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6 Working with Files This section describes the MacDOS commands which let you work with files. Many MacDOS commands operate on files. To tell MacDOS where to look for them, you specify the folder which contains them. If you do not specify any folder, MacDOS looks for the files in the current folder. Identifying a File Like with folders, you identify a file through its name and its location. Therefore, to identify a file you must provide: • The ID of the volume which contains the file. • The name of all folders, one inside the other, which you need to open in order to "reach" from the root the file you are looking for. • The name of the file. To fully identify a file in MacDOS you need to type something like this: 1:\fold1\aDeeperFold\still deeper\myFile and all the considerations made in the previous section concerning folders apply to files. File names are strings of up to 31 characters in length. They are not allowed to contain colons, and you should also avoid other special characters, as they can create problems and confusion. For example, if you include a slash in a filename and then forget to double quote the name when you use it in a command, MacDOS will interpret the part beginning with the slash as a switch. Moreover, most MacDOS commands reject as bad switches names beginning with a slash, whether you double quote them or not. For similar reasons, you should also avoid backslashes. Also note that if you include a comma in a filename, you will have problems in copying it, because the command COPY accepts comma-separated filenames. In general, try to avoid characters which are used as separators. Creating New Files There are three ways of creating a new file with MacDOS: • Create a file with the command OPEN and then write into it lines of text with the command WRITE (please refer to one of the following sections for the details). • Use the command LOG to record all the commands executed by MacDOS (please refer to the "Getting Info" section of this User's Guide). • Redirect the output of a MacDOS command to a disk file (please refer to "The Environment" section of this User's Guide). By default, the files created are of type 'TEXT' and creator 'ttxt' (ie. TeachText), but you can change the creator by updating the system variable CREATOR. Removing Files You can remove files with the commands DEL and ERASE. The two commands have different names but are identical for what concerns functionality. Therefore, what is said about DEL always applies 100% to ERASE. DEL accepts a single parameter which specifies the file you want to delete or the folder you want to empty of files. If you include wildcard characters in the parameter, DEL deletes all the files whose names match the parameter. You also have the possibility of selecting files on the basis of their creator, type, or both. To delete all the files in a particular folder, you can pass to DEL a "catch all" filename or simply the name of the folder: del D:\theFolder\* del D:\theFolder In either case, MacDOS prompts you for confirmation. Note that DEL permanently removes the files from the system rather than simply moving them to the Trash. To limit the danger of such a drastic behaviour, MacDOS prompts you for confirmation before deleting each individual file. Nevertheless, you can switch this safeguard off by executing the command CONFIRM OFF . To re-enable the prompting for a single DEL command, add the switch /P. To re-enable it permanently, execute the command CONFIRM ON . Listing Files You can list files with two commands: MORE and TYPE. MORE displays the content of the data fork of files of type 'TEXT' one page at a time. At the end of each page, MORE waits for you to type any character before continuing. You can also interrupt the listing by pressing cmd-dot (or cntl- C). MORE is a special command, in that it expects that you specify a file as input redirection rather than as a parameter. So, if you want to list the file 2:\aFold\theFile, you must type: more <2:\aFold\theFile rather than simply: more 2:\aFold\theFile TYPE, when used in its basic form, also lists the data fork of files of type 'TEXT' on the monitor screen. The differences are that TYPE expects a file specification as a parameter and only stops when it reaches the End Of File (EOF). You can pause and resume long listings with cntl-S and cntl-Q respectively. To list the data or resource fork of any file (not only text files), use TYPE with the switches /H and /R respectively. TYPE then lists the requested fork in HEX, as well as in ASCII, 16 bytes per line. Copying Files To copy files, you can use the commands COPY and XCOPY. This section only describes COPY. Please refer to the section "Working with Folders" for a description of XCOPY. In its simplest form, COPY makes a duplicate of a file which already exists and places it in the current folder: copy aFileSpec . The difference with the "Duplicate" menu item provided by the Finder is that COPY's duplicate has the same name as the original file. Therefore, if you COPY a file which already is in the current folder, your command does not have any visible effect and you do not get any duplicate at all. If you pass to COPY a second file specification, you can: • specify a different name