Ian & Stuart's Australian Mac 1

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Text File | 1994-09-20 | 20KB | 637 lines

LOG captures MacDOS commands and their output. Syntax log [[file] [/A] [/O] | [/-]] Parameters file is the file to be used for storing captured information. It can include a volume and path spec. If file is missing, LOG closes the current logging file and stops logging. Switches /A appends logging data to the requested file instead of overwriting it. /O captures the output of commands. When /O is missing, only the commands themselves are captured. /- suppresses the storing of the closing message when closing a log file. You can then use a log file as a batch program without having to remove the closing message by hand. It only makes sense if the log file was opened WITHOUT the /O option. MacDOS vs DOS DOS does not support LOG. Notes File creator By default, LOG generates a file with creator 'ttxt' (for TeachText), but you can change it by SETting the system variable CREATOR. Frequently occurring errors E77: File already open for writing The file was already open in exclusive mode. Perhaps you were already using the same file for LOGging. MD, MKDIR create a folder (ie. MaKe a DIRectory). Syntax md name mkdir name The two commands are functionally identical. Parameters name is the name of the folder to be created. It can include a volume and path spec. MacDOS vs DOS The two implementations are identical. Examples Create a folder in the root directory: mkdir \foldName Create a subfolder of the current folder: mkdir subFold Create a folder in the same folder which contains the current one: mkdir ..\sisterFold Create a folder in the current folder of volume D: mkdir D:newFold Frequently occurring errors E58: Duplicate filename(s) There is already a folder or a file with the same name in the same place. Remember that names are NOT case sensitive. See Also RD, RMDIR, CD, CHDIR MEM provides information on the list of executing processes. Syntax mem MacDOS vs DOS MacDOS provides information similar to what is provided in DOS by the command MEM /PROGRAM . There are two main differences: • MacDOS does not provide information on system globals. • MacDOS provides additional information like the creator string and the path of the application file. MORE displays the content of a text file one page (ie. one window-full) at a time. Syntax more < file chain | more Parameters file is the name of a text file, possibly preceded by a volume and path spec. When file is missing, MORE accepts input from the keyboard. Input can then be terminated by typing a cntl-Z (that the Macintosh interprets as an EOF), a cntl-C, or a cmd-dot. chain is a chain of piped MacDOS filters, possibly including parameters and switches and beginning with a command. In its simplest form, a chain simply consists of a MacDOS command that accepts output redirection. MacDOS vs DOS MacDOS does not prompt the user at the end of each page when the output is redirected to a disk file. DOS only allow MORE to be preceded by a single command. Notes Generating text files You can generate small text files by executing MORE without parameters by redirecting its output to a disk file: more > newFile MORE then keeps storing what you type into newFile until you type a cntl-Z. If your keyboard does not have the CNTL key, you can type cmd-dot instead. Nevertheless, as a cmd- dot aborts the current line, you should only type it after the last RETURN. This method of producing text files is only practical for batch programs of a couple of lines or small files for test purposes. Examples more < \documents\myTextFile myFilter < filterInput | more dir | more help xcopy | more dir/b/a-d | filter1 | filter2 | more Frequently occurring errors E40: Not a file of type 'TEXT' MORE can only display text files. See Also TYPE NEXT terminates a multi-line FOR-loop. Syntax next varname Parameters varname is the control variable of the FOR-loop. MacDOS vs DOS DOS does not support NEXT. Notes Jumping in and out of FORs If you jump into a FOR-loop with a GOTO, MacDOS does not automatically report an error. This is partly due to the fact that MacDOS ignores the NEXT command if the control variable does not exist. You should always enter loops from the top. If a FOR-loop is exited with a GOTO before it is completed, MacDOS "remembers" that the loop was not completed and does not release the control variable. Therefore, it is possible to jump out, do something, and jump back in. If you jump out of a FOR-loop and then try to restart it from the beginning, MacDOS reports the error message: Variables used in iterations must be unique because the control variable was not released. See Also FOR ONERROR specifies a label for error handling in batch. Syntax onerror [label] Parameters label is a label from which batch execution continues whenever MacDOS encounters an error. When this parameter is missing, ONERROR resets the error handling. MacDOS vs DOS DOS does not support ONERROR. Notes Standard handling After detecting an error, MacDOS aborts the current command and continues execution of the batch program from the following line. Error routine You can implement an error routine by setting a variable with a return label: onerror ERR_LBL set return_lbl=RET_LBL if this line causes an error we resume execution from ERR_LBL :RET_LBL here is where we come back from the error routine ... :ERR_LBL here we handle the error before resuming normal