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diff --git a/runtime/doc/usr_12.txt b/runtime/doc/usr_12.txt new file mode 100644 index 0000000..6da0830 --- /dev/null +++ b/runtime/doc/usr_12.txt @@ -0,0 +1,358 @@ +*usr_12.txt* For Vim version 8.1. Last change: 2017 Aug 11 + + VIM USER MANUAL - by Bram Moolenaar + + Clever tricks + + +By combining several commands you can make Vim do nearly everything. In this +chapter a number of useful combinations will be presented. This uses the +commands introduced in the previous chapters and a few more. + +|12.1| Replace a word +|12.2| Change "Last, First" to "First Last" +|12.3| Sort a list +|12.4| Reverse line order +|12.5| Count words +|12.6| Find a man page +|12.7| Trim blanks +|12.8| Find where a word is used + + Next chapter: |usr_20.txt| Typing command-line commands quickly + Previous chapter: |usr_11.txt| Recovering from a crash +Table of contents: |usr_toc.txt| + +============================================================================== +*12.1* Replace a word + +The substitute command can be used to replace all occurrences of a word with +another word: > + + :%s/four/4/g + +The "%" range means to replace in all lines. The "g" flag at the end causes +all words in a line to be replaced. + This will not do the right thing if your file also contains "thirtyfour". +It would be replaced with "thirty4". To avoid this, use the "\<" item to +match the start of a word: > + + :%s/\<four/4/g + +Obviously, this still goes wrong on "fourteen". Use "\>" to match the end of +a word: > + + :%s/\<four\>/4/g + +If you are programming, you might want to replace "four" in comments, but not +in the code. Since this is difficult to specify, add the "c" flag to have the +substitute command prompt you for each replacement: > + + + :%s/\<four\>/4/gc + + +REPLACING IN SEVERAL FILES + +Suppose you want to replace a word in more than one file. You could edit each +file and type the command manually. It's a lot faster to use record and +playback. + Let's assume you have a directory with C++ files, all ending in ".cpp". +There is a function called "GetResp" that you want to rename to "GetAnswer". + + vim *.cpp Start Vim, defining the argument list to + contain all the C++ files. You are now in the + first file. + qq Start recording into the q register + :%s/\<GetResp\>/GetAnswer/g + Do the replacements in the first file. + :wnext Write this file and move to the next one. + q Stop recording. + @q Execute the q register. This will replay the + substitution and ":wnext". You can verify + that this doesn't produce an error message. + 999@q Execute the q register on the remaining files. + +At the last file you will get an error message, because ":wnext" cannot move +to the next file. This stops the execution, and everything is done. + + Note: + When playing back a recorded sequence, an error stops the execution. + Therefore, make sure you don't get an error message when recording. + +There is one catch: If one of the .cpp files does not contain the word +"GetResp", you will get an error and replacing will stop. To avoid this, add +the "e" flag to the substitute command: > + + :%s/\<GetResp\>/GetAnswer/ge + +The "e" flag tells ":substitute" that not finding a match is not an error. + +============================================================================== +*12.2* Change "Last, First" to "First Last" + +You have a list of names in this form: + + Doe, John ~ + Smith, Peter ~ + +You want to change that to: + + John Doe ~ + Peter Smith ~ + +This can be done with just one command: > + + :%s/\([^,]*\), \(.*\)/\2 \1/ + +Let's break this down in parts. Obviously it starts with a substitute +command. The "%" is the line range, which stands for the whole file. Thus +the substitution is done in every line in the file. + The arguments for the substitute command are "/from/to/". The slashes +separate the "from" pattern and the "to" string. This is what the "from" +pattern contains: + \([^,]*\), \(.