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TVX Reference Manual This is the Reference Manual for TVX, a public domain screen editor written in C by Dr. Bruce E. Wampler. (Current address: Dr. Bruce E. Wampler, University of New Mexico, Department of Computer Science, Farris Engineering Center, Albuquerque, NM 87131). Any comments, bug reports, or suggestions should be sent to that address. This manual contains the formal descriptions for each editor command. An appendix gives some notes for installing TVX on various systems. The name TVX is derived from "TV" editor for any terminal ("X"). *** GETTING STARTED *** To edit a file using TVX, enter the following command line: tvx filename -switch1 -switch2 ... The file name specified is the file to be edited, and must obey the conventions used by the local operating system (the MS-DOS version requires DOS version 2.0, and supports pathnames). If the file is a new file (does not exist), TVX will ask if you really want to create it. Answer y or n. If you gave an incorrect name, you may give the correct name, but the switches entered on the original start line will remain in effect. Control-C can be used at this point to abort. TVX has several switches which control certain operating characteristics. Each switch begins with a minus (-), and is separated from the file name and other switches by a blank in the standard UNIX/C convention. Some switches may be negated by using a 'nox' form. Thus, '-b' will cause a .bak file to be generated, while a '-nob' causes the .bak file to be deleted on exit from the editor. This capability is indicated by []'s. As many switches as necessary or desired can be used at one time in any order. A ':' may be used instead of a '=' for '-c' and '-o'. The various switches supported include: -c=filename -- read a configuration file. If only -c is specified, TVX will look for A:CONFIG.TVX on CP/M and for /bin/CONFIG.TVX on MS-DOS. The -c switch is not supported on all implementations. -[no]b -- generate a .BAK version of the original (the usual default). The -nob option means no .BAK file is generated. This mode of operation follows the normal Unix convention of not keeping past generations of a file. -[no]i -- auto indent mode enabled. -[no]l -- generate BACKUP.LOG file -o=filename -- send edited output to filename. The output file can also be changed at any time during the editing session with the ':o' command. -r -- read only - file can be read in only -s -- big save buffer - leaves more buffer for save file -t -- tty mode - puts TVX into tty mode, not using the screen. -1- TVX Reference Manual 11/27/85 See the special appendix on tty mode. -w -- word processing mode - sets autowrap on, margin to 65. -z -- -z means use Control-Z to mark end of file, -noz means don't use. This switch is used only on MS-DOS implementations. -# -- entering a number from 3 up to the number of lines on the screen will create a smaller TVX editing window. This is most useful for slower baud rates. A -7 makes a nice, small window showing 7 lines. TVX is mostly a programmer's editor, and can can edit any standard text line file. On Unix systems, it is an alternative to standard editors such as ed or vi. On MS-DOS, TVX can also be used to edit standard BASIC programs. BASIC programs must be saved using the ",A" switch from Microsoft BASIC. When editing BASIC files, care must be taken to preserve the BASIC statement line numbers. On CP/M, TVX can be used as a totally compatible alternative to ED. Because of memory limitations, the CP/M version contains a subset of the commands available on the regular version. *** General Comments *** TVX functions almost identically for all versions. All commands are normally the same, although it is possible to create custom versions with a different command set. Control codes on are normally entered by pressing the CTRL key and the letter key at the same time. On most versions, the character delete key is BACKSPACE. This character delete keys is the one normally used by the respective operating systems. It is up to the local implementation to notify the user of any variance from these conventions. Once the file has been read in, the screen will be cleared, and the first screenful of the file printed on the screen and the cursor positioned over the first character of the file. If a new file is being created, the message "buffer empty" will be displayed, and the cursor positioned in the upper left corner. TVX is then ready to accept commands from the keyboard. TVX works on the principle that what you see is what you get. Most commands also take an optional numeric count. The default count is always one. Commands that allow a count value are preceded by the letter 'n' in the following descriptions. Whenever a command produces output or an error message, it appears on the bottom line of the screen. The BACKSPACE key (Control-H on some terminals) is used to edit input text. When TVX is accepting commands, BACKSPACE will cause the character immediately before the cursor to be deleted. The text from the file which is being edited is held in a buffer in main memory. If a file is particularly large, it may not entirely fit into main memory. The CP/M version of TVX allows slightly over 20,000 characters in the buffer (950 lines). The MS-DOS versions will allow up to almost 64K