execution goto %return_lbl% Examples onerror onerror ERR_LBL onerror %var% See Also SHOW OPEN opens a text file for sequential access. Syntax open [file [var]] [{/R | /W | /A}] Parameters file is the name of a file of type 'TEXT', possibly preceded by a volume and path spec. When file is missing, OPEN displays the list of files already open. After being OPENed, the file can be accessed with the commands READ or WRITE and closed with CLOSE. var is the name of the variable into which the fileID is to be stored. When var is missing, OPEN displays the fileID in the MacDOS window. Switches Only one of /R, /W, and /A at a time is allowed in a command. When no switch is provided, /R is assumed. /R opens an existing text file to read (see the command READ). If the file does not exist, OPEN fails. /W opens a new text file to write (see the command WRITE). If the file already exists, OPEN replaces it with the new one. /A opens an existing text file to write past the current EOF (see the command WRITE). If the file does not exist, OPEN creates it. MacDOS vs DOS DOS does not support OPEN. Notes Forks OPEN only sees the data fork of text files. Non-text files You can READ the data fork of a file not of type 'TEXT' by copying it: COPY/D filename theCopy and changing its type: REN theCopy /t!TEXT (at this point, you can also use TYPE and MORE to display it). Concurrent access The same file can be opened more than once for reading but only once for writing. This also applies to files opened directly by MacDOS (eg. to read a batch program or for I/O redirection) or by other applications (compilers, word processors, etc.). You should not change the content of a file while it is being read. When you OPEN a file, MacDOS keeps in memory the current file offset and has no way of checking whether it remains valid. Therefore, it is of particular importance that the length of the portion already READ remains unchanged. File reset If you OPEN a file for writing and CLOSE it immediately thereafter, this will have the effect of removing its content, while leaving its creator unchanged. Examples open myFile open 2:\aFold\aFile aVar /R open memoList saveID /a open Frequently occurring errors E27: File or directory not found When OPENing for reading, the parameter did not identify any file at all. Alternatively, one of the directories specified in the path could not be found. E34: Illegal wildcarding You were trying to open a folder instead of a file: MacDOS tried to open all the files contained in the folder and then failed because OPEN can only open a file at a time. E40: Not a file of type 'TEXT' You can only OPEN text files. Perhaps you forgot to save it from your word processor as "text only". E77: File already open for writing The file to be OPENed for writing was already open in exclusive mode, either by MacDOS or by another application. Check what files you have opened in your word processor and/or editor. Some applications fail to close a file when you close the corresponding window (yes, it is a bug!). In those cases, you will have to quit the application in order to free the file. See Also READ, WRITE, CLOSE PATH displays and sets search paths for executable files. Syntax path [paths] "PATH paths" is equivalent to "SET PATH=paths" Parameters paths is a list of paths separated by semicolons. If paths is missing, PATH displays the current list. If paths consists of a single semicolon, PATH resets the list. MacDOS vs DOS The two implementations are identical. Notes Global variable PATH MacDOS stores the list of paths in a global system variable named PATH. Therefore, the command path listOfPaths is completely equivalent to set path=listOfPaths Similarly, path ; is equivalent to set path= Changing the current PATH You can easily append a new folder to the current PATH by typing any of the following three commands: path %path%;newFolder set path=%path%;newFolder incr path by ;newFolder Similarly, to insert a new folder at the beginning of the current PATH, you can type: path newFolder;%path% set path=newFolder;%path% incr -path by newFolder; Also look at the batch programs addPath.bat and delPath.bat in the batches folder of the MacDOS floppy. Order of searching and multiple filenames MacDOS looks for executable files in the current folder (first without extension, then after appending the extensions .BAT) before scanning the folders identified in the global variable PATH. When looking for an executable file or a file of abbreviations, MacDOS scans the paths from left to right until it finds a file with the correct name. Therefore, when several files with the same name are in the different folders of the path, MacDOS only sees the first one. Examples path ; path path "c:\;\bin;1:\application folder;1:\batches" PAUSE suspends execution of a batch program and asks whether execution should be resumed. Syntax pause MacDOS vs DOS The two implementations are identical. Notes PAUSE vs cntl-C PAUSE lets you interrupt a batch program in a controlled way, while a cntl-C (or cmd-dot) interrupts batch execution asynchronously. After being PAUSEd, a batch program can always continue without problems. On the other hand, cntl-C is risky, because it actually interrupts individual commands. When you resume execution after a cntl-C, MacDOS does NOT complete the command which was interrupted, but simply continues with the next line of the batch program. PRINT prints a text file. Syntax print [file] [/P] [/D] Parameters