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diff --git a/contrib/nvi/docs/USD.doc/edit/edittut.ms b/contrib/nvi/docs/USD.doc/edit/edittut.ms deleted file mode 100644 index 8a9d66ede2e6..000000000000 --- a/contrib/nvi/docs/USD.doc/edit/edittut.ms +++ /dev/null @@ -1,2280 +0,0 @@ -.\" Copyright (c) 1980, 1993 -.\" The Regents of the University of California. All rights reserved. -.\" -.\" Redistribution and use in source and binary forms, with or without -.\" modification, are permitted provided that the following conditions -.\" are met: -.\" 1. Redistributions of source code must retain the above copyright -.\" notice, this list of conditions and the following disclaimer. -.\" 2. Redistributions in binary form must reproduce the above copyright -.\" notice, this list of conditions and the following disclaimer in the -.\" documentation and/or other materials provided with the distribution. -.\" 3. All advertising materials mentioning features or use of this software -.\" must display the following acknowledgement: -.\" This product includes software developed by the University of -.\" California, Berkeley and its contributors. -.\" 4. Neither the name of the University nor the names of its contributors -.\" may be used to endorse or promote products derived from this software -.\" without specific prior written permission. -.\" -.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND -.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE -.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE -.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE -.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL -.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS -.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) -.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT -.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY -.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF -.\" SUCH DAMAGE. -.\" -.\" @(#)edittut.ms 8.3 (Berkeley) 8/18/96 -.\" -.ll 6.5i -.nr LL 6.5i -.EH 'USD:11-%''Edit: A Tutorial' -.OH 'Edit: A Tutorial''USD:11-%' -.LP -.ds u \s-2UNIX\s0 -.ND -.sp 4 -.ce -\f3\s+2Edit: A Tutorial\s0\f1 -.sp -.ce 3 -.I -Ricki Blau -.sp -James Joyce -.R -.sp -.ce 3 -Computing Services -University of California -Berkeley, California 94720 -.sp 3 -.ce -.I -ABSTRACT -.R -.sp -.LP -This narrative introduction to the use of the text editor -.I edit -assumes no prior familiarity with computers or with text editing. -Its aim is to lead the beginning \s-2UNIX\(dg\s+2 user through the -.FS -\(dgUNIX is a trademark of Bell Laboratories. -.FE -fundamental steps of writing and revising a file of text. -Edit, -a version of the text editor -.I ex, -was designed to provide an informative environment -for new and casual users. -.PP -We welcome comments and suggestions about this tutorial -and the \s-2UNIX\s+2 documentation in general. -.sp .5v -September 1981 -.bp -.ll 6.5i -.nr LL 6.5i -.nr LT 6.5i -.ds u \s-2UNIX\s0 -.ce -\s+2\f3Contents\f1\s0 -.LP -.nf -Introduction\ \ \ 3 -.sp -Session 1\ \ 4 -.in +.5i -Making contact with \s-2UNIX\s+2\ \ \ 4 -Logging in\ \ 4 -Asking for \fIedit\fR\ \ \ 4 -The ``Command not found'' message\ \ \ 5 -A summary\ \ 5 -Entering text\ \ \ 5 -Messages from \fIedit\fR\ \ \ 5 -Text input mode\ \ \ 6 -Making corrections\ \ \ 6 -Writing text to disk\ \ \ 7 -Signing off\ \ 7 -.in -.5i -.sp -Session 2\ \ \ 8 -.in +.5i -Adding more text to the file\ \ \ 8 -Interrupt\ \ \ 8 -Making corrections\ \ \ 8 -Listing what's in the buffer (p)\ \ \ 9 -Finding things in the buffer\ \ \ 9 -The current line\ \ \ 10 -Numbering lines (nu)\ \ \ 10 -Substitute command (s)\ \ \ 10 -Another way to list what's in the buffer (z)\ \ \ 11 -Saving the modified text\ \ \ 12 -.in -.5i -.sp -Session 3\ \ \ 13 -.in +.5i -Bringing text into the buffer (e)\ \ \ 13 -Moving text in the buffer (m)\ \ \ 13 -Copying lines (copy)\ \ \ 14 -Deleting lines (d)\ \ \ 14 -A word or two of caution\ \ \ 15 -Undo (u) to the rescue\ \ \ 15 -More about the dot (.) and buffer end ($)\ \ \ 16 -Moving around in the buffer (+ and \-)\ \ \ 16 -Changing lines (c)\ \ \ 17 -.in -.5i -.sp -Session 4\ \ \ 18 -.in +.5i -Making commands global (g)\ \ \ 18 -More about searching and substituting\ \ \ 19 -Special characters\ \ \ 19 -Issuing \s-2UNIX\s+2 commands from the editor\ \ \ 20 -Filenames and file manipulation\ \ \ 20 -The file (f) command\ \ \ 20 -Reading additional files (r)\ \ \ 21 -Writing parts of the buffer\ \ \ 21 -Recovering files\ \ \ 21 -Other recovery techniques\ \ \ 21 -Further reading and other information\ \ \ 22 -Using \fIex\fR\ \ \ 22 -.in -.5i -.sp -Index\ \ \ 23 -.bp -.SH -.ce -\s+2Introduction\s0 -.PP -Text editing using a terminal connected to a computer -allows you to create, modify, and print text -easily. -A -.I -text editor -.R -is a program -that assists you -as you create and modify text. -The text editor you will learn here is named -.I edit. -Creating text using edit is as easy as typing it -on an electric typewriter. -Modifying text involves telling the text editor -what you want to add, change, or delete. -You can review your text -by typing a command -to print the file contents -as they are currently. -Another program (which we do not discuss in this -document), a text formatter, -rearranges your text -for you into ``finished form.'' -.PP -These lessons assume no prior familiarity with computers -or with text editing. -They consist of a series of text editing sessions -which lead you through the fundamental steps -of creating and revising text. -After scanning each lesson and before beginning the next, -you should try the examples at a terminal to get a feeling -for the actual process of text editing. -If you set aside some time for experimentation, -you will soon become familiar with using the -computer to write and modify text. -In addition to the actual use of the text editor, -other features of \s-2UNIX\s0 will be very important to your work. -You can begin to -learn about these other features by -reading one of the other tutorials -that provide a general introduction to the system. -You will be ready to proceed with this lesson as soon as -you are familiar with (1) your terminal and its special keys, -(2) how to login, -(3) and the ways of correcting typing errors. -Let's first define some terms: -.sp .5 -.IP program 12 -A set of instructions, given to the computer, -describing the sequence of steps the computer performs -in order to accomplish a specific task. -The task must be specific, -such as balancing your checkbook -or editing your text. -A general task, -such as working for world peace, -is something we can all do, -but not something we can currently write programs to do. -.IP UNIX -\s-2UNIX\s0 is a special type of program, -called an operating system, that supervises the machinery -and all other programs comprising the total -computer system. -.IP edit -.I edit -is the name of the \s-2UNIX\s0 text editor you will be learning to use, -and is a program that aids you in writing or revising text. -Edit was designed for beginning users, -and is a simplified version of an editor named -.I ex. -.IP file -Each \s-2UNIX\s0 account is allotted -space for the permanent storage of information, -such as programs, data or text. -A file is a logical unit of data, -for example, an essay, a program, -or a chapter from a book, -which is stored on a computer system. -Once you create a file, -it is kept until you instruct the system to remove it. -You may create a file during one \s-2UNIX\s0 session, -end the session, -and return to use it at a later time. -Files contain anything you choose to write and store in them. -The sizes of files vary to suit your needs; -one file might hold only a single number, -yet another might contain -a very long document or program. -The only way to save -information from one session to the next is to store it in a file, -which you will learn in Session 1. -.IP filename -Filenames are used to distinguish one file from another, -serving the same purpose as the labels of manila -folders in a file cabinet. -In order to write or access information in a file, -you use the name of that file in a \s-2UNIX\s0 command, -and the system will automatically locate the file. -.IP disk -Files are stored on an input/output device called a disk, -which looks something like a stack of phonograph records. -Each