for the duplicate; • place the duplicate anywhere in the system rather than in the current folder. The two file specifications are usually called "source" and "destination". With this format, you can reproduce the Finder's Duplicate function as follows: copy fileName "fileName copy" A duplicate of the file fileName in the current folder (ie. the front window) is created and named fileName copy. Note that the double quotes are only necessary because the new name contains a space. If you use the destination to specify a folder rather than a file, the duplicate file is created with the same name as the original. In other words, the two following commands are equivalent: copy fileName destFolder\fileName copy fileName destFolder Still using the second parameter to specify a folder, you have three ways of COPYing several files at a time: • By replacing the single source with a series of file specifications separated by commata, you COPY all the individual source files to the destination folder: copy file1,aFold\file2,2:file3 destFolder • By wildcarding the source, you COPY all the files with matching filenames to the destination folder: copy sourceFolder\p*a??? destFolder • By using the first parameter to specify a folder rather than a file, you COPY all the files in the source folder to the destination folder: copy sourceFolder destFolder If you specify more than one file as a source parameter but use the second parameter to specify a single file, COPY merges all the sources to produce the destination. This can be useful to append to each other several data or text files. COPY supports several options: • Append the source to an existing destination. • Only copy files of a given Creator or Type. • Only copy the Data or Resource fork of files. • Display a Prompt before overwriting destination files. • Only copy files which either do not exist in the destination folder or do exist but have an older Update date and time. • Verify that the copies are correct. Renaming Files To rename files, you can use the commands REN and RENAME. Apart from their name, the two commands are identical. In its simplest format, REN works as follows: ren fileSpec newName The first parameter specifies the file to be renamed and the second parameter tells MacDOS what the new name should be. If the first parameter ends with a wildcarded filename, all the files with matching names are renamed. In that case, the second parameter is used to replace in each name the part which precedes the first wildcard character. For example: ren abc* xyz renames abc to xyz, abcf to xyzf, "abc whatever" to "xyz whatever", etc. In this form, REN can also be used to insert a string before all filenames: ren * prependThis MacDOS also accepts wildcards in the second parameter. In that case, MacDOS matches the groups of wildcards and replaces the corresponding parts. If the first parameter specifies a folder rather than a file, MacDOS renames all the files in the folder. Therefore, the two following commands have identical results: ren aFold\* x*z ren aFold x*z In both cases, MacDOS prepends an 'x' and appends a 'z' to the name of each file in the folder aFold. Through a series of options, REN also lets you select files on the basis of their creator and type. You can also specify whether the name selection should be case sensitive or not. Changing File Attributes You can use the command REN and (RENAME, which is identical) to change more than just the names of files. In particular, you can: • set new creators; • set new file-types; • set the date and time of the last update to the current date and time; • hide a visible file and viceversa. This functionality is controlled through switches. For example, "ren zz /h" hides the file named zz, and "ren/c!????" changes the creator of all files in the current folder to '????' (be careful!). Printing Text Files You can print files of type 'TEXT' with the command PRINT. The format of PRINT is: print fileSpec . The file specification can be wildcarded or can be replaced with a folder specification, in which case all text files in the folder are printed. Without parameter, PRINT prints what is displayed in the console window. Before PRINTing, you can specify the page format with the standard "Page Setup ..." item of the File menu. Instead of displaying the standard Print dialog every time you print, MacDOS prints with a default selection, so that you can PRINT several files without having to click for each one of them. With the /D switch you can direct MacDOS to display the standard "Print..." dialog before printing the first file. Direct File I/O MacDOS lets you OPEN, READ or WRITE, and CLOSE files of type 'TEXT'. You can OPEN a file for reading, writing, or appending. In each case, one line of text at a time is transferred in each I/O operation, either from disk to memory or from memory to disk. When READing, you can store the line into a global variable for later processing, or display it for immediate view. After you have READ from a file the last line, MacDOS automatically closes it. By default, MacDOS creates new files with creator 'ttxt' (ie. TeachText), but you can change it by setting the system variable CREATOR to your preferred creator. Type OPEN without parameters to display the list of files which are currently open.