARROW or TAB, then enter the value. The values in the other 2 boxes will be updated and display this value in the other two formats. To commit the change, press either F10 or CONTROL-ENTER. To abort, press ESCAPE. To ensure that the change took place as expected, FX writes out the changed byte and flushes the file buffer, then RE- LOADS and re-displays the current window. This takes almost no time, and verifies the modification beyond question. Please keep in mind that this is the ONLY means by which any byte can be changed in the file. No other sequence of keys or actions will modify a file byte other than pressing CONTROL-ENTER and confirming with F10 or CONTROL-ENTER. Jumping Directly to Any Byte ("J") One may jump directly to any byte position in the file by using the JUMP option. Note that if the starting display byte ("StartByte") has been modified, then that value is the lower bound for the jump. (See the section "Using the numeric entry box" near the beginning of the documentation for full details on entering numbers). _________________________________________________________________ (C) 1990, William Noble Page 18 FX User Documentation Version 1.1 _________________________________________________________________ DOS Shell (Alt-D) FX now provides a DOS shell option, enabling users to quickly exit to DOS and run other programs or DOS commands without ending the current FX session or losing the current configuration. Press Alt-D to activate this feature. When ready to return to FX, type "EXIT" from the DOS command line. Notes: - The file "COMMAND.COM" must be available for this function to work. Make sure the COMSPEC environment variable correctly specifies where to find "COMMAND.COM". This is typically established in the AUTOEXEC.bat file, which contains a line like "SET COMSPEC=<full pathname of COMMAND.COM>. - Do NOT modify or delete the file currently being examined! FX leaves this file OPEN during the DOS Shell, and upon re-entry checks for its existence. If it cannot be found, then FX will stop at once and return to DOS. If ANY work is done on this file while in the DOS Shell, then the results may be unpredictable! - This command IS NOT a substitute for quitting FX! After invoking the DOS Shell option, always type "EXIT" to return to FX, then hit "ESCAPE" or "X" to quit FX in the normal fashion. - If an error message is received when trying to invoke the DOS Shell, please refer to the section "Summary of FX Messages" at the end of the documentation. _________________________________________________________________ (C) 1990, William Noble Page 19 FX User Documentation Version 1.1 _________________________________________________________________ Major Display Formatting Options Changing the Display Mode (F1-F7) and "A" One of the most powerful features of FX is its ability to display a file in any of 7 different formats. In addition, any format may be toggled to "Pure Alpha" by pressing the letter "A", making it much easier to look for text in a binary file. In "Pure Alpha" mode, only standard alpha- numeric characters are displayed; all other characters (high-bit graphics with ASCII values above 127 and graphics from ASCII 1-31) are displayed as a small dot. However, since the display does not accurately reflect the bytes in the file, bytes cannot be modified in pure alpha mode. (When this mode is enabled, the text "[PURE ALPHA-NUMERIC DISPLAY MODE]" will appear on the lower-left corner of the File window box). The best way to become acquainted with each display format is to try out all 7 while running FX. These formats account for every combination of ASCII, Hexadecimal, and Decimal notation, and are summarized as follows: Format 1 ASCII, one row displayed per record. Format 2 Hexadecimal, one row displayed per record. Format 3 Decimal, one row displayed per record. Format 4 ASCII on first row, hexadecimal on second row. Format 5 ASCII on first row, decimal on second row. Format 6 Hexadecimal on first row, decimal on second row. Format 7 ASCII on first row, hexadecimal on second row, and decimal on third row. Bear in mind that in modes 4, 5, 6 and 7, the file bytes that are normally displayed on one row in the first three modes will now require TWO or THREE rows on the screen. For example, in mode 6 (Function key 6 was pressed) each record from the file will occupy TWO rows in the File Window: The first will reflect the data in hexadecimal notation, and the second will display the same data in decimal form. The cursor block will be 3 columns wide, and 2 rows high in order to contain the 2 display lines. Although the cursor is larger, it is STILL only reflecting ONE byte in the file! _________________________________________________________________ (C) 1990, William Noble Page 20 FX User Documentation Version 1.1 _________________________________________________________________ The cursor size ("Cell" size) will automatically adjust depending on the display mode, since the cell must be able to hold the largest value that can occur in the current mode. For instance, in DECIMAL mode (mode 3), the "Cell Size" is one row high and 3 columns wide, since three-digit numbers can occur. Remember that no matter which format is selected, the cell is still just reflecting ONE byte in the file. As mentioned before, the display mode is selected by pressing F1 through F7 or SHIFT F1-F7. The characteristics of each mode are summarized as follows: Key Display Mode Cell Size --- --------------------------- ------------------ F1 FORMAT 1- ASCII 1 row x 1 column F2 FORMAT 2- HEX 1 row x 2 columns F3 FORMAT 3- DEC 1 row x 3 columns F4 FORMAT 4- ASCII + HEX 2 rows x 2 columns F5 FORMAT 5- ASCII + DEC 2 rows x 3 columns F6 FORMAT 6- HEX + DEC 2 rows x 3 columns F7 FORMAT 7- ASCII + HEX + DEC 3 rows x 3 columns Note that the display mode may be freely changed as often as desired- FX will always maintain the cursor at the same file byte. If SHIFT is pressed along with any of the above function keys (F1-F7), the display mode is not only selected as above, but FX will also automatically increase or decrease the record size (RecSize) value so that each line fits exactly in the display window. For example, if one pressed F7 to switch to format seven from format one, only one-third as many bytes would be visible at a time- the remainder being off to the right or left of the window. Pressing SHIFT-F7, however, would reduce the record size, (# bytes per line), by one-third as well to 24 bytes per record. Note on multi-row modes (Format 4 - Format 7): On a monochrome monitor, the last row of each record will be underlined. On a color monitor, the last row will be displayed in a contrasting color. _________________________________________________________________ (C) 1990, William Noble Page 21 FX User Documentation Version 1.1 _________________________________________________________________ Selecting the Numeric Display (F8) The value of the Byte, Integer, and Long-Integer at the current file position is continuously displayed at the top center of the screen. Each press of F8 cycles through the 4 display options: 1) DECIMAL notation (default) 2) HEXADECIMAL notation 3) BINARY notation 4) No Display: Center top of screen left blank. A BYTE is one character (byte) in length and is the basic building block of MS-DOS files. Each byte is composed of 8 "bits", each having one of two possible values: 1, meaning that bit is "set", or 0, meaning that bit is "cleared". The bits in a byte are numbered from 0-7. Bit 0 is known as the "least significant" bit position, and has a weight of 1. Bit 7 is the "most significant" position, with a weight of 128. This is analogous to the base 10 numbering system, where the right-most position has a weight of 1, the one to its left a weight of 10, then 100, 1000, and so on. An INTEGER is 2 bytes, and a LONG INTEGER 4 bytes, in length. (Integers and Long Integers are also referred to "Words" and "Double Words", respectively). As an illustration, assume a dBASE database file is being viewed: The record count is stored in the file as a 4-byte unsigned long; instead of having to manually figure out what the 4 bytes in the file add up to, it is only necessary to position the cursor to the correct byte in the header area of the database file, then check the top of the screen and note the value shown for the "Unsigned Long". (Please refer to the detailed discussion of dBASE database files at the end of this documentation). To summarize, FX derives the values for the Byte, Integer and Long Integer as follows: BYTE: The value of the single byte at the current file (cursor) position. INTEGER: The integer value of the pair of bytes at the current file position; the first byte being the one at the cursor, and the second byte the one after that. LONG: The LONG (4 byte) integer at the current file position, the first byte being the byte under at cursor, followed by the next 3. _________________________________________________________________ (C) 1990, William Noble Page 22 FX User Documentation Version 1.1 _________________________________________________________________ For reference, the signed and unsigned decimal ranges of these values are as follows: UNSIGNED SIGNED Min Max Min Max --- ------------- --------------- -------------- BYTE 0 +255 -128 +127 INTEGER 0 +65,535 -32,768 +32,767 LONG 0 +4,294,967,295 -2,147,483,648 +2,147,483,647 For example, given the same sample file position, each of these displays would appear as follows as F8 was pressed: Decimal: U Byte:13 S Byte:13 U Int :48653 S Int :-16883 U Long:2298789389 S Long:-1996177907 Hexadecimal: H Byte:0dH E Int :be0dH X Long:8904be0dH Binary: B MSB--7654321076543210--LSB I Byte: 00001101 N Int :1011111000001101 If DECIMAL display is selected, two columns of numbers will be shown: the left column is the UNSIGNED value of the number at the current cursor position, and the right column is the SIGNED value. An unsigned number cannot be negative by definition, and all 8 bits in each byte are numerically significant. A signed number, on the other hand, CAN be negative, because the high-order bit is NOT used for its value but as the "sign bit": if the sign bit is 0, the number is positive, and if it is 1 the number is negative. (Negative signed numbers are represented in their two's compliment form. The binary form of a negative number-- its two's compliment-- is found by taking the positive form, reversing each bit, then adding 1. More won't be said about this, except that FX does this conversion automatically). Please understand that the issue of signed versus unsigned numbers is only one of INTERPRETATION- a byte is not intrinsically signed or unsigned, but only becomes so when one decides to use the high-order bit as a flag instead of for its binary value. If HEX display is selected, there is only one column: The unsigned Hexadecimal (base 16) value of the byte, integer, and long integer at the current file position. _________________________________________________________________ (C) 1990, William Noble Page 23 FX User Documentation Version 1.1 _________________________________________________________________ The BINARY display shows only the byte and integer- not the long integer. The "Least Significant Bit" position, (LSB), is at the right of the value, and the "Most Significant Bit" position (MSB) is to the left. This means that the right- most bit has a weight of 1, then progresses to 2, 4, 8, 16, 32, etc., moving from right to left. Above the byte and integer values is displayed the bit positions, numbered from 0 to 7. (Binary display reflects the unsigned value, NOT the two's compliment). Toggling Hexadecimal Status Line Notation ("H") Since it is often necessary to work both in terms of decimal and hexadecimal notation, FX is able to toggle its status line display between these two representations. Since it is assumed that pressing "H" indicates a desire to "think hexadecimal", this will ALSO cause hexadecimal notation to be used for the column of record offsets displayed to the left of the file display for Display Mode number 1 (ASCII). Only mode #1 is affected, since the other six modes will use decimal or hexadecimal implicitly. In addition, file positions reported by the LOCATE/COUNT/NEXT functions are affected by this toggle. When hexadecimal notation is toggled ON, the message "Hex Notation" will appear on the bottom right of the box enclosing the file display. Optimizing the Display for ".DBF" Files ("D") Since it is often necessary to investigate dBASE compatible database files, FX has a feature that facilitates their display in the FX File Window. Pressing "D" invokes a menu with 3 options: DATA, FIELDS and NORMAL. If one selects "DATA", FX will automatically determine where in the database the actual data (records) begin, and also the record size. FX will then automatically set the StartByte and the RecSize to these values. Further, the TAB amount is set to equal the record size, so each press of TAB advances one record. If one selects "FIELDS", FX will optimize its display to show the database field definitions from the header area of the database. This is the same for all databases: the field definitions begin at byte 32, each definition requiring 32 bytes. Again, the StartByte, RecSize and TAB are automatically set by FX. _________________________________________________________________ (C) 1990, William Noble Page 24 FX User Documentation Version 1.1 _________________________________________________________________ The NORMAL option does nothing more than set StartByte to 0, RecSize to 72 (the width of the display window), and TAB to 5. Since FX might potentially be used to repair damaged database files, it will allow the above options to be invoked even though the first byte in the file is other than decimal 2, 3 or 131 for dBASE III databases. (See discussion on databases later on). It will, however, display a warning message. Also, if the values found from the file don't make sense, (E.g. the header area of the file indicated a record size that is larger than the over-all file size!), FX will display a message and not take further action. Also, FX doesn't care whether or not the file has the ".DBF" extension. Please refer to the discussion of database files at the end of this manual for more information about database file structures. _________________________________________________________________ (C) 1990, William Noble Page 25 FX User Documentation Version 1.1 _________________________________________________________________ Understanding The FX Display FX displays files in terms of lines (records) in the File Window, each containing the number of bytes as defined for the "RECSIZE" value. (The last line of a file may contain fewer bytes if the record size is not evenly divisible into the file size). FX supports horizontally scrolling, if necessary, and an arrow will appear on the left or right of the top line of the edit box to indicate that data exists outside the display area. Each row in the window is accompanied by a number to its left outside the box border, which is the byte in the file at which the line (record) begins. Note that these values will remain the same even if the data in the window is scrolled to the right or left. These numbers on the left will always be displayed in accord with the current display mode (F1-F7). For instance, the "F7" mode uses three screen rows per record: ASCII, hexadecimal and decimal. Therefore, the numbers to the left of each row will be expressed in decimal, hexadecimal and decimal respectively. At the top-center of the screen is the numeric display, which has already been described in detail. The last 2 lines on the screen display file information and various counters that describe the current file position in a number of ways. Please familiarize yourself with their meaning! For reference, these lines appear as follows when FX is started: Byte: / Record: 1/0 Recbyte: # Modified: 0 File: StartByte:0 Recsize:72 Tab:5 The values on these two status lines can be displayed in either decimal or hexadecimal; this is done by pressing "H" to toggle hexadecimal notation on/off. The current byte is displayed in a reverse video block ("Cell") in the File Window, the size of which changes depending on the current display mode. The number of bytes that fit in the window also changes with the display mode- for instance, since decimal representation requires 3 times the width of plain ASCII, one- third as