characters depending on the memory available. Unix versions will usually allow 120,000 characters and 5000 lines in one buffer. If the entire file will not fit into the buffer at once, then only part of it is read in at a time. The buffer size limit in -2- TVX Reference Manual 11/27/85 no way restricts the total size of a file that can be edited by TVX. To make editing large files easier, some commands apply to the entire file and cause automatic cross buffer manipulation. Because of the internal organization of the text within the buffer, TVX may occasionally "compact" the tiny fragments of unused buffer space generated as a part of normal editing. When this happens, a message is displayed, and input keystrokes are remembered but not echoed until the compaction process is complete. The process may take several seconds. While the normal screen is only 80 columns wide, TVX has been written to support a "virtual" screen width of 240 columns. As you move the cursor right on a line that is longer than 80 columns, the screen will automatically scroll to the left in increments of 16 columns. Note that on terminals that cannot disable auto wrap around for column 80, when you are making changes to a line that is longer that 80 columns, the line will wrap around to the next display line so that the entire line is visible. The wrap will disappear when you use the 'd' or 'u' commands, or rewrite the screen with the 'v' command. Most versions will not wrap long lines. A key to success when using TVX is to remember that there are two modes of operation. The normal mode is command mode. In this mode, all keystrokes are interpreted as commands. When you want to enter text, you must enter insert mode with the 'I' command. While in insert mode, all keystrokes entered will be inserted into the file and displayed on the screen. You must exit from insert mode with the escape key. When you enter insert mode, the message "### Insert Mode ###" will be displayed on the last line of the display. Also, on many terminals, TVX will change the cursor character between command and insert mode. TVX uses two techniques for protecting the original file from editing mistakes. First, each time a file is edited, a new version is created, and the previous version retained in its original form as a backup. This file will change the original file extension to '.BAK' on CP/M and MS-DOS systems, and '.B' on Unix. A more complete description of TVX file handling is included in an appendix. Also, as you edit your file, TVX has the capability to write all commands entered during the session to a log file when that capability is enabled. In the event of a major editing mistake, it is possible to edit that log file to remove the command errors, and then apply that "command" file to the previous version of the edited file to get back to the state right before the mistake. This feature also allows files of TVX commands to be defined by the user and executed in one step. The last section of the Reference Manual explains how to use the command file feature. -3- TVX Reference Manual 11/27/85 *** Summary of TVX Commands *** Notes: An n preceding a command means optional numeric argument may be supplied. If omitted n will default to 1, and n can be zero or negative if appropriate. '$' represents the escape key, and is used as a terminator for insert, find, and loops. Control commands are indicated with '^'. For example, '^K' represents Control-K, and is usually entered by simultaneously holding down the CTRL key and the K key. nA - Append to Save Buffer The 'A' command is used to append lines of text to the end of the save buffer, even if other commands have been used since the last 'A' or 'S' command. The append command works exactly like the 'S' command otherwise. B - Buffer beginning A 'B' causes the cursor to be moved to the beginning of the current buffer. ^B - Beginning of file The '^B' (Control-B) command is used to position the cursor to the absolute beginning of the file. The '^B' command will always write out the rest of the file, then re-read the first buffer full. This command has the side effect of making a new backup version of the file. It should be noted that any text saved in the save buffer will be preserved during this operation, so that the 'S' save command can be used to move text from the end to the beginning of a multi-buffer file. The search pattern and repeat loops are retained as well. Note the '^B' file beginning is similar in concept to 'B' buffer beginning. nC - Change 'C' can be used to change characters. Entering 'nC' is exactly equivalent to entering 'nKI'. The command will cause 'n' characters to be killed, and insert mode to be entered. The escape must be used to terminate the insert as usual. nD - Down 'D' moves the cursor down n lines. The cursor is placed at the beginning of the new line. For convenience, the ENTER key performs the identical function. -4- TVX Reference Manual 11/27/85 n^D - Down in column Control-D ('^D') is similar to 'D', except the cursor remains in the original column. Columns are defined as characters from the beginning of the line, so if a line has tab characters in it, the cursor may appear to move out of column on the screen. E - End of the buffer 'E' causes the cursor to be placed at the end of the current text buffer. n^E - Edit repeat buffer n