surface is coated with a material similar to that -on magnetic recording tape, -and information is recorded on it. -.IP buffer -A temporary work space, made available to the user -for the duration of a session of text editing -and used for creating and modifying -the text file. -We can think of the buffer as a blackboard that is -erased after each class, where each session with the editor -is a class. -.bp -.SH -.ce 1 -\s+2Session 1\s0 -.sp 1 -.SH -Making contact with \s-1UNIX\s0 -.PP -To use the editor you must first make contact with the computer -by logging in to \s-2UNIX\s0. -We'll quickly review the standard \s-2UNIX\s0 login procedure -for the two ways you can make contact: -on a terminal that is directly linked to the computer, -or over a telephone line where the computer answers your call. -.SH -Directly-linked terminals -.PP -Turn on your terminal and press the \s-1RETURN\s0 key. -You are now ready to login. -.SH -Dial-up terminals -.PP -If your terminal connects with the computer over a telephone line, -turn on the terminal, dial the system access number, -and, when you hear a high-pitched tone, place the -telephone handset in the acoustic coupler, if you are using one. -You are now ready to login. -.SH -Logging in -.PP -The message inviting you to login is: -.DS I 1i -login: -.DE -.LP -Type your login name, which identifies you to \s-2UNIX\s0, -on the same line as the login message, -and press \s-2RETURN\s+2. -If the terminal you are using -has both upper and lower case, -.B -be sure you enter your login name in lower case; -.R -otherwise \s-2UNIX\s0 assumes your terminal -has only upper case and will not recognize lower case -letters you may type. -\s-2UNIX\s0 types ``login:'' and you reply -with your login name, for example ``susan'': -.DS I 1i -login: \fBsusan\fR \fI(and press the \s-2RETURN\s0 key)\fR -.DE -(In the examples, input you would type appears in -.B "bold face" -to distinguish it from the responses from \s-2UNIX\s0.) -.PP -\s-2UNIX\s0 will next respond with a request for a password -as an additional precaution to prevent -unauthorized people from using your account. -The password will not appear when you type it, -to prevent others from seeing it. -The message is: -.DS I 1i -Password: \fI(type your password and press \s-2RETURN\s+2)\fR -.DE -If any of the information you gave during the login -sequence was mistyped or incorrect, -\s-2UNIX\s0 will respond with -.DS I 1i -Login incorrect. -.if t .sp .2v -.if n .sp 1 -login: -.DE -in which case you should start the login process anew. -Assuming that you have successfully -logged in, \s-2UNIX\s0 -will print the message of the day and eventually will present -you with a % at the beginning of a fresh line. -The % is the \s-2UNIX\s0 prompt symbol -which tells you that \s-2UNIX\s0 is ready to accept a command. -.bd I 3 -.SH -Asking for \fIedit\fP -.fl -.bd I -.PP -You are ready to tell \s-2UNIX\s0 that you -want to work with edit, the text editor. -Now is a convenient time to choose -a name for the file of text you are about to create. -To begin your editing session, -type -.B edit -followed by a space and then the filename -you have selected; for example, ``text''. -After that, -press the \s-2RETURN\s0 key and wait for edit's response: -.DS I 1i -% \fBedit text\fP \fI(followed by a \s-2RETURN\s+2)\fR -"text" No such file or directory -: -.DE -If you typed the command correctly, -you will now be in communication with edit. -Edit has set aside a buffer for use as -a temporary working space during your current editing session. -Since ``text'' is a new file we are about to create -the editor was unable to find that file, which it -confirms by saying: -.DS I 1i -"text" No such file or directory -.DE -On the next line appears edit's prompt ``:'', -announcing that you are in \f2command mode\f1 and -edit expects a command from you. -You may now begin to create the new file. -.SH -The ``Command not found'' message -.PP -If you misspelled edit by typing, say, ``editor'', -this might appear: -.DS I 1i -% \fBeditor\fP -editor: Command not found -% -.DE -Your mistake in calling edit ``editor'' was -treated by \s-2UNIX\s0 as a request -for a program named ``editor''. -Since there is no program -named ``editor'', -\s-2UNIX\s0 reported that the program was ``not found''. -A new % indicates that \s-2UNIX\s0 is ready for another command, -and you may then enter the correct command. -.SH -A summary -.PP -Your exchange with \s-2UNIX\s0 as you logged in and made contact with edit -should look something like this: -.DS I 1i -login: \fBsusan\fP -Password: -\&... A Message of General Interest ... -% \fBedit text\fP -"text" No such file or directory -: -.DE -.SH -Entering text -.PP -You may now begin entering text into the buffer. -This is done by \fIappending\fP (or adding) text to whatever -is currently in the buffer. -Since there is nothing in the buffer at the moment, -you are appending text to nothing; -in effect, -since you are adding text to nothing -you are creating text. -Most edit commands have two equivalent forms: -a word that suggests what the command does, -and a shorter abbreviation of that word. -Many beginners find the full command names -easier to remember at first, -but once you are familiar with editing you may -prefer to type the shorter abbreviations. -The command to input text is ``append''. -(It may be abbreviated ``a''.) -Type -.B append -and press the \s-2RETURN\s0 key. -.DS I 1i -% \fBedit text -\fR:\|\fBappend -.R -.DE -.SH -.bd I 3 -Messages from -.I edit -.fl -.bd I -.PP -If you make a mistake in entering a command and -type something that edit does not recognize, -edit will respond with a message -intended to help you diagnose your error. -For example, if you misspell the command to input text by typing, -perhaps, ``add'' instead of ``append'' or ``a'', -you will receive this message: -.DS I 1i -:\|\fBadd\fR -add: Not an editor command -: -.DE -When you receive a diagnostic message, -check what you typed in order to determine what -part of your command confused edit. -The message above means that edit -was unable to recognize your mistyped command -and, therefore, did not execute it. -Instead, a new ``:'' -appeared to let you know that -edit is again ready to execute a command. -.SH -Text input mode -.PP -By giving the command ``append'' (or using the abbreviation ``a''), -you entered -.I -text input mode, -.R -also known as -.I -append mode. -.R -When you enter text input mode, -edit stops sending you a prompt. -You will not receive any prompts -or error messages -while in text input mode. -You can enter -pretty much anything you want on the lines. -The lines are transmitted one by one to the buffer -and held there during the editing session. -You may append as much text as you want, and -.I -when you wish to stop entering text lines you should -type a period as the only character on the line -and press the \s-2RETURN\s0 key. -.R -When you type the period and press \s-2RETURN\s0, -you signal that you want to stop appending text, -and edit responds by allowing -you to exit text input mode and reenter command mode. -Edit will again -prompt you for a command by printing ``:''. -.PP -Leaving append mode does not destroy the text in -the buffer. -You have to leave append -mode to do any of the other kinds of editing, -such as changing, adding, or printing text. -If you type a period as the first character and -type any other character on the same line, -edit will believe you want to remain in append mode -and will not let you out. -As this can be very frustrating, -be sure to type -.B only -the period and the \s-2RETURN\s0 key. -.PP -This is a good place to learn an important -lesson about computers and text: a blank space is -a character as far as a computer is concerned. -If you so much as type a period followed by a blank -(that is, type a period and then the space bar on the keyboard), -you will remain in append mode with the last line of text -being: -.DS I 1i -.B -.ps +2 -\&. -.ps -2 -.R -.DE -Let's say that you enter the lines -(try to type -.B exactly -what you see, including ``thiss''): -.DS I 1i -.B -This is some sample text. -And thiss is some more text. -Text editing is strange, but nice. -\&. -.R -.DE -The last line is the period followed by a \s-2RETURN\s0 -that gets you out of append mode. -.SH -Making corrections -.PP -If you