many bytes will fit in the window, and horizontal scrolling may be necessary to view the other bytes. _________________________________________________________________ (C) 1990, William Noble Page 26 FX User Documentation Version 1.1 _________________________________________________________________ StartByte ("S") The Startbyte is that byte in the file at which FX will begin displaying its contents, and defaults to 0 (first byte in file). This is useful in cases where a file begins with a header area that one does not want on the display; one can "focus in" on just the data portion that follows it. Recall that if the StartByte is not 0 (start of file), both LOCATE and COUNT will begin at StartByte, not the physical start of file. This value can be modified by pressing "S". Also, a section of the file might want to be viewed with a special record size, and setting the Startbyte to this section will allow FX to establish its logical records "in sync" with the data. (See the section "Using the Numeric Entry Box" near the beginning of the documentation for full details on entering numbers). Recsize ("R") The Recsize (Record Size) is the number of bytes FX places on each display line. This value defaults to the window size, (72 bytes), and can be modified by pressing "R". Since FX scrolls horizontally, the Recsize can be much larger than the width of the display window-- up to about 3,600 bytes per record. The Recsize can be very useful when used in conjunction with the StartByte. For instance, consider the case of a dBASE database file. The byte at which data begins can be found in the header portion of the database, as well as the record size in bytes. Armed with this information, the StartByte can be set to the byte where data begins, and Recsize can be set to the dbase record size. This will result in a "browse" of the records in the database, one record per line, except that the display is in FX format, so EVERY byte in the record is visible! (See the section "Using the Numeric Entry Box" near the beginning of the documentation for full details on entering numbers). _________________________________________________________________ (C) 1990, William Noble Page 27 FX User Documentation Version 1.1 _________________________________________________________________ Tab Amount ("T") The last value on the last line is the Tab Amount, and is the number of bytes FX will advance or back up when TAB or SHIFT-TAB are pressed. This value defaults to 5, and can be modified by pressing "T". Again referring to the above database example, the tab amount can be set to equal the database record size, so each press of TAB will advance one record, and each press of SHIFT-TAB will go back one record, even if the FX record size differs from the dBASE record size. (See the section "Using the Numeric Entry Box" near the beginning of the documentation for full details on entering numbers). File Byte The next to last line is in reverse-video, and displays the current position in the file from a number of viewpoints. The first field, "Byte:", ALWAYS reflects the current absolute position in the file as an offset from 0. Note that FX always considers the first byte in any file to be byte 0 (zero). This is in keeping with DOS conventions. The value to the right of the slash ("/") is the file size as recorded by DOS. Note that since all files begin numbering at byte 0, the last byte in the file will always be displayed here as one less than the file size! Record The number of bytes that FX places on each line is the number defined as the Record Size (modified by pressing "R"), and defaults to the window size, 72 bytes. Each line (composed of 1-3 physical rows) in the FX display is considered to be a record, and FX reckons records as starting from 1 (one), NOT 0. Therefore, the record counter is much like a line counter in a word processing program. Its important to note that records start numbering FROM THE STARTBYTE VALUE. This means that if the StartByte has been set greater than zero, then record numbering will begin with 1 at that point, and increase from there. This counter is of use when viewing database files, for instance, and if the STARTBYTE and RECSIZE are set properly will exactly reflect the database record number. Recall that the record size can be much larger than the window dimensions- up to about 3,600 bytes, in fact. _________________________________________________________________ (C) 1990, William Noble Page 28 FX User Documentation Version 1.1 _________________________________________________________________ If the record size specified is not evenly divisible into the number of bytes in the file, (or, if StartByte is not 0 then the number of bytes from the StartByte value to the end of the file), the last line will show a record number one greater than the upper-limit displayed, for example, "Record 551/550". This is intentional. Recbyte This is the byte offset into the current record, with the first byte of a record being 0. This is again handy for database files and the such, when one knows the byte offsets of certain fields within a record. Modified Displays the number of bytes in the file that have been changed by the user. This counter is reset to 0 whenever a new file is selected. _________________________________________________________________ (C) 1990, William Noble Page 29 FX User Documentation Version 1.1 _________________________________________________________________ Using FX with dBASE database files This