When making repeat loops, it is easy to make a mistake. The ^E command allows any of the repeat buffers to be edited, and then the ^R command can save the corrected repeat buffer back. If you give a value 0 for n, the currently selected buffer is used. If n is from 1 to the maximum number of repeat buffers, then that repeat buffer will be selected for editing. The ^E command will insert the contents of the selected repeat buffer into the current text buffer. The repeat buffer will be inserted above the current text line. The repeat buffer will start with a sequence of '#n:<', where n will be replaced by the repeat buffer being edited. The '#n:' identifies which buffer you are editing, and is used by the ^R store repeat buffer command to identify the buffer to save to. Escapes will be represented by '^[' instead of the '$' used when entering a repeat buffer initially. A '>^[^[' identifies the end of the repeat loop. It is possible to make as many changes as needed to the repeat loop. Escapes can be added by using '27i'. If you want to save the loop in a different buffer, you can change the number after the '#'. It is also important to maintain the '#n:<' start and '>^[^[' ending sequences. Also, loops are limited to a maximum of 100 characters. You can have carriage returns within the body of a loop, too. If you want to create a new buffer, you can use ^E on an empty repeat buffer to get the required '#n:<>^[^[' loop sequence. After you have edited the repeat buffer, it can be saved with the '^R' command. You must place the cursor anywhere on the first line of the repeat buffer before using '^R'. When you press ^R, the buffer will be saved in the buffer indicated right after the '#'. Thus, unlike ^E, the ^R command accepts no n value. nF - Find text pattern 'F' is used to find a text pattern. When 'F' is entered, the message 'Find?' is echoed on the bottom line. You then enter the pattern to find, terminated with the escape key (echoed as $). When the count 'n' is positive (which is the default), find searches the -5- TVX Reference Manual 11/27/85 current buffer from the current position forward. If 'n' is negative, then a backwards search is performed starting with the previous line. (Use '^F' to search across buffers). Normally, 'F' ignores the case of the letters in the pattern. If the ':F' parameter is set with 0, then 'F' command will match only the exact case. See the ':' set parameter command for details of the ':F' parameter. If the pattern is not found, "Not found" will be printed and the cursor remain at its original location. If the pattern is found, then the cursor will be placed immediately following the pattern. The pattern may be at most 100 characters long. If the pattern is only an escape, then the previous pattern will be used again (same as ';'). TVX supports extensive wild card matching. The ':M' set parameter controls whether or not wild card matching is turned on. Normally, it is. The wild card matching in TVX is based on the concept of 'sets of special characters'. TVX predefines 6 sets of characters, and allows the user to define one additional set. When a special control character is included as part of the find pattern, then any character in the specified set will match the pattern. The predefined sets are: ^A - Alphanumeric characters: a-z, 0-9 ^D - Digits: 0-9 ^L - Letters: a-z ^O - Other characters: all characters except a-z, 0-9 ^P - Punctuation: '.', ',', '!', '?' ^X - Any character: any printable character ^U - User character: any character in user set, set by ':U' Any of the sets may be specified by entering the proper control character in the find pattern: Control-A for the ^A set. Thus, entering a find pattern of '^L^D' would match any letter followed by any digit. Since it may be desirable to match a sequence of one of the character sets, two prefix characters are supported. A '^W' before one of the above sets will match a 'word' of that set. Thus, '^W^L' will match any word, and '^N^D' will match any number. The find pattern 'st^W^L' would match words starting with 'st'. The '^N' prefix is used to make a 'word' of characters NOT included in the given set. Thus, '^N^L' will match a 'word' of characters NOT including the letters a-z. A match 'word' consists of any sequence of characters (at least one character long) found in the given set, up to the first character not in the set. End of lines also terminate all wild card patterns. The only real way to adequately understand TVX wild cards is to use them in practice. ^F- Find across buffers '^F' (Control-F) is the same as Find, except the search will cross buffer boundaries. Whenever a buffer is searched without finding the pattern, the next buffer will be read in. The screen will not change until the pattern is found or the file is exhausted. If the pattern is not found anywhere, then the entire file will have been written out, and there will be an empty buffer. The '^B' command may be used at that point to get back to the beginning of the file. -6- TVX Reference Manual 11/27/85 G - Get saved text 'G' is used with 'S' and '^Y' to move text around. 