*\) ~ + + The first part between \( \) matches "Last" \( \) + match anything but a comma [^,] + any number of times * + matches ", " literally , + The second part between \( \) matches "First" \( \) + any character . + any number of times * + +In the "to" part we have "\2" and "\1". These are called backreferences. +They refer to the text matched by the "\( \)" parts in the pattern. "\2" +refers to the text matched by the second "\( \)", which is the "First" name. +"\1" refers to the first "\( \)", which is the "Last" name. + You can use up to nine backreferences in the "to" part of a substitute +command. "\0" stands for the whole matched pattern. There are a few more +special items in a substitute command, see |sub-replace-special|. + +============================================================================== +*12.3* Sort a list + +In a Makefile you often have a list of files. For example: + + OBJS = \ ~ + version.o \ ~ + pch.o \ ~ + getopt.o \ ~ + util.o \ ~ + getopt1.o \ ~ + inp.o \ ~ + patch.o \ ~ + backup.o ~ + +To sort this list, filter the text through the external sort command: > + + /^OBJS + j + :.,/^$/-1!sort + +This goes to the first line, where "OBJS" is the first thing in the line. +Then it goes one line down and filters the lines until the next empty line. +You could also select the lines in Visual mode and then use "!sort". That's +easier to type, but more work when there are many lines. + The result is this: + + OBJS = \ ~ + backup.o ~ + getopt.o \ ~ + getopt1.o \ ~ + inp.o \ ~ + patch.o \ ~ + pch.o \ ~ + util.o \ ~ + version.o \ ~ + + +Notice that a backslash at the end of each line is used to indicate the line +continues. After sorting, this is wrong! The "backup.o" line that was at +the end didn't have a backslash. Now that it sorts to another place, it +must have a backslash. + The simplest solution is to add the backslash with "A \<Esc>". You can +keep the backslash in the last line, if you make sure an empty line comes +after it. That way you don't have this problem again. + +============================================================================== +*12.4* Reverse line order + +The |:global| command can be combined with the |:move| command to move all the +lines before the first line, resulting in a reversed file. The command is: > + + :global/^/m 0 + +Abbreviated: > + + :g/^/m 0 + +The "^" regular expression matches the beginning of the line (even if the line +is blank). The |:move| command moves the matching line to after the mythical +zeroth line, so the current matching line becomes the first line of the file. +As the |:global| command is not confused by the changing line numbering, +|:global| proceeds to match all remaining lines of the file and puts each as +the first. + +This also works on a range of lines. First move to above the first line and +mark it with "mt". Then move the cursor to the last line in the range and +type: > + + :'t+1,.g/^/m 't + +============================================================================== +*12.5* Count words + +Sometimes you have to write a text with a maximum number of words. Vim can +count the words for you. + When the whole file is what you want to count the words in, use this +command: > + + g CTRL-G + +Do not type a space after the g, this is just used here to make the command +easy to read. + The output looks like this: + + Col 1 of 0; Line 141 of 157; Word 748 of 774; Byte 4489 of 4976 ~ + +You can see on which word you are (748), and the total number of words in the +file (774). + +When the text is only part of a file, you could move to the start of the text, +type "g CTRL-G", move to the end of the text, type "g CTRL-G" again, and then +use your brain to compute the difference in the word position. That's a good +exercise, but there is an easier way. With Visual mode, select the text you +want to count words in. Then type g CTRL-G. The result: + + Selected 5 of 293 Lines; 70 of 1884 Words; 359 of 10928 Bytes ~ + +For other ways to count words, lines and other items, see |count-items|. + +============================================================================== +*12.6* Find a man page *find-manpage* + +While editing a shell script or C program, you are using a command or function +that you want to find the man page for (this is on Unix). Let's first use a +simple way: Move the cursor to the word you want to find help on and press > + + K + +Vim will run the external "man" program on the word. If the man page is +found, it is displayed. This uses the normal pager to scroll through the text +(mostly the "more" program). When you get to the end pressing <Enter> will +get you back into Vim. + +A disadvantage is that you can't see the man page and the text you are working +on at the same time. There is a trick to make the man page appear in a Vim +window. First, load the man filetype plugin: > + + :runtime! ftplugin/man.vim + +Put this command in your vimrc file if you intend to do this often. Now you +can use the ":Man" command to open a window on a man page: > + + :Man csh + +You can scroll around and the text is highlighted. This allows you to find +the help you were looking for. Use CTRL-W w to jump to