section is meant to serve not only as a guide to dBASE database file structure, but also as the basis for a sample session. Also, the information below could be useful in "re- constructing" damaged database files! So start up FX, load any database file, and follow along. (Needless to say, if you intend to alter any bytes in the file, PLEASE DO SO WITH A COPY, AND NOT THE ORIGINAL!). dBASE databases are composed of 2 main areas: (1) The header area, which contains information about the database, such as the number of records, date of last update, and the field definitions. (2) The actual data immediately follows the header area. Every record is the same size, independent of how much data is stored in it. The bytes in the header area have the following meaning. (The byte numbers given are from the start of the file; that is, they will correspond to the "Byte:" display on the next to last line). Byte 0: dBASE III version number. Can have one of three values (shown here in decimal): 2=dBASE II file, 3=dBASE III file, or 131=dBASE III file with a Memo field. (This byte is bit mapped in dBASE IV). Byte 1: Year of last edit date. Byte 2: Month of last edit date. Byte 3: Day of last edit date. Bytes 4-7: Number of records in the database. (Long Integer). Bytes 8-9: Length of the header area in bytes (Integer). Note that this is ALSO the file position where the data actually begins in the file! Bytes 10-11: The record size in bytes (Integer). Bytes 12-31: Reserved, and therefore not very interesting. Byte 32-?? Fields are defined. There will be 32 bytes used to describe each field, for as many fields as necessary. _________________________________________________________________ (C) 1990, William Noble Page 30 FX User Documentation Version 1.1 _________________________________________________________________ Examining the field definitions To isolate the field definitions: 1) Set StartByte to 32 bytes. 2) Set RecSize to 32 bytes. Each line will contain a full field definition, the format of which follows. (The values are OFFSETS from the start of each field entry). Bytes 0-10 The field name, 1-10 characters, zero-filled. (E.g. C-style "Null-terminated" string). Byte 11 The field type: C, N, L, D, or M. Bytes 12-15 Field data address. Of no interest to us. Byte 16 Field length. Byte 17 Number of decimals. Bytes 18-31 Reserved. Note that the "RecByte" counter on the bottom is quite handy here: it displays how many bytes one is offset into the CURRENT RECORD. (The first byte of any record is 0). For example, to position the cursor at the field's FIELD LENGTH byte, just move until RecByte equals 16. _________________________________________________________________ (C) 1990, William Noble Page 31 FX User Documentation Version 1.1 _________________________________________________________________ Examining the data 1) Position the cursor to byte 8 and read the UNSIGNED INT value in the upper-left of the screen. This is the size in bytes of the header area. 2) Position the cursor at byte 10 and read the UNSIGNED INT value from the upper-left corner of the screen. This is the record size. 3) Set the StartByte to the value found in step (1), so that FX will start displaying the file at this point. 4) Set the RecSize to the value found in step (2), so that FX will format one database record per one display line. Of course, one could also just press "D" and have FX do all this itself, but, then, where's that sense of adventure? NOTE: All deleted records contain an asterisk (*) in the first byte of the record, (and therefore the first display column, RecByte=0), and normal records will contain a space (32 decimal or 20H hexadecimal) at this position. One can easily mark records as deleted, and "un"-delete them, using FX. Also, please observe that any data changed using FX that alters the value of fields used in an associated INDEX FILE may render the index file outdated, so always REINDEX after any changes to key field values made with FX! _________________________________________________________________ (C) 1990, William Noble Page 32 FX User Documentation Version 1.1 _________________________________________________________________ Summary of FX Messages 1) Memory-Related Error Messages: One of the following messages may occur if there is insufficient memory for fX to carry out certain tasks: "Not enough memory for primary i/o buffer." There was insufficient memory to allocate this essential buffer, and FX will therefore exit to DOS. Free up some memory and try running FX again. "Not enough memory to save screen contents." FX was unable to obtain enough memory to save the current screen contents prior to displaying the ERROR box. "Not enough memory for Save Screen buffer." FX was unable to obtain enough memory to save the current screen contents prior to displaying the HELP screen. "Not enough memory for screen/locate buffer." FX allocates 8K for the search buffer when it first starts. If it can't find the available memory for this required buffer, it will exit to DOS at once. "Out of memory: Exiting to DOS." FX could not find enough memory to build the file list when the select file ("F") option was invoked. 