'G' causes the text in the save buffer to be inserted before the current cursor position. The saved text remains in the save buffer. There must be at least one line of text in the main buffer before 'G' will get the text from the save buffer. ^G - Get killed line (unkill) The '^G' (Control-G) unkill command can be used to "unkill" one line, which will be the last line killed with '^K'. If the last command was 10^K (kill 10 lines), then '^G' will retrieve only the last line killed. The "unkilled" line will be inserted right before the current cursor position. It is also possible to move single lines around the text buffer using '^K' and '^G' - but be cautious. Any other '^K' command will reset the last killed line. '^G' can also be used to retrieve the entire line involved in a "'" (single quote) or '"' (double quote) command. nH - Half page 'H' is similar to the 'P' Page command. It causes the cursor to move down a half screenful. This will be typically be 12 lines. A negative count (e.g. -h) moves up a half screen. nI - Insert 'I' causes the editor leave command mode and enter insert mode. Following the 'I', all text typed in is inserted into the file until a terminating escape is typed. Inserted text is echoed on the screen as it is inserted. If any value other than the default value 1 is supplied for n, then only one character is inserted, and it will have the ascii value of n. This is the method used to enter characters that cannot normally be entered in insert mode, such as escape or characters not on the keyboard. The message "### Insert Mode ###" is displayed on the bottom line when insert mode is entered (except when inserting on the very last line of the file). Many versions of TVX will change the shape of the cursor when insert mode is entered. J - Jump back The 'J' command will cause a "jump" back to the line of the previous cursor position. Suppose the cursor was positioned somewhere in the middle of the file. If the 'E' end command was entered, the cursor would move to the end of the current buffer. If the 'J' command was then used, the cursor would return to the original line. It makes it convenient to flip back and forth between two points in the file. It is also useful if a large cursor movement command is accidentally entered (like when you thought you were in insert mode). -7- TVX Reference Manual 11/27/85 nK - Kill Character forward The 'K' command kills or deletes characters in a forward direction. '1K' would delete the character the cursor is positioned over, and '5K' would delete the next 5 characters. n^K - Kill lines '^K' (Control-K) is used to kill an entire line. n=1 kills the current line, negative n kills previous lines, while positive n kills following lines. nL - Left 'L' moves the cursor n characters to the left. M - Memory and Status The 'M' command is used to display certain status information. The name of the file currently being edited (where the output will go) is displayed, followed by the version of TVX. The number of free characters currently available in the buffer is then given (this does not include characters that are free but not compacted yet), followed by the number of the last line of the file. Finally, the currently selected repeat loop buffer and maximum number of repeat buffers allowed is shown. nN - Note current location This command notes the current line location. Values of 1 to 9 are allowed for n. After entering '3n' for example, you can then move around the buffer, and later use '3^n' to return to the noted location. This command really remembers the current line, relative to the current buffer beginning. Thus if you edit out lines before the noted location, you will not return to the same line. n^N - Go back to noted location This command is used to go back to a noted location. nO - Open line for insert The 'O' command will cause n blank lines to be inserted, and the cursor positioned at the beginning of the first new line. Following the 'O' command, insert mode is automatically entered. The 'O' command is a convenient method for inserting new lines. -8- TVX Reference Manual 11/27/85 ^O - Operating System call Some versions of TVX (MS-DOS and Unix, for example), will allow an operating system command to be executed from inside of the editor. For example, it might be useful to get a directory listing. On MS-DOS, after entering the ^O, the normal 'dir' command is entered. After the directory is shown by the operating system, pressing any key will return to the edited file. This command has one particularly valuable application - editing other files. For example, you may want to add part of another file to the file you are currently editing. Use the '^O' command to edit the other file, and create a temporary file with the part you want to add. Then you can use the '^Y' yank command to read in the file. For example: Use '^O' to get enter operating system command prompt. Then enter something like 'tvx otherfile -o=tempfile'. You will get a new copy of tvx with the otherfile being edited. Edit it to get the part you want. When you exit that copy of tvx, the part you want to add will be in tempfile. You can now yank it into the current file. nP - Page The 'P' commands is the same as '25D' on 24 line terminals, and effectively causes a new screenful to be written. It is a convenient method for scanning through the file. The n count argument specifies the number of 'pages' to scroll. Negative values for n causes reverse scrolling. ^P - Print Screen If '^P' (Control-P) is entered, and a printer is on line, the entire contents of the screen