have read a general introduction to \s-2UNIX\s0, -you will recall that it is possible to erase individual -letters that you have typed. -This is done by typing the designated erase character -as many times as there are characters -you want to erase. -.PP -The usual erase character varies from place to place and -user to user. Often it -is the backspace (control-H), -so you can correct typing errors -in the line you are typing -by holding down the \s-1CTRL\s+1 key -and typing the ``H'' key. (Sometimes it is the DEL key.) -If you type the erase character -you will notice -that the terminal backspaces in the line you are on. -You can backspace over your error, -and then type what you want to be the rest of the line. -.PP -If you make a bad start -in a line -and would like to begin again, -you can either backspace to the beginning of the line -or you can use the at-sign ``@'' to erase everything on the line: -.DS I 1i -.B -Text edtiing is strange, but@ -Text editing is strange, but nice. -.R -.fl -.bd S -.DE -When you type the at-sign (@), you erase -the entire line typed so far -and are given a fresh line to type on. -You may immediately begin to retype the line. -This, unfortunately, does not work after you type the -line and press \s-2RETURN\s+2. -To make corrections in lines that have been completed, -it is necessary to use the editing commands -covered in the next sessions. -.SH -Writing text to disk -.PP -You are now ready to edit the text. One common operation -is to write the text to disk as a file for safekeeping -after the session is over. -This is the only way to save information from one session to the next, -since the editor's buffer is temporary and will last only until the -end of the editing session. -Learning how to write a file to disk is second in -importance only to entering the text. -To write the contents of the buffer to a disk -file, use the command ``write'' -(or its abbreviation ``w''): -.DS I 1i -:\|\fBwrite -.R -.DE -Edit will copy the contents of the buffer to a disk file. -If the file does not yet exist, -a new file will be created automatically -and the presence of a ``[New file]'' will be noted. -The newly-created file will be given the name specified when -you entered the editor, in this case ``text''. -To confirm that the disk file has been successfully written, -edit will repeat the filename and give -the number of lines and the total -number of characters in the file. -The buffer remains unchanged by the ``write'' command. -All of the lines that were written to disk will still be -in the buffer, -should you want to modify or add to them. -.PP -Edit must have a name for the file to be written. -If you forgot to indicate the name of the file -when you began to edit, -edit will print in response to your write command: -.DS I 1i -No current filename -.DE -If this happens, you can specify the filename in a new write command: -.DS I 1i -:\|\fBwrite text -.R -.DE -After the ``write'' (or ``w''), type a space and then the name of the file. -.SH -Signing off -.PP -We have done enough for this first lesson on using the -\s-2UNIX\s0 text editor, and are ready to quit the session with edit. -To do this we type ``quit'' (or ``q'') and press \s-2RETURN\s+2: -.DS I 1i -:\|\fBwrite -.R -"text" [New file] 3 lines, 90 characters -:\|\fBquit\fR -% -.DE -The % is from \s-2UNIX\s0 to tell you that your session with edit is -over and you may command \s-2UNIX\s0 further. -Since we want -to end the entire session at the terminal, we also need to -exit from \s-2UNIX\s0. -In response to the \s-2UNIX\s0 prompt of ``\|%\|'' -type the command -.DS I 1i -%\|\fBlogout\fR -.DE -This will end your session with \s-2UNIX\s0, and will ready the -terminal for the next user. -It is always important to type \fBlogout\fR at the end of a session -to make absolutely sure no one -could accidentally stumble into your abandoned -session and thus gain access to your files, -tempting even the most honest of souls. -.sp 1 -.PP -This is the end of the first session on \s-2UNIX\s0 text editing. -.bp -.TL -Session 2 -.sp -.PP -Login with \s-2UNIX\s0 as in the first session: -.DS I 1i -login: \fBsusan\fP \fI(carriage return)\fR -Password: \fI(give password and carriage return)\fR -.if t .sp .2v -.if n .sp 1 -\&... A Message of General Interest ... -% -.DE -When you indicate you want to edit, -you can specify the name of the file you worked on last time. -This will -start edit working, and it will fetch the contents of the -file into the buffer, so that you can resume editing the same file. -When edit has copied the file into the buffer, it -will repeat its name and tell -you the number of lines and characters it contains. -Thus, -.DS I 1i -.B -% edit text -.R -"text" 3 lines, 90 characters -: -.DE -means you asked edit to fetch -the file named ``text'' for editing, -causing it to copy the -90 characters of text into the buffer. -Edit awaits -your further instructions, -and indicates this by its prompt character, the colon (:). -In this session, we will append more text to our file, -print the contents of the buffer, and learn to change the text of a line. -.SH -Adding more text to the file -.PP -If you want to add more to the end of your -text you may do so by using the append command to enter text input mode. -When ``append'' is the first command -of your editing session, -the lines you enter -are placed at the end of the buffer. -Here we'll use the abbreviation for the append command, ``a'': -.DS I 1i -:\|\fBa -This is text added in Session 2. -It doesn't mean much here, but -it does illustrate the editor. -\|\fB\s+2\&.\s-2 -.R -.DE -You may recall that once you enter append mode -using the ``a'' (or ``append'') command, -you need to type a line containing only a period (.) -to exit append mode. -.SH -Interrupt -.PP -Should you press the \s-2RUB\s+2 key (sometimes labelled \s-2DELETE\s+2) -while working with edit, -it will send this message to you: -.DS I 1i -Interrupt -: -.DE -Any command that edit might be executing -is terminated by rub or delete, -causing edit to prompt you for a new command. -If you are appending text at the time, -you will exit from append mode -and be expected to give another command. -The line of text you were typing -when the append command was interrupted -will not be entered into the buffer. -.SH -Making corrections -.PP -If while typing the line you hit an incorrect key, -recall that -you may delete the incorrect character -or cancel the entire line of input by erasing in the usual way. -Refer either -to the last few pages of Session 1 -if you need to review -the procedures for making a correction. -The most important idea to remember is that -erasing a character or cancelling a line must be done -before you press the \s-2RETURN\s+2 key. -.SH -Listing what's in the buffer (p) -.PP -Having appended text to what you wrote in Session 1, -you might want to see all the lines in the buffer. -To print the contents of the buffer, type the command: -.DS I 1i -:\|\fB1,$p -.R -.DE -The ``1''\(dg -.FS -\(dgThe numeral ``one'' is the top left-most key, -and should not be confused with the letter ``el''. -.FE -stands for line 1 of the buffer, -the ``$'' is a special symbol designating the last line -of the buffer, -and ``p'' (or \fBprint\fR) is the command to print from line 1 -to the end of the buffer. -The command ``1,$p'' gives you: -.DS I 1i -This is some sample text. -And thiss is some more text. -Text editing is strange, but nice. -This is text added in Session 2. -It doesn't mean much here, but -it does illustrate the editor. -.DE -Occasionally, you may accidentally -type a character that can't be printed, -which can be done by striking a key -while the \s-2CTRL\s0 key is pressed. -In printing lines, edit uses a special notation to -show the existence of non-printing characters. -Suppose you had introduced the non-printing character ``control-A'' -into the word ``illustrate'' -by accidently pressing the \s-2CTRL\s0 key while -typing ``a''. -This can happen on many terminals -because the \s-2CTRL\s+2 key and the ``A'' key -are beside each other. -If your finger presses between the two keys, -control-A results. -When asked to print the contents of the buffer, -edit would display -.DS I 1i -it does illustr^Ate the editor. -.DE -To represent the control-A, edit shows ``^A''. -The sequence ``^'' followed by a capital -letter