2) File-Related Error Messages: The following error messages may occur if the file being examined is damaged, or exists on damaged portions of the disk: "Error accessing this file byte!" FX was unable to seek to a certain file position. If this message appears, the file is probably on a damaged portion of the disk. "Error closing File. Exiting to DOS..." FX was unable to close the file; since having open files hanging around is not generally a good idea, FX will immediately exit under these circumstances. "Error seeking to starting byte." FX was unable to seek to the start of the file. "Error writing byte." There was an error writing the byte to the file. _________________________________________________________________ (C) 1990, William Noble Page 33 FX User Documentation Version 1.1 _________________________________________________________________ "The file being examined no longer exists! Exiting to DOS..." After returning from the DOS Shell, FX found that the file that was being examined is no longer accessible, probably because the user deleted this file while in the DOS Shell. "WARNING: Error flushing buffers: Cannot get a duplicate handle." FX was unable to flush the file buffers to disk after a byte was modified. "WARNING: Error flushing buffers: Cannot close duplicate handle." FX was unable to commit a modified byte to the file. 3) Status Messages "Byte successfully written." Confirms that a modified byte was successfully written to the file. "Cannot Edit bytes when in ALPHA-NUMERIC mode." An attempt was made to modify a byte by pressing CONTROL- ENTER when the "PURE-ALPHA" display option was enabled. Press "A" again to toggle this mode off, then modify the byte in question. "No File is Selected..." This message appears in a shaded box in the File Window if no file is selected. Since no FX feature can be used without a file selected, either press "F" to select a file, or ESCAPE to exit the program. "No more occurrences found." Appears when NEXT is invoked, and no more occurrences of the byte pattern were found in the file after the current file position. "nnnn Occurrences found." Report of total occurrences found after COUNT was invoked. "Please select a FILE to examine." The user tried to invoke an option before selecting a file. "Value is out of range." The value entered for the StartByte, TabAmount, RecSize or Jump byte was out of range. 4) Database Messages: The following messages may occur when the DATABASE option is invoked ("D"): _________________________________________________________________ (C) 1990, William Noble Page 34 FX User Documentation Version 1.1 _________________________________________________________________ "File is under 32 bytes in size. Cannot be database!" It is theoretically impossible for a database file to be under 32 bytes in length. "File size must be over 32 bytes for data to be present." An attempt was made to examine the data in a file of less than 33 bytes. "Note: The first file byte NOT 2, 3 or 131. Possible dBASE IV file." The first byte of all valid dBASE III database files is either 2, 3, or 131. FX is simply reporting that this is not the case for the current file. "Record size exceeds maximum line size." The database record size as read from the file exceeds the maximum allowed by FX, about 3,600 bytes. "The header size is impossible for this file!" FX read the stored Header Size and Record Size from the database header area, and found that (1) The header size is larger than the over-all file size, or (2) The record size is larger than the file size. 5) DOS Shell Messages: One of the following messages may occur when the DOS Shell option is invoked (Alt-D): "Cannot find COMMAND.COM!" FX could not find the command processor, "COMMAND.COM". Check that the COMSPEC environment variable correctly specifies the full pathname of this file. (This is usually done in the "AUTOEXEC.BAT" file). "Insufficient memory to invoke DOS Shell." There is not enough memory to load the command processor. If this message occurs, try to free up some memory (unload memory resident programs, etc.) and try again. "The COMMAND.COM file has invalid format." The "COMMAND.COM" file is, for some reason, not executable. _________________________________________________________________ (C) 1990, William Noble Page 35 FX User Documentation Version 1.1 _________________________________________________________________ Error Handling In order to be as robust as possible, FX takes over the hardware error handler, interrupt 24H. The upshot of this is that the message "Abort, Retry, Fail" will never appear while FX is running. Instead, in the event of an error, FX will pop-up a special box informing the user of the nature of the problem. The possible errors reported by FX are as follows: Bad Structure Length CRC Error Drive Not Ready General Failure Printer out of Paper Read Fault Sector Not Found Seek Error Unknown Command Unknown Media Type Unknown Unit Write Fault Write Protect Apart from the "Write Protect" and "Drive Not Ready" errors, the chances of one of these errors occurring very often in the context of FX is practically nil, unless, of course, one is using one's floppy disks for coasters. For more information on the import of the above errors, please consult a DOS manual. The interesting and important aspect of this, however, is that FX CAN handle damaged files, literally "stepping through" corrupt sections of a file to valid sections. FX will always issue a warning when an I/O error has occurred, allowing the user to ABORT FX or simply ignore the error. If IGNORE is selected, any lines that contain unreadable areas of the file will be replaced with FLASHING ASTERISKS. In addition, if it is suspected that a file contains damaged sections, or it is desired to locate those sections, this may be easily accomplished