will be sent to the printer. Several consecutive sequences of "P^PP^P..." (or a repeat loop: "10<P^P>$$") can be used to print longer portions of the file. This command will not normally work on time shared systems such as Unix. nR - Right 'R' causes the cursor to move n characters to the right. For convenience, the space bar is equivalent to 'R'. ^R - Restore repeat buffer The '^R' command will save an edited repeat buffer and delete the edited buffer from the text. See '^E' for a complete summary of editing repeat buffers. nS - Save text Besides the normal text buffer, TVX has a separate "save" buffer. This buffer can be used to move blocks of text from one part of the file to another. A simple 'S' command will save the current -9- TVX Reference Manual 11/27/85 line in the save buffer, and move the cursor down one line. On the screen, 'S' appears to have the same behavior as 'D'. If n is supplied, then n lines will be saved. 'S' can also be used sequentially. If no other commands intervene, consecutive 'S' commands will continue adding lines to the save buffer. If any other commands are entered between consecutive 'S' commands, the previous contents of the save buffer will be lost, and replaced with the new line. The 'A' command can be used to append lines to the current save buffer without losing the previous contents. The '/' command can be used with 'S' and 'G' to move text. Use 'S' to save the text to be moved, immediately delete the saved text with '/', then insert it at the new place with 'G'. The last line of the file is can be saved in the save buffer only once, and an error message will be printed if you attempt to save the last line a second time. nT - Tidy text The 'T' tidy command is specifically designed to improve the appearance of strictly text files. When entering letters and documents, is it usually desirable to have the lines filled to the right margin. However, after editing, it is common to find a jumble of uneven, difficult to read source lines. The 'T' tidy command will fill source text using the same right margin currently set for auto-wrap. Tidy performs essentially the same operation as a word processor fill function. Word are combined on one line until the auto-wrap margin is passed. The 'n' count refers to the total number of resulting lines, not the number of original lines. Specifying a large 'n' will tidy large sections of a document. The tidy command recognizes lines beginning with blanks,tabs, or a period and blank lines as special. It will not fill those lines, thus preserving paragraphs, tables and NROFF-like dot commands. One interesting capability of tidy is to put one word per source line. Set the auto-wrap margin to 2, then use the tidy command. The result will put one word per line. ^T - TERMINATE - ABORT EDIT SESSION The '^T' (Control-T) command aborts directly to the operating system. The original file is left untouched, and no backup file is created. This is a fairly dangerous command in that all editing performed will be lost (unless the '^B' file beginning command was used). You will be asked to confirm the '^T' command with a Y or N. If the '^T' is performed accidentally, the backup log file can be applied to the current version of the file after the '^T' has been edited out of the log file (no backup file will have been created after the '^T'). The '^T' command is most useful when you decide you don't want to make any changes and want to exit from TVX quickly. Exiting with the '^T' command is similar to using the 'R' read only switch at the beginning. If you have used the '^B' command, a work file copy of the original will have been written out containing all the edits performed before the '^B'. When you use '^T' and this work file has been saved, -10- TVX Reference Manual 11/27/85 a message informing you of its existence will be printed. You can then either use that file, or delete it at the operating system level. nU - Up The 'U' command moves the cursor up n lines, positioning the cursor at the beginning of the line. n^U - Up in column The '^U' (Control-U) is the opposite of '^D', and moves the cursor up in column. nV - Verify the screen In regular screen editing mode, the 'V' command causes the screen to be rewritten. This is sometimes necessary to get a true version of the screen after error messages have been written or when editing lines longer than 80 columns. On terminals without reverse screen scroll, the 'V' command forces the cursor to the home display line (usually line 16). In screen mode, 'V' ignores any n. In tty mode, the 'V' command is used to type lines from the file on the terminal. A negative n will type out lines preceding the current line. An n of 1 types the current line, with the current cursor position indicated by '/'. An n greater than 1 types the current line, plus the following n-1 lines. A command '-12v12v' would type 24 lines on the terminal: 12 before, the current line, and 11 following. n^W - Write out buffer, read next one The '^W' (Control-W) command is used to explicitly go from one buffer to the next. By default, when n is >= 0, the entire current buffer is written to the new version of the file being edited, and the next buffer full of the original file (if any) is read in. If a negative n is supplied (any negative value, most easily -^W), then only the part of the buffer