file specifies what is to be printed. It can be a filename, a wildcarded filename, or a folder name, possibly preceded by a volume and path spec. If file is omitted, PRINT prints the text contained in the console window. Switches /P prompts you for confirmation before printing each file. /D displays the standard Print dialog before printing the file. When printing a wildcarded series of files, the dialog is only displayed before printing the first file of the series. The parameter settings are then applied to all following prints until you execute PRINT/D once more. MacDOS vs DOS Options and parameters MacDOS supports none of the DOS options, but it can prompt you with the switch /P and /D. Only one parameter is accepted by MacDOS, but it can be wildcarded or specify a folder. Notes Page Setup and Print console menu items The "Page Setup..." item in the "File" menu behaves in the usual way. The "Print console..." item prints what is in the MacDOS window. Print dialog box By default, the command PRINT does not put up the usual Macintosh dialog box. Thefeore, it lets you print several text files without having to click the mouse for each one of them. It normally prints one copy of each entire file but you can change the default via the "Print console..." item of the "File" menu or the switch /D. MacDOS will then apply the same settings when executing PRINT until you change them again. Form Feeds When MacDOS encounters a line which begins with a FF character (cntl-L = 0x0C), it executes a form feed without printing that line. Examples print "\myProject folder\sources\*.c" print \mixedFiles /p print "a file" /D Frequently occurring errors E27: File or directory not found The parameter did not identify any file at all or one of the directories specified in the path could not be found. E40: Not a file of type 'TEXT' You can only PRINT text files. Perhaps you forgot to save it from your word processor as "text only". PROMPT changes the command prompt. Syntax prompt [text] "PROMPT text" is equivalent to "SET PROMPT=text" Parameters text specifies what you want to have in the command prompt. When PROMPT encounters in text a dollar sign, it interprets the following character as a request to insert special strings into the command prompt. The possible requests are: $B | (pipe) $D current date $E escape (ASCII code 27) $G > (greater-than sign) $H backspace (erases the previous character) $L < (less-than sign) $N current volume $P current volume and path $Q = (equal sign) $T system time $V MacDOS version number $_ new-line $$ $ (dollar sign) When text is missing, PROMPT resets the command prompt to the default string ($N$G). MacDOS vs DOS The two implementations are identical. Notes Date and Time formats The date and time formats are set with DATE and TIME respectively. Paths and dismounted volumes If you EJECT a floppy while you are attached to it and your command prompt contains $P, you will get the error message "No such volume" after every prompt. To avoid such an error message you should attach to a mounted volume. Naturally, you could also remove the $P from the prompt string. Examples command prompt prompt $p$g C:\MacDOS folder> prompt "Now: $t$$" Now: 13:33:16$ prompt $d;$t$_$v ! 94-09-30;13:35:10 2.0.0 ! See Also DATE, TIME, VER, VOL, CD RD, RMDIR delete an empty folder (ie. ReMove a DIRectory). Syntax rd name rmdir name The two commands are functionally identical. Parameters name is the name of the folder to be removed. It can include a volume and path spec. MacDOS vs DOS The two implementations are identical. Notes RMDIR vs. DEL DEL followed by a folder name deletes all the files in the folder, while RMDIR followed by the same folder name actually removes the folder (if it is empty). Examples Removes a folder from the root directory: rmdir \foldName Removes a subfolder of the current folder: rmdir subFold Removes a folder from the same folder which contains the current one: rmdir ..\sisterFold Removes a folder from the current folder of volume D: rmdir D:oldFold Removes a folder from the root directory of volume D: rmdir D:\aFold Frequently occurring errors E49: File busy, dir non empty, or path error RMDIR can only remove a folder if it is empty. See Also MD, MKDIR, CD, CHDIR READ reads a line of text from a file opened with OPEN. Syntax read fileID [var] Parameters fileID is the number returned by OPEN. The file can be closed with the command CLOSE, but MacDOS closes it automatically when it encounters the EOF. var is the name of the global variable into which the read line is to be stored. If var is omitted, MacDOS displays the line in the MacDOS window. MacDOS vs DOS DOS does not support READ. Notes Line termination READ strips the newline character (CR) at the end of each line containing more than one character. If the CR is the only character in the line, MacDOS replaces it with a space. This guarantees that the line returned is never empty. Examples read 3 reads a line from file #3 and displays it on the monitor's screen. read %fileID% aLine reads a line from the file whose ID is stored in the variable fileID and stores it into the variable aLine. read %2 reads a line from the file whose ID was passed to the batch program via the second replaceable parameter. Frequently occurring errors E3: File not opened by the user The file you wanted to READ was not opened. Remember that MacDOS automatically closes the file when you reach the EOF. See Also OPEN, WRITE, CLOSE