stands for the one character -entered by holding down the \s-2CTRL\s0 key and typing the letter -which appears after the ``^''. -We'll soon discuss the commands that can be used -to correct this typing error. -.PP -In looking over the text we see that -``this'' is typed as ``thiss'' in the second line, -a deliberate error so we can learn to make corrections. -Let's correct the spelling. -.SH -Finding things in the buffer -.PP -In order to change something in the buffer we first need to -find it. -We can find ``thiss'' in the text we have -entered by looking at a listing -of the lines. -Physically speaking, we search the lines -of text looking for ``thiss'' and stop searching when -we have found it. -The way to tell edit to search for something -is to type it inside slash marks: -.DS I 1i -:\|\fB/thiss/ -.R -.DE -By typing -.B /thiss/ -and pressing \s-1RETURN\s0, -you instruct edit to search for ``thiss''. -If you ask edit to look for a pattern of characters -which it cannot find in the buffer, -it will respond ``Pattern not found''. -When edit finds -the characters ``thiss'', it will print the line of text -for your inspection: -.DS I 1i -And thiss is some more text. -.DE -Edit is now positioned in the buffer at the -line it just printed, -ready to make a change in the line. -.bp -.SH -The current line -.PP -Edit keeps track of the line in the buffer where it is located -at all times during an editing session. -In general, the line that has been most recently -printed, entered, or changed -is the current location in the buffer. -The editor is prepared to make changes -at the current location in the buffer, -unless you direct it to another location. -.PP -In particular, -when you bring a file into the buffer, -you will be located at the last line in the file, -where the editor left off copying the lines -from the file to the buffer. -If your first editing command is ``append'', -the lines you enter are added -to the end of the file, -after the current line \(em -the last line in the file. -.PP -You can refer to your current location in the buffer by the -symbol -period (.) usually known by the name ``dot''. -If you type ``.'' and carriage -return you will be instructing edit to print the current line: -.DS I 1i -:\|\fB\s+2\&.\s-2 -.R -And thiss is some more text. -.DE -.PP -If you want to know the number of the current line, -you can type -.B \&.= -and press \s-2RETURN\s+2, -and edit will respond with the line number: -.DS I 1i -:\|\fB\s+2.\s-2= -.R -2 -.DE -If you type the number of any line and press \s-2RETURN\s+2, -edit will position you at that line and -print its contents: -.DS I 1i -:\|\fB2 -.R -And thiss is some more text. -.DE -You should experiment with these commands -to gain experience in using them to make changes. -.SH -Numbering lines (nu) -.PP -The -.B -number (nu) -.R -command is similar to print, -giving both the number and the text of each printed line. -To see the number and the text of the current line type -.DS I 1i -:\|\fBnu -.R -\0\0\0\0\02\0\0And thiss is some more text. -.DE -Note that the shortest abbreviation for the number command is -``nu'' (and not ``n'', which is used for a different command). -You may specify a range of lines -to be listed by the number command in the same way that lines -are specified for print. -For example, \f31,$nu\f1 lists all lines in the buffer with their -corresponding line numbers. -.SH -Substitute command (s) -.PP -Now that you have found the misspelled word, -you can change it from ``thiss'' to ``this''. -As far as edit is concerned, -changing things is a matter of -substituting one thing for another. -As -.I a -stood for -.I append, -so -.I s -stands for -.I substitute. -We will use the abbreviation ``s'' to reduce the chance -of mistyping the substitute command. -This command will instruct edit to make the change: -.DS I 1i -\f32s/thiss/this/\f1 -.DE -We first indicate the line to be changed, line 2, -and then -type an ``s'' to indicate we want -edit to make a substitution. -Inside the first set of slashes -are the characters that we want to change, -followed by the characters to replace them, -and then a closing slash mark. -To summarize: -.DS I 1i -2s/ \fIwhat is to be changed\fR / \fIwhat to change it to \fR/ -.DE -If edit finds an exact match of the characters to be -changed it will make the change -.B only -in the first occurrence of the characters. -If it does not find the characters -to be changed, it will respond: -.DS I 1i -Substitute pattern match failed -.DE -indicating that your instructions could not be carried out. -When edit does find the characters that you want to change, -it will make the substitution and automatically print -the changed line, so that you can check that the correct substitution -was made. -In the example, -.DS I 1i -:\|\fB2s/thiss/this/ -.R -And this is some more text. -.DE -line 2 (and line 2 only) will be searched for the characters -``thiss'', and when the first exact match is found, ``thiss'' -will be changed to ``this''. -Strictly speaking, it was not necessary above to -specify the number of the line to be changed. -In -.DS I 1i -:\|\fBs/thiss/this/ -.R -.DE -edit will assume that we mean to change -the line where we are currently located (``.''). -In this case, -the command without a line number would have produced the same result -because we were already located -at the line we wished to change. -.PP -For another illustration of the substitute command, -let us choose the line: -.DS I 1i -Text editing is strange, but nice. -.DE -You can make this line a bit more positive -by taking out the characters ``strange, but\ '' so the line -reads: -.DS I 1i -Text editing is nice. -.DE -A command that will first position edit at the desired line -and then make the substitution is: -.DS I 1i -:\|\fB/strange/s/strange, but // -.R -.DE -.LP -What we have done here is combine our search with -our substitution. -Such combinations are perfectly legal, -and speed up editing quite a bit -once you get used to them. -That is, you do not necessarily have to use -line numbers to identify a line to edit. -Instead, you may identify the line you want to change -by asking edit to search for a specified pattern of letters -that occurs in that line. -The parts of the above command are: -.in +1i -.TS -l l. -\fB/strange/\fP tells edit to find the characters ``strange'' in the text -\fBs\fP tells edit to make a substitution -\fB/strange, but //\fP substitutes nothing at all for the characters ``strange, but '' -.TE -.in -1i -.PP -You should note the space after ``but'' in ``/strange, but /''. -If you do not indicate that the space is to be taken out, -your line will read: -.DS I 1i -.if t Text editing is nice. -.if n Text editing is nice. -.DE -which looks a little funny -because of the extra space between ``is'' and ``nice''. -Again, we realize from this that a blank space -is a real character to a computer, and in editing text -we need to be aware of spaces -within a line just as we would be aware of an ``a'' or -a ``4''. -.SH -Another way to list what's in the buffer (z) -.PP -Although the print command is useful for looking at specific lines -in the buffer, -other commands may be more convenient for -viewing large sections of text. -You can ask to see a screen full of text at a time -by using the command -.B z. -If you type -.DS I 1i -:\|\fB1z -.R -.DE -edit will start with line 1 and continue printing lines, -stopping either when the screen of -your terminal is full -or when the last line in the buffer has been printed. -If you want to read the next segment of text, type the command -.DS I 1i -:\|\fBz -.DE -If no starting line number is given for the z command, -printing will start at the ``current'' line, in this case the -last line printed. -Viewing lines in the buffer one screen full at a time -is known as \fIpaging\fR. -Paging can also be used to print -a section of text on a hard-copy terminal. -.SH -Saving the modified text -.PP -This seems to be a good place to pause in our work, -and so we should end the second session. -If you (in haste) type ``q'' to quit the session -your dialogue with edit will be: -.DS I 1i -:\|\fBq -.R -No write since last change (:quit! overrides) -: -.DE -This is edit's warning that you have not written -the modified contents of the buffer to disk. -You run the risk of losing the work you did -during the