up to (but not including) the current line is written. Then as much more of the file as possible is read to the end of the current buffer. Thus, a negative n is useful when a file won't fit, and the split point is at an awkward place. It is also useful when a '^Y' yanked file won't fit. ^X - eXit '^X' (Control-X) causes the remainder of the file to be written out, and the editor exited. The entire file will be written, no matter where the cursor happens to be positioned when the '^X' command is entered. This is the normal conclusion of an editing session. All work files are deleted, the original file renamed to the back up file, and the newly edited file renamed to the original name. See the -11- TVX Reference Manual 11/27/85 appendix on tvx file handling conventions for more details. n^Y - Yank text to/from external file (file merge) A '^Y' (Control-Y) with a positive n is similar to 'S' save, but the text saved in the save buffer is read in from an external file instead of from the current buffer. When '^Y' is entered, the save buffer is cleared, the buffer compactor invoked, and then the user is prompted for the name of the file to read. TVX then will read as much of the external file into the save buffer as it can. The 'G' command can then be used to insert the save buffer text into the current file at the desired location. If there is not enough room in the save buffer to hold the entire file, then only part of the file is read and a diagnostic message printed. The '-S' switch can be used when TVX is first invoked to reserve a large save buffer for merging larger files. You can also use the '-^W' command to write out the front part of the file, and then 'G' to get the saved file. (Note: '^Y' may not be used from within a log command file. See section on backup log file.) A negative n (e.g., '-^Y') can also be used with the yank command. If the n is negative, then the contents of the save buffer will be written to a new file. After '-^Y' is entered, you will be prompted for the name of the output file, and then the contents of the save buffer will be written to that file. nBACKSPACE - Delete previous character The BACKSPACE key will delete the previous character on the screen. It is also used for editing input keystrokes for Insert, Find, and repeat loops. n; - Find again The ';' (semicolon) command causes the previous pattern to be searched for again. This is more convenient that entering 'F$' again. The 'n' has the same meaning, positive searches forwards, negative backwards. / - delete last thing The '/' (slash) command is useful when used with 'F' (find), 'S' (save), 'G' (get), 'TAB' (word right), and '{' (word left). It causes the last pattern used to be deleted. Thus "Fxxx$/Iyyzz$" will delete the pattern 'xxx' and insert 'yyzz'. When used after an 'S', it causes the just saved lines to be deleted from the text buffer (but not the save buffer). After the G, it causes the text just inserted from the save buffer to be deleted from the text buffer. After a 'TAB' or '{', '/' will delete the word or words just skipped over. Slash must be used immediately following an 'S', 'G', 'TAB', '{', 'F', '^F', or ';' command. This command knows how to take wild card matches into account. -12- TVX Reference Manual 11/27/85 = - delete last thing and enter insert mode The '=' (equals) command is the same as the '/' command, except insert mode is automatically, thus achieving the effect of '/I' command sequence. ' - Delete previous part of line (single quote) The "'" command will delete all the characters in the current line before the cursor. " - Delete rest of line (double quote) The '"' command will delete from the cursor forward to the end of the line. The "end of line" mark will remain. Note that the single quote has one tick, representing the "first" part of the line, while the double quote has two ticks, representing the "second" part of the line. , - beginning of line (comma) The ',' command will move the cursor to the beginning of the current line. . - end of line (period) The '.' command will move the cursor to the end of the current line. * - Insert last pattern found The last pattern found with the find command (up to 100 characters) is saved in an internal buffer. The '*' command will insert that pattern into the text at the current cursor location. If the last find pattern included wild card characters, the pattern saved will be the actual text matched, and not the wild cards themselves. You must be back in command mode to use this command. nTAB, n{ - Skip over words The 'TAB' (TAB key, CTRL-I) and '{' commands skip over words. A word is any contiguous set of alphabetic characters (a-z) or digits (0-9). 