by simply pressing the PgDn key when in the File window to page through the file. If there is any problem with the file, then the error box will pop up alerting one to the situation, and lines containing errors will be blinking. This is an extremely powerful feature. _________________________________________________________________ (C) 1990, William Noble Page 36 FX User Documentation Version 1.1 _________________________________________________________________ FX Command Summary ESCAPE or X Quit FX and return to DOS. / Invoke the FX options menu. Positioning the cursor when in the File Window ---------------------------------------------- Up Arrow Previous record Down Arrow Next record Left Arrow Previous byte in record Right Arrow Next byte in record ENTER First byte in next record Shift + ENTER First byte in previous record ALT + Left Arrow Jump to first byte in record ALT + Right Arrow Jump to last byte in record HOME Jump to left edge of File Window END Jump to right edge of File Window PGUP Previous screenful PGDN Next screenful Control + PGUP Jump to first record (Top of file) Control + PGDN Jump to last record (Bottom of file) Control + HOME Jump to first file byte (StartByte) Control + END Jump to last byte in the file Tab Move forward by tab amount Shift + Tab Move backward by tab amount F9 Pan Left by 1/2 window F10 Pan Right by 1/2 window Keys that modify the display ---------------------------- A Toggle PURE ALPHA MODE. D Optimize the display for ".DBF" files. H Toggle hexadecimal status line notation. F1-F7 Select a display mode 1 through 7. [F1-F7] Set file's display mode AND adjust "RecSize" so that each file record fits exactly in the display window for the given mode. F8 Cycle through the numeric display options Dec-Hex-Bin-None. Keys that invoke FX functions ----------------------------- C Count occurrences of byte patterns F Select file J Jump directly to the specified file byte L Locate byte/text pattern N Locate next occurrence R Specify record size S Specify starting display byte ALT-S Set StartByte at cursor position. T Specify tab amount CONTROL + ENTER Modify current byte Alt-D DOS Shell _________________________________________________________________ (C) 1990, William Noble Page 37 FX User Documentation Version 1.1 _________________________________________________________________ Notes 1) Fx can easily handle very large files, but for files over 999,999 bytes, the display of the byte offset of each record that is placed to the left of the File Window will over-write the box border. This is NOT a bug. The width of the File Window (72 columns) was chosen because 72 is evenly divisible by 1, 2 and 3, allowing all display modes to evenly fill the window, but leaving only 6 free columns to the left of the box. The next smallest number divisible by 1, 2 and 3 is 66, which was judged unacceptably smaller. 2) Note on Vertical Scrolling: FX is optimized to traverse files by "screenfuls", using PgUp and PgDn. The display will, however, scroll one line at a time up or down when expected- When Up Arrow is pressed and the cursor is on the first line of the window, or when Down Arrow is pressed and the cursor is on the last line of the window. However, what really occurs in this case is more of a "shift" in the window on the file than an actual scroll, since a full screen of data is completely re- loaded. This was a conscious design decision to ensure that, without fail, the current display perfectly mirrors the underlying file and, further, that the cursor is perfectly synchronized with its position both on the display and in the underlying file. This may result in sluggish line-by-line scrolling when examining files on floppy disks or very slow hard disks, in which case PgUp and PgDn would be preferable for paging through the file quickly. ______________________________________________ FX was coded entirely in C and assembly language, using the Microsoft C Optimizing Compiler version 5.1, and Turbo Assembler (TASM) 2.0; it consists of about 8,000 lines of C source code, and 1,500 lines of assembler. (This is not necessarily an endorsement of these products, but is mentioned for those who may be interested). This is the second release of FX-- Version 1.1 ______________________________________________ If you have special file formats or requirements and think FX could be the basis for a useful utility in your environment, a proprietary version can easily be created for specific needs. We will gladly consider any proposals and quote pricing and terms for any ideas you have in mind. If you have any questions, technical difficulties, comments or suggestions of any kind, we would be quite delighted to hear from you! Please address all correspondence to: Far Darter Software, PO BOX 519, Closter, NJ 07624. (Registered users will be given priority attention). Due to limited time, we are unable to offer telephone support; however, registered users are welcome to include their phone number- if time allows and the situation recommends itself, we will get back to you by phone. _________________________________________________________________ (C) 1990, William Noble Page 38 FX Registration Information The registrations and licenses offered for FX (effective 12/1/90) are as follows: 1) A $15 registration fee is requested for the non- commercial, private use of the program. 