\chapter{TOPS-10 Operating Characteristics} \label{TOPS-10 Operating Characteristics} \section{Startup} TECO is started with the \begin{verbatim} .R TECO \end{verbatim command. TECO is now immediately ready to accept commands. The text buffer and Q-register areas are empty. Initial commands may also be specifified by following the monitor command with a dollar sign (\$) and then some TECO commands. For example, \begin{verbatim} .R TECO $3EH \end{verbatim} starts TECO with the help level flag set to 3. The TECO command \begin{verbatim} .TECO filespec \end{verbatim} is used to edit an already existing file. It is equivalent to \begin{verbatim} .R TECO *EBfilespec\escapeY\escape\escape \end{verbatim} TOPS-10 ``remembers'' the filespec as the name of the last file that has been edited. The MAKE command \begin{verbatim} .MAKE filespec \end{verbatim} is used to create a new file. It is equivalent to \begin{verbatim} .R TECO *EWfilespec\escape\escape \end{verbatim} TOPS-10 ``remembers'' the filespec as the name of the last file that was edited. The command \begin{verbatim} .MAKE filespec1=filespec2 \end{verbatim} is used to edit {\tt filespec2} into {\tt filespec1}. That is, {\tt filespec2} is opened as the input file, and {\tt filespec1} is created as the output file. It is equivalent to \begin{verbatim} .R TECO *ERfilespec2`EWfilespec1`Y`` \end{verbatim} TOPS-10 ``remembers'' the {\tt filespec1} as the name of the last file that was edited. The command \begin{verbatim} .TECO \end{verbatim} with no arguments, causes CCL to execute the command \begin{verbatim} .TECO filespec \end{verbatim} where filespec was the file that was previously remembered as the last file to be edited. The system purposely does not remember filenames from one editing session to the next, that is, when you log out, the system ``forgets'' the name of the file you were editing. TECO-10 does not require the use of the {\tt MUNG} command to execute TECO macros because runnable TECO programs can be created via use of the {\tt EE} command and these can then be run with the standard {\tt R} or {\tt RUN} command. This TECO command has the format \begin{verbatim} EEfilespec` \end{verbatim} which saves away the current image of TECO in the filename specified. The default extension is {\tt .EXE}. When the file is subsequently run (using the {\tt R} or {\tt RUN} monitor command), TECO resumes execution with the TECO command immediately following the {\tt EE} command. \section{Startup Conditions} \label{Startup Conditions} The initial value of the {\tt EU} flag is 0 if you are running on a terminal that does not support lower case, and is -1 if you are running on a terminal that does support lower case. The initial value of the {\tt ET} flag is as follows: \begin{tabular}{ll} Bit value & Initial value \\ 1 & 0 \\ 2 & 0 (1 if terminal is a scope) \\ 4 & 1 \\ 8 & 0 \\ 16 & 0 \\ 32 & 0 \\ 64 & 0 \\ 128 & 1 (TECO's prompt sets this to 0) \\ 256 & 0 \\ 512 & 0 (1 if VT support is present) \\ 1024 & 0 \\ 2048 & 0 \\ \end{tabular} The initial value of the ED flag is 1. \section{File Specification} The file access commands {\tt ER}, {\tt EB}, and {\tt EW} accept a file specification in the standard TOPS-10 format: \begin{verbatim} dev:filename.type[p,pn] \end{verbatim} in which {\tt dev:} is a physical device name or a user assigned logical name; if {\tt dev:} is not specified, the default {\tt DSK:} is assumed. The filename field must be specified in the commands {\tt ER}, {\tt EB}, and {\tt EW} and be a legal TOPS-10 filename. The type field is a file extension and must be explicitly given the first time. Thereafter, if a corresponding command is given with no extension specified, the system uses the previously specified extension as the default. The same defaulting rules hold for the dev: field. The {\tt } construct is permitted on any output filespecification to allow setting the protection of the file being created. \section{Backup Files} The {\tt EB} command maintains one level of file backup on TOPS-10. The pre-edited input file name is changed to \begin{verbatim} filename.BAK \end{verbatim} before the new output file is closed with the original name. Only normal file closing commands ({\tt EC}, {\tt EF}, {\tt EG}, and {\tt EX}) cause this renaming to happen. If TECO is aborted or the output file is purged by the {\tt EK} command, the input filename remains unchanged. Note only one {\tt .BAK} file for a given name is kept; earlier {\tt .BAK} backup files are deleted each time a new backup file is created. A good policy to follow when editing is to close the edited file frequently enough so that an unexpected incident would not cause a substantial loss of work. Files should be backed up regularly. TECO has the power to let an unsuspecting