'TAB' moves forwards, while '{' moves backwards. The 'n' count may be used to skip over several words at once, and a negative count reverses the direction of the move. Note that '{' is usually aliased to '[' since these are often reversed case on different terminals. -13- TVX Reference Manual 11/27/85 n< - begin repeat loop TVX has three different repeat loop buffers which allow an arbitrary sequence of commands to be repeatedly executed. When n< is typed, the editor echoes 'Repeat: n<' at the bottom of the screen. The user then types in any series of commands to be repeated n times. The repeat command is terminated with a matching '>' and a double escape (echoed as $$). Repeat loops may not be nested. The repeat loop has two typical useful functions: one is to replace multiple occurrences of a string with another (e.g., "10<fone$=two$>$$"), a second is to save a complicated sequence of commands to be repeated as necessary with the '&' command (i.e., a macro facility). Each repeat loop may have up to 100 characters. When a repeat loop is entered from the keyboard, it is saved in one of three repeat loop buffers, each identified by an integer value. The repeat buffer which is currently in use can be set with the 'n:R' command. Buffer 1 will be used by default. The number of repeat buffers available and the currently active one can be determined by using the 'M' command. The availability of three repeat buffers allows the definition of 'edit macros'. Commonly used sequences of editor commands can be saved in a given repeat buffer, then selected with 'n:R' and executed with the '&' command. For example, "3:R<fpat1$>$$" would select repeat buffer 3 and enter the repeat command into it (and execute the command once). Other "macros" could be entered in other buffers, and then the given example used again by "3:R&". A count 'n' of 0 can be used to enter a macro without executing it. The indirect command file facility ('@' command) can also be used to define and load commonly used macros. The results of using one repeat buffer from within another is not guaranteed, and should be tried only at your own risk. The '#' command has been provided to simplify the above sequence. Entering '23#4' for example, is exactly the same as entering '4:r23&'. The n value is a count, and the single digit after the '#' is the repeat buffer to use. >$$ - End of repeat loop The repeat loop is terminated by a '>' and a double escape. Note: '$$' represents escape. n& - execute repeat loop The '&' command executes the commands in the currently selected repeat buffer n times. n#k - execute repeat loop k This command is an easy to execute a specified repeat buffer. The n is a count and the k is a single digit repeat buffer number. This command is exactly equivalent to 'k:rn&'. Repeat buffer k becomes the current buffer after '#' is executed. -14- TVX Reference Manual 11/27/85 ? - Help The '?' command causes help screens do be displayed. There are two help screens. The first includes a summary of transitory values: a summary of settable ':' parameters, the contents of the repeat and find buffers, as well as buffer space left. On 16 or bit processors, if the space left is greater than 32,000 characters, then 30,000+x will be shown, where the total is 30,000 plus x. The first screen also shows the last 16 commands you have entered. This may be useful if you entered "commands" while you thought you were in insert mode to see what your keystrokes might have done. The second screen of help summarizes the command set. @ - Invoke command file Causes prompt for command file name. Commands in that file are then read in and executed. See description of backup command files below for details. n:P - Set special parameters The ':' (colon) command is used to set several TVX characteristics. The value n entered before the ':' is the value to set the parameter to, and the character P that follows the ':' defines the parameter to set. Valid parameters include: n:A - set autoindent. A value of 1 turns on autoindent, 0 off. Autoindent is useful for programmers. When autoindent is on, each new line started while in insert mode will be indented to the same leading tab/blank space as the previous line. Use blanks or tabs to add indentation, and backspace to backup over indentation. n:D - set home "display" line to n. The display line is the line the cursor homes to after a verify command. (Default home display line: 16 on 24 line terminals, 9 on 16 line terminals.) n:E - Expand tab value. The default value for ':E' is 8, which causes the tab character (^I) to be expanded to multiples of 8 columns. This is the standard used on most systems. Setting ':E' to 0 will cause tabs to be displayed as '^I' instead. Other values are possible, but less useful. n:F - Find case mode: n <= 0 sets find mode to search for exact case of pattern, n > 0 (default) set search mode to ignore upper/lower case. n:M - Match wild cards. (default=1). If on, then matching of the TVX wild card sets is enabled. If off, then the wild card control characters will match the actual control characters in the file. :o - set output file name. When ':o' is entered, you will be prompted for the name of the edited output file. This overrides the '-o' command line switch, and can be used to change your mind about the name of the edited file. If the output file name is different than -15- TVX Reference Manual 11/27/85 the input file name, the input file will not be renamed to the backup file name. n:R - select repeat buffer n. (default=1). Repeat buffer n becomes the current repeat buffer executed with the '&' command. The 'm' status command will show how many repeat buffers are available for a given implementation. n:S - scroll lines: This parameter sets how many lines the cursor will move before the screen scrolls. The exact effect of the scroll parameter depends on the terminal characteristics. On terminals that allow a blank line to be inserted at the top, ':S' sets how many lines cursor will move above