editing session since you typed the latest write -command. -Because in this lesson we have not written -to disk at all, everything we have done -would have been lost -if edit had obeyed the \fBq\fR command. -If you did not want to save the work done during -this editing session, you would have to type ``q!'' -or (``quit!'') -to confirm that you indeed wanted to end the session -immediately, -leaving the file as it was -after the most recent ``write'' command. -However, -since you want to save what -you have edited, you need to type: -.DS I 1i -:\|\fBw -.R -"text" 6 lines, 171 characters -.DE -and then follow with the commands to quit and logout: -.DS I 1i -:\|\fBq -% \fBlogout\fR -.DE -and hang up the phone or turn off the terminal when -\s-2UNIX\s0 asks for a name. -Terminals connected to the port selector -will stop after the logout command, -and pressing keys on the keyboard will do nothing. -.sp 1 -.PP -This is the end of the second session on \s-2UNIX\s0 text editing. -.bp -.TL -Session 3 -.SH -Bringing text into the buffer (e) -.PP -Login to \s-2UNIX\s0 and make contact with edit. -You should try to login without -looking at the notes, but if you must -then by all means do. -.PP -Did you remember to give the name of the file -you wanted to edit? -That is, did you type -.DS I 1i -% \fBedit text\fR -.DE -or simply -.DS I 1i -% \fBedit\fR -.DE -Both ways get you in contact with edit, but the first way -will bring a copy of the file named ``text'' into -the buffer. -If you did forget to tell edit the name of your file, -you can get it into the buffer by -typing: -.DS I 1i -:\|\fBe text -.R -"text" 6 lines, 171 characters -.DE -The command -.B edit, -which may be abbreviated \fBe\fR, -tells edit that you want -to erase anything that might already be in -the buffer and bring a copy of the file ``text'' into the buffer -for editing. -You may also use the edit (e) command to change files in -the middle of an editing session, -or to give edit the name of a new file that you want to create. -Because the edit command clears the buffer, -you will receive a warning if you try to edit a new file without -having saved a copy of the old file. -This gives you a chance to write the contents of the buffer to disk -before editing the next file. -.SH -Moving text in the buffer (m) -.PP -Edit allows you to move lines of text -from one location in the buffer to another -by means of the -.B move -(\fBm\fR) command. -The first two examples are for illustration only, -though after you have read this Session -you are welcome to return to them for practice. -The command -.DS I 1i -:\|\fB2,4m$ -.R -.DE -directs edit to move lines 2, 3, and 4 -to the end of the buffer ($). -The format for the move command is that you specify -the first line to be moved, the last line to be moved, -the move command ``m'', and the line after which -the moved text is to be placed. -So, -.DS I 1i -:\|\fB1,3m6 -.R -.DE -would instruct edit to move lines 1 through 3 (inclusive) -to a location after line 6 in the buffer. -To move only one line, say, line 4, -to a location in the buffer after line 5, -the command would be ``4m5''. -.PP -Let's move some text using the command: -.DS I 1i -:\|\fB5,$m1 -.R -2 lines moved -it does illustrate the editor. -.DE -After executing a command that moves more than one line of the buffer, -edit tells how many lines were affected by the move -and prints the last moved line for your inspection. -If you want to see more than just the last line, -you can then -use the print (p), z, or number (nu) command to view more text. -The buffer should now contain: -.DS I 1i -This is some sample text. -It doesn't mean much here, but -it does illustrate the editor. -And this is some more text. -Text editing is nice. -This is text added in Session 2. -.DE -You can restore the original order by typing: -.DS I 1i -:\|\fB4,$m1 -.R -.DE -or, combining context searching and the move command: -.DS I 1i -:\|\fB/And this is some/,/This is text/m/This is some sample/ -.R -.DE -(Do not type both examples here!) -The problem with combining context searching -with the move command -is that your chance of making a typing error -in such a long command is greater than -if you type line numbers. -.SH -Copying lines (copy) -.PP -The -.B copy -command -is used to make a second copy of specified lines, -leaving the original lines where they were. -Copy -has the same format as the move command, for example: -.DS I 1i -:\|\fB2,5copy $ -.R -.DE -makes a copy of lines 2 through 5, -placing the added lines after the buffer's end ($). -Experiment with the copy command -so that you can become familiar with how it works. -Note that the shortest abbreviation for copy is -\f3co\f1 (and -not the letter ``c'', which has another meaning). -.SH -Deleting lines (d) -.PP -Suppose you want to delete -the line -.DS I 1i -This is text added in Session 2. -.DE -from the buffer. -If you know the number of the line to be deleted, -you can type -that number followed by -\fBdelete\fR or \fBd\fR. -This example deletes line 4, -which is ``This is text added in Session 2.'' -if you typed the commands -suggested so far. -.DS I 1i -:\|\fB4d -.R -It doesn't mean much here, but -.DE -Here ``4'' is the number of the line to be deleted, -and ``delete'' or ``d'' is the command to delete the line. -After executing the delete command, -edit prints the line that has become the current line (``.''). -.PP -If you do not happen to know the line number -you can search for the line and then delete it using this -sequence of commands: -.DS I 1i -:\|\fB/added in Session 2./ -.R -This is text added in Session 2. -:\|\fBd -.R -It doesn't mean much here, but -.DE -The ``/added in Session 2./'' -asks edit to locate and print -the line containing the indicated text, -starting its search at the current line -and moving line by line -until it finds the text. -Once you are sure that you have correctly specified the line -you want to delete, -you can enter the delete (d) command. -In this case it is not necessary to -specify a line number before the ``d''. -If no line number is given, -edit deletes the current line (``.''), -that is, the line found by our search. -After the deletion, your buffer should contain: -.DS I 1i -This is some sample text. -And this is some more text. -Text editing is nice. -It doesn't mean much here, but -it does illustrate the editor. -And this is some more text. -Text editing is nice. -This is text added in Session 2. -It doesn't mean much here, but -.DE -To delete both lines 2 and 3: -.DS I 1i -And this is some more text. -Text editing is nice. -.DE -you type -.DS I 1i -:\|\f32,3d\f1 -2 lines deleted -.DE -which specifies the range of lines from 2 to 3, -and the operation on those lines \(em ``d'' for delete. -If you delete more than one line -you will receive a message -telling you the number of lines deleted, -as indicated in the example above. -.PP -The previous example assumes that you know the line numbers for -the lines to be deleted. -If you do not you might combine the search command -with the delete command: -.DS I 1i -:\|\fB/And this is some/,/Text editing is nice./d -.R -.DE -.SH -A word or two of caution -.PP -In using the search function to locate lines to -be deleted you should be -.B -absolutely sure -.R -the characters you give as the basis for the search -will take edit to the line you want deleted. -Edit will search for the first -occurrence of the characters starting from where -you last edited \- -that is, from the line you see printed if you type dot (.). -.PP -A search based on too few -characters may result in the wrong lines being deleted, -which edit will do as easily as if you had meant it. -For this reason, it is usually safer -to specify the search and then delete in two separate steps, -at least until you become familiar enough with using the editor -that you understand how best to specify searches. -For a beginner it is not a bad idea to double-check -each command before pressing \s-2RETURN\s+2 to send the command on its way. -.SH -Undo (u) to the rescue -.PP -The -.B -undo (u) -.R -command has the ability to -reverse the effects of the last command that changed the buffer. -To undo the previous command, type -``u'' or ``undo''. -Undo can rescue -the contents of the buffer from many an unfortunate mistake. -However, its powers are not unlimited, -so it is still