user alter a good file into a completely useless state. The {\tt FILCOM} program can be used to verify an editing session. \section{Exit And Go} If TECO is exited via the {\tt EG}\escape command, then TOPS-10 will re-execute the last explicit compile-class command that was executed during that session. \section{CTRL/C} The action taken when the user types {\tt } depends on what TECO is doing. At command level {\tt } is an immediate action command. If typed as the very first character in a command string (not necessarily the first keystroke) it aborts TECO and returns to the monitor. No Control-C trapping is available under TOPS-10. The {\tt ?XAB} error message is not supported. If {\tt } is typed in the middle of entering a command string, then TECO returns control to the monitor. Note that if TECO executes {\tt } as a command from command level, TECO is aborted. If TECO executes a {\tt } command from within a macro, TECO is also aborted. If two consecutive {\tt }s are typed while TECO is running, or while TECO is typing on the terminal, or while an error message is printing, then control returns to the operating system. If one {\tt } is typed to TECO while it is waiting for input, then control returns to the operating system. \section{Exceptions} TECO-10 does not support the following commands which are described in this manual: \begin{enumerate} \item Secondary streams ({\tt EP}, {\tt EA}, {\tt ER}\escape, {\tt EW}\escape) \item Wildcards ({\tt EN}) \item Immediate aids {\tt LF} and {\tt BS}. \end{enumerate} The following incompatibilities exist between TECO-10 and DEC's TOPS-10 TECO V24: \begin{enumerate} \item The {\tt nA} command under TOPS-10 TECO V24 always returned the value of the current character, regardless of the value of {\tt n}. In TECO-10, {\tt 0A} gives the value of the current character. \end{enumerate} \section{User Initialization} If a user has a file called {\tt TECO.INI} in his area, then when TECO starts up (via a CCL command), it will execute the contents of this file (as a TECO macro). This file must contain a valid TECO program. {\tt TECO.INI} will be executed before TECO opens any files. That is, if TECO was invoked via a {\tt MAKE} command, {\tt TECO.INI} will be executed before the {\tt EW} command (for the {\tt MAKE}) is executed. \section{Installation Instructions} To create TECO for TOPS-10 from the sources, issue the following commands: \begin{verbatim} .LOAD/MAC/COMPILE TECO10.T10+TECO10.MAC .SAVE TECO10 .LOAD/MAC/COMPILE TECERR.T10+TECO10.MAC .SAVE TECERR \end{verbatim} To create TECO for TOPS-20 from the sources, issue the following commands: \begin{verbatim} @LOAD/MAC/COMPILE TECO10 @SAVE TECO20 \end{verbatim} This builds a raw TECO. This version of TECO does not contain any window support since the {\tt W} and {\tt :W} commands are implemented as macros. To load window support, issue the following commands: \begin{verbatim} .RUN TECO10 (or TECO20) *EITECO10.TEC\escape\escape *EETECO\escape\escape \end{verbatim} You now have a runnable TECO image with window support. \section{TMPCOR Support} \label{TMPCOR Support} The {\tt EQ} and {\tt E\%} commands support the pseudo-device {\tt TMP:} for {\tt TMPCOR}. Onlhy the first three letters of the file name will be used, to try and access a {\tt TMPCOR} file. If that fails, it will try {\tt nnnNAM.TMP} where {\tt nnn} is your job number and {\tt NAM} is the three-character name. For example: for job 23, {\tt EQqTMP:FOOBAR}\escape will read {\tt TMPCOR} file {\tt FOO} or {\tt 023FOO.TMP}. \section{Q-register Names} \label{Q-register Names} Any printable character (except open parenthesis) is valid as a Q-register name. A Q-register whose name is a lower case alphabetic character is the same as the Q-register whose name consists of the corresponding upper case letter. Thus {\tt Qa} and {\tt QA} are equivalent commands. Q-register names may also be up to 6 characters long, by enclosing the name in parentheses, for example, {\tt Q(FOOBAR)}. Q-register names may contain any printable characters, however all characters other than letters, digits, dollar-sign, space, and underline are reserved for special use by TECO. A Q-register name consisting entirely of zero or more spaces is the same as Q-register {\tt ()}, which is special and discussed below. Trailing spaces in Q-register names are discarded, and lower case is converted to upper case. \section{Referencing The Text Buffer As A Q-register} \label{Referencing The Text Buffer As A Q-register} The Q-register with the null name: {\tt ()} is the text buffer. The numeric part of this Q-register is the value of {\tt dot}. The sequence {\tt [A ]()} causes Q-register A to share with the text buffer. The old main text buffer is lost (unless it is also sharing with some Q-register or if it has been saved on the Q-register push-down list). The text in Q-register A becomes the text buffer and the numeric part of Q-register A is used for {\tt .