and below home display line before scrolling. Default is 0. Changing the scroll value to 4 would let the cursor move up and down 4 lines from the home display line before actually scrolling the screen. Some users might find this update mode more pleasant to use. This will be almost essential on heavily loaded time shared systems. For terminals that do not allow a blank line to be inserted at the top (no reverse scroll), 'n:S' sets how many lines cursor will move above the home display line before the screen is rewritten. Default is 14, which causes the cursor to move nearly all the way to the top before rewriting the screen. n:T - tty mode. A 0 is screen mode, a 1 is tty mode. n:V - virtual window lines. The 'n:V' will set the virtual window to n lines. N must be between 3 and the number of hardware lines on the terminal. A smaller virtual window is extremely useful on busy time shared systems, or when TVX is used over a telephone line at a relatively slow baud rate. Typically, a virtual window of 7 or 9 is big enough to show a reasonable part of the file, yet small enough to reduce the overhead of screen update at slow speeds. A window of 3 or 5 can even be used if needed. Note that the virtual window can be set at start up time by using the '-#' switch. The virtual window will use the top n physical lines of the display. Error messages and prompts will still be displayed on the bottom physical line. Scanning up with 'u' will cause the lines to be scrolled onto the unused part of the screen, and gives a true picture of the file showing more lines than the window size. n:W - set auto wrap width. The ':W' parameter sets the column number used for auto wrap mode. When the auto wrap is set to a value greater that 1, TVX will automatically insert an end of line when the user types the first blank after the given column. Normally, the user must manually hit the RETURN key to force an end of line. The auto wrap mode allows continuous entry of text without worrying about the right margin. A good value to use for ':W' is 10 columns less than the screen width (70 on 80 columns screens). An invalid parameter value or name causes an error message. -16- TVX Reference Manual 11/27/85 *** BACKUP LOG FILE FEATURE *** TVX has a backup log file feature. When the feature is enabled, all commands entered in any given session are saved on a file called "BACKUP.LOG" on the currently logged drive on CP/M and the current directory on MS-DOS and Unix systems. If for some reason you destroy your file during an editing session (like accidentally entering "100^K" instead of "100K"), you won't have to manually re-edit the backup version of the file. (By default, the log file is disabled.) The 'B' invocation time switch will respectively disable or enable the log file feature.) The "BACKUP.LOG" (the CP/M convention will be used in this description) file contains all the commands you entered in the last session. Most commands will appear in the log file as you entered them: R, U, D, etc. However, all control characters, backspace, and the atsign are encoded in the log file to make them appear as printable characters. The atsign '@' is used as an encoding character. So, for example, tabs appear as '@I', escapes as '@[', RETURNs as '@M', and so on. Control-A would appear as '@A'. The '@' itself would appear as '@@'. Backspace appears as '@H'. These escape sequences may be split across the end of a line in the log file. The end of line marks in the log file are not part of the command stream and are ignored. The procedure for using the "BACKUP.LOG" file to restore your file is as follows. When you realize you have made a mistake, enter the '^X' exit command. Copy "BACKUP.LOG" to a temporary working file. Now edit that temporary version of the log file to remove the mistakes, which should be near the end of the file. Once the log file has been edited to remove the bad commands, you should then re-edit the original file (the one without the mistakes). The latest version of the file will be the one with the mistakes, and should usually be killed. Start TVX and read in the file. Then enter the '@' command and supply the name of the "repaired" log file. All the commands in that log file will be applied to the original file. You should be careful to start the '@' command when the cursor is at a specific place such as the beginning of the file. After the '@' command is finished, your file will be in the same shape it was before the mistake. For example, suppose you are editing a file called "MYFILE0.TXT" and that you accidentally kill 100 lines. When you realize your mistake, you enter '^X' to exit. Then you should copy or rename the BACKUP.LOG file to a new temporary file - say FIX.LOG. The current version of the file you were editing is the bad file and should be deleted. On CP/M and MS-DOS versions, you would rename MYFILE0.BAK to be MYFILE0.TXT again. Then, edit FIX.LOG to remove the command that killed 100 lines and the quit command ("100@K@X"). Exit again, and re-edit MYFILE0.TXT. If you then enter the '@' command, and respond with FIX.LOG as the name of the command file, your file will be brought back to the state it was in right before the '100^K'. There are two cases that require special attention when using the backup log file. If you used a '^B' command during the session with -17- S