2) $30 - Same as (1), but includes printed documentation and the latest version of FX. 3) In a business or government environment, a $35 license per user is mandatory. This license is for the perpetual, non-exclusive use of any version, and automatically includes the latest version of FX plus printed documentation. When registering for more than one user, please estimate the number of copies of the program you will use and refer to the following discount schedule: # Users License fee (Copies) per copy ------- -------------------- 1 $35 2-9 $30 10-24 $25 25-49 $20 50-99 $10 100-199 $5 Over 200 $1000 one-time fee, unlimited copies Independent of the number of users, you will receive one set of materials; you may then make as many copies as licensed. 4) FX can also be licensed on a per-server basis in a network environment, at $125 per network server, which allows FX to be installed on that one central location. Access in terms of number of nodes and number of users is unrestricted and UNLIMITED. If more than one local area network is involved, then additional licenses for each network server are required. This includes the latest version of FX and printed documentation; one set of materials will be sent. 5) Distribution Licenses and all other situations: Please contact the author. (Copying or using FX in any manner other than outlined above is prohibited). Please send all registrations, inquiries or comments to the address on the next page. We accept personal or company checks, money orders, or Visa, MasterCard or American Express. Sorry-- we don't handle purchase orders or invoicing. (Upgrades will be made available upon request). ***************************************************************** * Version 1.1 FX Registration Form Effective 12/1/90 * ***************************************************************** Please send to: Far Darter Software PO Box 519 Closter, NJ 07624 Limit of Liability: FX is distributed as-is. The author disclaims all warranties, expressed or implied. The author will assume no liability for damages either from the direct use of this product or as a consequence of the use of this product. Please register/license my copy of FX as: (Select one) (1) Single user basic registration @ $15.00 __________ (2) Single user "plus" registration @ $30.00 __________ (3) Business/Government: _____ users @ _____ = __________ (See discount schedule) (4) LAN, @ 125.00 per Server: _____ @ $125 = __________ Subtotal: __________ New Jersey residents add 6% sales tax + __________ Total: __________ Payment: [] Check [] Visa [] MasterCard [] American Express Card Number: ________________________________________________ Expiration date: ________________________________________________ Name: ________________________________________________________ Company: ________________________________________________________ Address: ________________________________________________________ City, State, Zip: _______________________________________________ Phone- Day: ______________________ Nite: _____________________ Signature: ______________________ Date: _____________________ Thanks for supporting Shareware! Index / FX Command Menu 2 /? Help listing switch 6 /A (Alpha mode character) switch 5 /A (Pure Alphanumeric display mode) switch 5 /H (Hex notation) switch 5 /J (Jump) switch 5 /M (Initial Display Mode) switch 5 /M (Initial Numeric Display Mode) switch 5 /Q (Quiet) switch 5 /R (Record Size) switch 6 /S (Start Byte) switch 6 /T (Tab Amount) switch 6 Alpha mode 13, 20, 34 ASCII In display modes 16, 20 Numeric Display notation 22 AUTOEXEC.BAT file 19, 35 Binary Numeric Display using 24 Bit 22 Byte 22 Byte location counter 28 Cell 26 Cell size 21 CGA monitors 3 Command line arguments 4 Command Summary 13, 37 COMMAND.COM file 19, 35 COMSPEC environment variable 19, 35 Counting byte patterns 18 Current directory 15 Current file location 28 Cursor size 21 Damaged files 36 Database files 30 DATABASE option Messages 34 Databases Displaying 24 Structure of 30 Decimal In display modes 16, 20 Numeric Display notation 22 Numeric Display using 23 Display mode 12, 26 Alpha-Numeric 20 Changing the 12, 20, 21 DOS Shell Error messages 35 Dos Shell option 13, 19 DOS version 3 Double Words 22 Editing keys 8 Error handling 36 Error messages File-related 33 Memory-related 33 File Selecting 15 File name Specifying on command line 5 File Window 10 File Window commands 13 Hardware Requirements 3 Help, invoking 2, 13 Hexadecimal In display modes 16, 20 Numeric Display notation 22 Numeric Display using 23 Status line notation 12, 13, 24 I/O Errors 36 Installation 4 Integer 22 LANs Registering FX for A Using FX on 3 Least Significant Bit (LSB) 22 Locating bytes 16 Long Integer 22 Memory requirements 3 Menus, using 8 Messages File-related 33 For DATABASE option 34 For DOS Shell option 34, 35 Memory-related 33 Status 34 Modified Display of 29 Modifying a byte 18 Monitor type 3 Most Significant Bit (MSB) 22 Mouse support 3 Network Registration A Network support 3 Numbers, entering 8 Numeric entry box 8 Numeric equivalent display 22 Options Menu 14 PATH environment variable 4 Pure Alpha mode 20 Quick start 2 Quitting FX 13 Recbyte 29 Record Display of 28 Offset into 29 Record size 27, 29 Default 10 Definition 10 RecSize 21, 24, 26 Modifying 27 Registration form B Registration Information A Scrolling 26 Vertical 38 SHARE program 3 Sign bit 23 Signed numbers 23 StartByte 17, 24, 27 Modifying 27 Starting file byte 27 Starting FX 2 Status messages 34 Tab amount, setting 28 Technical support 38 Two's compliment arithmetic 23 Unsigned numbers 23 Video mode 3 Word (2 byte integer) 22