} if it is in range, otherwise {\tt dot} is set to 0. \section{Sharing Of Q-register Pointers} \label{Sharing Of Q-register Pointers} Q-registers may share their text with each other and with the text buffer as a result of {\tt [} and {\tt ]} commands. When a Q-register is pushed onto the Q-register pushdown list, all that is pushed is the numeric part of the Q-register and a pointer to the text part of the Q-register. Thus a command such as {\tt [A ]B} would cause Q-registers {\tt A} and {\tt B} to share the same text. The commands {\tt X}, \caret {\tt U}, and {\tt EQ} could be applied to either Q-register without modifying the other, since the Q-register is unbound from its previous text first. However, the colon-modified forms of {\tt X} and \caret {\tt U} append to the existing text, so a {\tt :X} or {\tt :}\caret{\tt U} command for either of them would affect the other. \section{Editing Line Sequence Numbered Files} \label{Editing Line Sequence Numbered Files} Some ASCII files have a special type of line number at the beginning of each line. These {\em line-sequence numbers} conform to certain rules so that they may be ignored or treated specially by compilers and other programs. The standards for line-sequence numbers are given in the {\em LINED Program Reference Manual}. TECO does not need line-sequence numbers for operation, but TECO can be used to edit files containing them. If such a file is edited with TECO-10, the line-sequence numbers are, in the normal case, simply preserved as additional text at the beginning of each line. The line-sequence numbers may be deleted, edited, and inserted exactly like any other text. On output, the line-sequence numbers are output according to the standard, except that the tab after the number is output only if it is already there. Leading zeros are added as necessary. If a line without a line-sequence number is encountered, a line-sequence number word of five spaces is placed at the beginning of the line. The following switches are available for use with line-sequence numebred files. These switches are merely added to the appropriate file selection command. \begin{verbatim} ERfilespec/SUPLSN` EBfilespec/SUPLSN` \end{verbatim} causes line sequence numbers to be suppressed at input time. The numbers will not be read into the editing buffer. Also, the tabs following the line-sequence numbers, if they exist, will be suppressed. \begin{verbatim} EWfilespec/SUPLSN` \end{verbatim} causes the line-sequence numbers to be suppressed at output time. Tabs following the line-sequence numbers will also be suppressed if they exist. \begin{verbatim} EWfilespec/GENLSN` EBfilespec/GENLSN` \end{verbatim} causes line sequence numbers to be generated for the output file if they did not already exist in the input file. Generated line-sequence numbers begin at 00010 and continue with increments of 10 for each line. Note that these switches are needed only if a change is to be made in the format of the file being edited. If no switches are specified, a file is output in the same form as it was input. \section{Compiler Restrictions} \label{Compiler Restrictions} TECO-10 is a compiler rather than an interpreter. This means, that before your command string is executed, TECO-10 compiles it into assembly language code. This makes it must faster than most other TECOs. Before executing a macro (with the {\tt Mq} command) TECO compiles the program in the macro. The next time the macro is executed, TECO notes that the macro has already been compiled and merely branches to the compiled code. If the contents of the Q-register are changed (via an {\tt X} or {\tt U} command), then TECO notes that it must re-compile the commands should the Q-register be invoked as a macro. One consequence of this is that if a syntax error is detected in a command, no portion of that command will have been executed. For example, typing the command {\tt HK=} will yield the {\tt ?NAE} error message and the text buffer will NOT be cleared. Another consequence of this is that you must not invoke a macro two different times using two different numbers of arguments. If a macro gets initially invoked with two arguments, then all subsequent invocations must supply two arguments. Also, TECO cannot tell while compiling an {\tt Mq} command whether or not the macro returns a value. Therefore it assumes that a value is always returned. This value can be explicitly removed by followed the {\tt Mq} command with an {\tt }. The {\tt MqA} command will compile the {\tt A} command as if it were an {\tt nA} command rather than an {\tt APPEND}.