the window with the +text you were working on. + To find a man page in a specific section, put the section number first. +For example, to look in section 3 for "echo": > + + :Man 3 echo + +To jump to another man page, which is in the text with the typical form +"word(1)", press CTRL-] on it. Further ":Man" commands will use the same +window. + +To display a man page for the word under the cursor, use this: > + + \K + +(If you redefined the <Leader>, use it instead of the backslash). +For example, you want to know the return value of "strstr()" while editing +this line: + + if ( strstr (input, "aap") == ) ~ + +Move the cursor to somewhere on "strstr" and type "\K". A window will open +to display the man page for strstr(). + +============================================================================== +*12.7* Trim blanks + +Some people find spaces and tabs at the end of a line useless, wasteful, and +ugly. To remove whitespace at the end of every line, execute the following +command: > + + :%s/\s\+$// + +The line range "%" is used, thus this works on the whole file. The pattern +that the ":substitute" command matches with is "\s\+$". This finds white +space characters (\s), 1 or more of them (\+), before the end-of-line ($). +Later will be explained how you write patterns like this, see |usr_27.txt|. + The "to" part of the substitute command is empty: "//". Thus it replaces +with nothing, effectively deleting the matched white space. + +Another wasteful use of spaces is placing them before a tab. Often these can +be deleted without changing the amount of white space. But not always! +Therefore, you can best do this manually. Use this search command: > + + / + +You cannot see it, but there is a space before a tab in this command. Thus +it's "/<Space><Tab>". Now use "x" to delete the space and check that the +amount of white space doesn't change. You might have to insert a tab if it +does change. Type "n" to find the next match. Repeat this until no more +matches can be found. + +============================================================================== +*12.8* Find where a word is used + +If you are a UNIX user, you can use a combination of Vim and the grep command +to edit all the files that contain a given word. This is extremely useful if +you are working on a program and want to view or edit all the files that +contain a specific variable. + For example, suppose you want to edit all the C program files that contain +the word "frame_counter". To do this you use the command: > + + vim `grep -l frame_counter *.c` + +Let's look at this command in detail. The grep command searches through a set +of files for a given word. Because the -l argument is specified, the command +will only list the files containing the word and not print the matching lines. +The word it is searching for is "frame_counter". Actually, this can be any +regular expression. (Note: What grep uses for regular expressions is not +exactly the same as what Vim uses.) + The entire command is enclosed in backticks (`). This tells the UNIX shell +to run this command and pretend that the results were typed on the command +line. So what happens is that the grep command is run and produces a list of +files, these files are put on the Vim command line. This results in Vim +editing the file list that is the output of grep. You can then use commands +like ":next" and ":first" to browse through the files. + + +FINDING EACH LINE + +The above command only finds the files in which the word is found. You still +have to find the word within the files. + Vim has a built-in command that you can use to search a set of files for a +given string. If you want to find all occurrences of "error_string" in all C +program files, for example, enter the following command: > + + :grep error_string *.c + +This causes Vim to search for the string "error_string" in all the specified +files (*.c). The editor will now open the first file where a match is found +and position the cursor on the first matching line. To go to the next +matching line (no matter in what file it is), use the ":cnext" command. To go +to the previous match, use the ":cprev" command. Use ":clist" to see all the +matches and where they are. + The ":grep" command uses the external commands grep (on Unix) or findstr +(on Windows). You can change this by setting the option 'grepprg'. + +============================================================================== + +Next chapter: |usr_20.txt| Typing command-line commands quickly + +Copyright: see |manual-copyright| vim:tw=78:ts=8:noet:ft=help:norl: |