wise to be reasonably -careful about the commands you give. -.PP -It is possible to undo only commands which -have the power to change the buffer \(em for example, -delete, append, move, copy, substitute, and even undo itself. -The commands write (w) and edit (e), which interact with disk files, -cannot be undone, nor can commands that do not change -the buffer, such as print. -Most importantly, -the -.B only -command that can be reversed by undo -is the -last ``undo-able'' command you typed. -You can use control-H and @ to change -commands while you are typing them, -and undo to reverse the effect of the commands -after you have typed them and pressed \s-2RETURN\s+2. -.PP -To illustrate, -let's issue an undo command. -Recall that the last buffer-changing command we gave deleted -the lines formerly numbered 2 and 3. -Typing undo at this moment will reverse the effects -of the deletion, causing those two lines to be -replaced in the buffer. -.DS I 1i -:\|\fBu -.R -2 more lines in file after undo -And this is some more text. -.DE -Here again, edit informs you if the command affects more -than one line, -and prints -the text of the line which is now ``dot'' (the current line). -.SH -More about the dot (.) and buffer end ($) -.PP -The function assumed by the symbol dot depends on its context. -It can be used: -.IP -1. to exit from append mode; we type dot (and only a dot) on -a line and press \s-2RETURN\s+2; -.IP -2. to refer to the line we are at in the buffer. -.LP -Dot can also be combined with the equal sign to get -the number of the line currently being edited: -.DS I 1i -:\|\fB\&.= -.R -.DE -If we type ``\fB.\fR='' we are asking for the number of the line, -and if we type ``\fB.\fR'' we are asking for the text of the line. -.PP -In this editing session and the last, we used the dollar -sign to indicate the end of the buffer -in commands such as print, copy, and move. -The dollar sign as a command asks edit to print the last -line in the buffer. -If the dollar sign is combined with the equal sign (\f3$=\f1) -edit will print the line number corresponding to the -last line in the buffer. -.PP -``\fB.\fR'' and ``$'', then, represent line numbers. -Whenever appropriate, these symbols can be used in -place of line numbers in commands. -For example -.DS I 1i -:\|\fB\s+2.\s-2,$d -.R -.DE -instructs edit to delete all lines from the current line (\fB.\fR) -to the end of the buffer. -.SH -Moving around in the buffer (+ and \-) -.PP -When you are editing -you often want -to go back and re-read a previous line. -You could specify a context search for a line you want to -read if you remember some of its text, -but if you simply want to see what was written a few, say 3, lines -ago, you can type -.DS I 1i -\-3p -.DE -This tells edit to move back to a position 3 lines -before the current line (.) -and print that line. -You can move forward in the buffer similarly: -.DS I 1i -+2p -.DE -instructs edit to print the line that is 2 -ahead of your current position. -.PP -You may use ``+'' and ``\-'' in any command where edit -accepts line numbers. -Line numbers specified with ``+'' or ``\-'' -can be combined to print a range of lines. -The command -.DS I 1i -:\|\fB\-1,+2copy$ -.R -.DE -makes a copy of 4 lines: the current line, the line before it, -and the two after it. -The copied lines will be placed after the last line -in the buffer ($), -and the original lines referred to by ``\-1'' and ``+2'' -remain where they are. -.PP -Try typing only ``\-''; you will move back one line just as -if you had typed ``\-1p''. -Typing the command ``+'' works similarly. -You might also try typing a few plus or minus signs in a row -(such as ``+++'') to see edit's response. -Typing \s-2RETURN\s+2 alone on a line is the equivalent -of typing ``+1p''; it will move you one line ahead in the buffer -and print that line. -.PP -If you are at the last line of the buffer and try -to move further ahead, perhaps by typing a ``+'' or -a carriage return alone on the line, -edit will remind you that you are at the end of the buffer: -.sp -.nf -.ti 1i -At end-of-file -.br -or -.ti 1i -Not that many lines in buffer -.fi -.LP -Similarly, if you try to move to a position before the first line, -edit will print one of these messages: -.sp -.nf -.ti 1i -Nonzero address required on this command -.br -or -.ti 1i -Negative address \- first buffer line is 1 -.fi -.LP -The number associated with a buffer line is the line's ``address'', -in that it can be used to locate the line. -.SH -Changing lines (c) -.PP -You can also delete certain lines and -insert new text in their place. -This can be accomplished easily with the -.B "change (c)" -command. -The change command instructs edit to delete specified lines -and then switch to text input mode to -accept the text that will replace them. -Let's say you want to change the first two lines in the buffer: -.DS I 1i -This is some sample text. -And this is some more text. -.DE -to read -.DS I 1i -This text was created with the \s-2UNIX\s0 text editor. -.DE -To do so, you type: -.DS I 1i -:\|\fB1,2c -.R -2 lines changed -.B -This text was created with the \s-2UNIX\s0 text editor. -\s+2\&.\s-2 -.R -: -.DE -In the command -.B 1,2c -we specify that we want to change -the range of lines beginning with 1 and ending with 2 -by giving line numbers as with the print command. -These lines will be deleted. -After you type \s-2RETURN\s+2 to end the change command, -edit notifies you if more than one line will be changed -and places you in text input mode. -Any text typed on the following lines will be inserted into -the position where lines were deleted by the change command. -.B -You will remain in text input mode until you exit in the usual way, -by typing a period alone on a line. -.R -Note that the number of lines added to the buffer need not be -the same as the number of lines deleted. -.sp 1 -.PP -This is the end of the third session on text editing with \s-2UNIX\s0. -.bp -.SH -.ce 1 -\s+2Session 4\s0 -.sp -.PP -This lesson covers several topics, starting with -commands that apply throughout the buffer, -characters with special meanings, -and how to issue \s-2UNIX\s0 commands while in the editor. -The next topics deal with files: -more on reading and writing, -and methods of recovering files lost in a crash. -The final section suggests sources of further information. -.SH -Making commands global (g) -.PP -One disadvantage to the commands we have used for -searching or substituting is that if you -have a number of instances of a word to change -it appears that you have to type the command -repeatedly, once for -each time the change needs to be made. -Edit, however, provides a way to make commands -apply to the entire contents of the buffer \- -the -.B -global (g) -.R -command. -.PP -To print all lines -containing a certain sequence of characters -(say, ``text'') -the command is: -.DS I 1i -:\|\fBg/text/p -.R -.DE -The ``g'' instructs edit to -make a global search for all lines -in the buffer containing the characters ``text''. -The ``p'' prints the lines found. -.PP -To issue a global command, start by typing a ``g'' and then a search -pattern identifying -the lines to be affected. -Then, on the same line, type the command to be -executed for the identified lines. -Global substitutions are frequently useful. -For example, -to change all instances of the word ``text'' to the word ``material'' -the command would be a combination of the global search and the -substitute command: -.DS I 1i -:\|\fBg/text/s/text/material/g -.R -.DE -Note the ``g'' at the end of the global command, -which instructs edit to change -each and every instance of ``text'' to ``material''. -If you do not type the ``g'' at the end of the command -only the -.I first -instance of ``text'' \fIin each line\fR will be changed -(the normal result of the substitute command). -The ``g'' at the end of the command is independent of the ``g'' -at the beginning. -You may give a command such as: -.DS I 1i -:\|\fB5s/text/material/g -.R -.DE -to change every instance of ``text'' in line 5 alone. -Further, neither command will change ``text'' to ``material'' -if ``Text'' begins with a capital rather than a lower-case -.I t. -.PP -Edit does not automatically print the lines modified by a -global command. -If you want the lines to be printed, type a ``p'' -at the end of the global command: -.DS I 1i -:\|\fBg/text/s/text/material/gp -.R -.DE -You should be careful -about using the global command in combination with any other \- -in essence, be sure of what you are telling edit to do -to the entire buffer. -For example, -.DS I 1i -:\|\fBg/ /d -.R -72 less lines in file after global -.DE -will delete every line containing a blank anywhere in it. -This could adversely affect -your document, since most lines have spaces between words -and thus would be deleted. -After executing the global command, -edit will print a warning if the command added or deleted more than one line. -Fortunately, the undo command can reverse -the effects of a global command. -You should experiment with the global command -on a small file of text to see what it can do for you. -.SH -More about searching and substituting -.PP -In using slashes to identify a character string -that we want to search for or change, -we have always specified the exact characters. -There is a less tedious way to -repeat the same string of characters. -To change ``text'' to ``texts'' we may type either -.DS I 1i -:\|\fB/text/s/text/texts/ -.R -.DE -as we have done in the past, -or a somewhat abbreviated command: -.DS I 1i -:\|\fB/text/s//texts/ -.R -.DE -In this example, the characters to be changed -are not specified \- -there are no characters, not even a space, -between the two slash marks -that indicate what is to be changed. -This lack of characters between the slashes -is taken by the editor to mean -``use the characters we last searched for as the characters to be changed.'' -.PP -Similarly, the last context search may be repeated -by typing a pair of slashes with nothing between them: -.DS I 1i -:\|\fB/does/ -.R -It doesn't mean much here, but -:\|\fB// -.R -it does illustrate the editor. -.DE -(You should note that the search command found the characters ``does'' -in the word ``doesn't'' in the first search request.) -Because no characters are specified for the second search, -the editor scans the buffer for the next occurrence of the -characters ``does''. -.PP -Edit normally searches forward through the buffer, -wrapping around from the end of the buffer to the beginning, -until the specified character string is found. -If you want to search in the reverse direction, -use question marks (?) instead of slashes -to surround the characters you are searching for. -.PP -It is also possible -to repeat the last substitution -without having to retype the entire command. -An ampersand (&) used as a command -repeats the most recent substitute command, -using the same search and replacement patterns. -After altering the current line by typing -.DS I 1i -:\|\fBs/text/texts/ -.R -.DE -you type -.DS I 1i -:\|\fB/text/& -.R -.DE -or simply -.DS I 1i -:\|\fB//& -.R -.DE -to make the same change on the next line in the buffer -containing the characters ``text''. -.SH -Special characters -.PP -Two characters have special meanings when -used in specifying searches: ``$'' and ``^''. -``$'' is taken by the editor to mean ``end of the line'' -and is used to identify strings -that occur at the end of a line. -.DS I 1i -:\|\fBg/text.$/s//material./p -.R -.DE -tells the editor to search for all lines ending in ``text.'' -(and nothing else, not even a blank space), -to change each final ``text.'' to ``material.'', -and print the changed lines. -.PP -The symbol ``^'' indicates the beginning of a line. -Thus, -.DS I 1i -:\|\fBs/^/1. / -.R -.DE -instructs the editor to insert ``1.'' and a space at the beginning -of the current line. -.PP -The characters ``$'' and ``^'' have special meanings only in the context -of searching. -At other times, they are ordinary characters. -If you ever need to search for a character that has a special meaning, -you must indicate that the -character is to lose temporarily -its special significance by typing another special character, -the backslash (\\), before it. -.DS I 1i -:\|\fBs/\\\\\&$/dollar/ -.R -.DE -looks for the character ``$'' in the current -line and replaces it by the word ``dollar''. -Were it not for the backslash, the ``$'' would have represented -``the end of the line'' in your search -rather than the character ``$''. -The backslash retains its special significance -unless it is preceded by another backslash. -.SH -Issuing \s-2UNIX\s0 commands from the editor -.PP -After creating several files with the editor, -you may want to delete files -no longer useful to you or ask for a list of your files. -Removing and listing files are not functions of the editor, -and so they require the use of \s-2UNIX\s0 system commands -(also referred to as ``shell'' commands, as -``shell'' is the name of the program that processes \s-2UNIX\s0 commands). -You do not need to quit the editor to execute a \s-2UNIX\s0 command -as long as you indicate that it -is to be sent to the shell for execution. -To use the \s-2UNIX\s0 command -.B rm -to remove the file named ``junk'' type: -.DS I 1i -:\|\fB!rm junk -.R -! -: -.DE -The exclamation mark (!) -indicates that the rest of the line is to be processed as a shell command. -If the buffer contents have not been written since the last change, -a warning will be printed before the command is executed: -.DS I 1i -[No write since last change] -.DE -The editor prints a ``!'' when the command is completed. -Other tutorials describe useful features of the system, -of which an editor is only one part. -.SH -Filenames and file manipulation -.PP -Throughout each editing session, -edit keeps track of the name of the file being edited as the -.I "current filename." -Edit remembers as the current filename the name given -when you entered the editor. -The current filename changes whenever the edit (e) command -is used to specify a new file. -Once edit has recorded a current filename, -it inserts that name into any command where a filename has been omitted. -If a write command does not specify a file, -edit, as we have seen, supplies the current filename. -If you are editing a file named ``draft3'' having 283 lines in it, -you can have the editor write onto a different file -by including its name in the write command: -.DS I 1i -:\fB\|w chapter3 -.R -"chapter3" [new file] 283 lines, 8698 characters -.DE -The current filename remembered by the editor -.I -will not be changed as a result of the write command. -.R -Thus, if the next write command -does not specify a name, -edit will write onto the current file (``draft3'') -and not onto the file ``chapter3''. -.SH -The file (f) command -.PP -To ask for the current filename, type -.B file -(or -.B f ). -In response, the editor provides current information about the buffer, -including the filename, your current position, the number of -lines in the buffer, -and the percent of the distance through the file -your current location is. -.DS I 1i -:\|\fBf -.R -"text" [Modified] line 3 of 4 --75%-- -.DE -.\"The expression ``[Edited]'' indicates that the buffer contains -.\"either the editor's copy of the existing file ``text'' -.\"or a file which you are just now creating. -If the contents of the buffer have changed -since the last time the file was written, -the editor will tell you that the file has been ``[Modified]''. -After you save the changes by writing onto a disk file, -the buffer will no longer be considered modified: -.DS I 1i -:\|\fBw -.R -"text" 4 lines, 88 characters -:\|\fBf -.R -"text" line 3 of 4 --75%-- -.DE -.SH -Reading additional files (r) -.PP -The -\f3read (r)\f1 command allows you to add the contents of a file -to the buffer -at a specified location, -essentially copying new lines -between two existing lines. -To use it, specify the line after which the new text will be placed, -the \f3read (r)\f1 command, -and then the name of the file. -If you have a file named ``example'', the command -.DS I 1i -:\|\fB$r example -.R -"example" 18 lines, 473 characters -.DE -reads the file ``example'' -and adds it to the buffer after the last line. -The current filename is not changed by the read command. -.SH -Writing parts of the buffer -.PP -The -.B -write (w) -.R -command can write all or part of the buffer -to a file you specify. -We are already familiar with -writing the entire contents of the -buffer to a disk file. -To write only part of the buffer onto a file, -indicate the beginning and ending lines before the write command, -for example -.DS I 1i -:\|\fB45,$w ending -.R -.DE -Here all lines from 45 through the end of the buffer -are written onto the file named -.I ending. -The lines remain in the buffer -as part of the document you are editing, -and you may continue to edit the entire buffer. -Your original file is unaffected -by your command to write part of the buffer -to another file. -Edit still remembers whether you have saved changes to the buffer -in your original file or not. -.SH -Recovering files -.PP -Although it does not happen very often, -there are times \s-2UNIX\s+2 stops working -because of some malfunction. -This situation is known as a \fIcrash\fR. -Under most circumstances, -edit's crash recovery feature -is able to save work to within a few lines of changes -before a crash (or an accidental phone hang up). -If you lose the contents of an editing buffer in a system crash, -you will normally receive mail when you login that gives -the name of the recovered file. -To recover the file, -enter the editor and type the command -.B recover -(\fBrec\fR), -followed by the name of the lost file. -For example, -to recover the buffer for an edit session -involving the file ``chap6'', the command is: -.DS I 1i -.R -:\|\fBrecover chap6 -.R -.DE -Recover is sometimes unable to save the entire buffer successfully, -so always check the contents of the saved buffer carefully -before writing it back onto the original file. -For best results, -write the buffer to a new file temporarily -so you can examine it without risk to the original file. -Unfortunately, -you cannot use the recover command -to retrieve a file you removed -using the shell command \f3rm\f1. -.SH -Other recovery techniques -.PP -If something goes wrong when you are using the editor, -it may be possible to save your work by using the command -.B preserve -(\fBpre\fR), -which saves the buffer as if the system had crashed. -If you are writing a file and you get the message -``Quota exceeded'', you have tried to use more disk storage -than is allotted to your account. -.I -Proceed with caution -.R -because it is likely that only a part -of the editor's buffer is now present in the file you tried to write. -In this case you should use the shell escape from the editor (!) -to remove some files you don't need and try to write -the file again. -If this is not possible and you cannot find someone to help you, -enter the command -.DS I 1i -:\|\fBpreserve -.R -.DE -and wait for the reply, -.DS I 1i -File preserved. -.DE -If you do not receive this reply, -seek help immediately. -Do not simply leave the editor. -If you do, the buffer will be lost, -and you may not be able to save your file. -If the reply is ``File preserved.'' -you can leave the editor -(or logout) -to remedy the situation. -After a preserve, you can use the recover command -once the problem has been corrected, -or the \fB\-r\fR option of the edit command -if you leave the editor and want to return. -.PP -If you make an undesirable change to the buffer -and type a write command before discovering your mistake, -the modified version will replace any previous version of the file. -Should you ever lose a good version of a document in this way, -do not panic and leave the editor. -As long as you stay in the editor, -the contents of the buffer remain accessible. -Depending on the nature of the problem, -it may be possible -to restore the buffer to a more complete -state with the undo command. -After fixing the damaged buffer, you can again write the file -to disk. -.SH -Further reading and other information -.PP -Edit is an editor designed for beginning and casual users. -It is actually a version of a more powerful editor called -.I ex. -These lessons are intended to introduce you to the editor -and its more commonly-used commands. -We have not covered all of the editor's commands, -but a selection of commands -that should be sufficient to accomplish most of your editing tasks. -You can find out more about the editor in the -.I -Ex Reference Manual, -.R -which is applicable to both -.I ex -and -.I edit. -One way to become familiar with the manual is to begin by reading -the description of commands that you already know. -.bd I 3 -.SH -Using -.I ex -.fl -.bd I -.PP -As you become more experienced with using the editor, -you may still find that edit continues to meet your needs. -However, should you become interested in using -.I ex, -it is easy to switch. -To begin an editing session with -.I ex, -use the name -.B ex -in your command instead of -.B edit. -.PP -Edit commands also work in -.I ex, -but the editing environment is somewhat different. -You should be aware of a few differences -between -.I ex -and -.I edit. -In edit, only the characters ``^'', ``$'', and ``\\'' have -special meanings in searching the buffer -or indicating characters to be changed by a substitute command. -Several additional characters have special -meanings in ex, as described in the -.I -Ex Reference Manual. -.R -Another feature of the edit environment prevents users from -accidently entering two alternative modes of editing, -.I open -and -.I visual, -in which -the editor behaves quite differently from normal command mode. -If you are using ex and you encounter strange behavior, -you may have accidently entered open mode by typing ``o''. -Type the \s-2ESC\s0 key and then a ``Q'' -to get out of open or visual mode and back into -the regular editor command mode. -The document -.I -An Introduction to Display Editing with Vi\|\| -.R -provide full details of visual mode. -.bp -.SH -.ce 1 -\s+2Index\s0 -.LP -.sp 2 -.2C -.nf -addressing, \fIsee\fR line numbers -ampersand, 20 -append mode, 6-7 -append (a) command, 6, 7, 9 -``At end of file'' (message), 18 -backslash (\\), 21 -buffer, 3 -caret (^), 10, 20 -change (c) command, 18 -command mode, 5-6 -``Command not found'' (message), 6 -context search, 10-12, 19-21 -control characters (``^'' notation), 10 -control-H, 7 -copy (co) command, 15 -corrections, 7, 16 -current filename, 21 -current line (\|.\|), 11, 17 -delete (d) command, 15-16 -dial-up, 5 -disk, 3 -documentation, 3, 23 -dollar ($), 10, 11, 17, 20-21 -dot (\f3\|.\|\f1) 11, 17 -edit (text editor), 3, 5, 23 -edit (e) command, 5, 9, 14 -editing commands: -.in +.25i -append (a), 6, 7, 9 -change (c), 18 -copy (co), 15 -delete (d), 15-16 -edit (text editor), 3, 5, 23 -edit (e), 5, 9, 14 -file (f), 21-22 -global (g), 19 -move (m), 14-15 -number (nu), 11 -preserve (pre), 22-23 -print (p), 10 -quit (q), 8, 13 -read (r), 22 -recover (rec), 22, 23 -substitute (s), 11-12, 19, 20 -undo (u), 16-17, 23 -write (w), 8, 13, 21, 22 -z, 12-13 -! (shell escape), 21 -$=, 17 -+, 17 -\-, 17 -//, 12, 20 -??, 20 -\&., 11, 17 -\&.=, 11, 17 -.in -.25i -entering text, 3, 6-7 -erasing -.in +.25i -characters (^H), 7 -lines (@), 7 -.in -.25i -error corrections, 7, 16 -ex (text editor), 23 -\fIEx Reference Manual\fR, 23 -exclamation (!), 21 -file, 3 -file (f) command, 21-22 -file recovery, 22-23 -filename, 3, 21 -global (g) command, 19 -input mode, 6-7 -Interrupt (message), 9 -line numbers, \fIsee also\fR current line -.in +.25i -dollar sign ($), 10, 11, 17 -dot (\|.\|), 11, 17 -relative (+ and \-), 17 -.in -.25i -list, 10 -logging in, 4-6 -logging out, 8 -``Login incorrect'' (message), 5 -minus (\-), 17 -move (m) command, 14-15 -``Negative address\(emfirst buffer line is 1'' (message), 18 -``No current filename'' (message), 8 -``No such file or directory'' (message), 5, 6 -``No write since last change'' (message), 21 -non-printing characters, 10 -``Nonzero address required'' (message), 18 -``Not an editor command'' (message), 6 -``Not that many lines in buffer'' (message), 18 -number (nu) command, 11 -password, 5 -period (\|.\|), 11, 17 -plus (+), 17 -preserve (pre) command, 22-23 -print (p) command, 10 -program, 3 -prompts -.in .25i -% (\s-2UNIX\s0), 5 -: (edit), 5, 6, 7 -\0 (append), 7 -.in -.25i -question (?), 20 -quit (q) command, 8, 13 -read (r) command, 22 -recover (rec) command, 22, 23 -recovery, \fIsee\fR\| file recovery -references, 3, 23 -remove (rm) command, 21, 22 -reverse command effects (undo), 16-17, 23 -searching, 10-12, 19-21 -shell, 21 -shell escape (!), 21 -slash (/), 11-12, 20 -special characters (^, $, \\), 10, 11, 17, 20-21 -substitute (s) command, 11-12, 19, 20 -terminals, 4-5 -text input mode, 7 -undo (u) command, 16-17, 23 -\s-1UNIX\s0, 3 -write (w) command, 8, 13, 21, 22 -z command, 12-13 - |