Java™ Application Development on Linux - Dator

2.2 Eye to Eye with vi41• :7,.w! filename writes lines from line 7 up to and including the currentline to the named file, clobbering any previous contents (think of the “!”as meaning “and don’t argue with me!”).• :q quits, provided you’ve saved your changes (e.g., with :w).• :q! quits without saving any changes to the file.• :n doesn’t exit vi, but moves on to the next file if you started up withmore than one file to edit (e.g., vi Fir.java Pine.java). When you’vereached the last file in the list, you need to quit—for example, with :q.2.2.2 Search and ReplaceWe’ve mentioned searching for a string with / or ?, but what about replacing?Once you’ve located a string with /, you can use cw or C or R or other suchcommands to effect the change. Search for the next occurrence with n, and thenyou can repeat your change (the last c, s, r, and so on) by typing the period“.” that will repeat that last substitution, insert, and so on.But what if you want to make 225 substitutions? Typing n.n.n.n.n.n.would get old after a while. Here, the ex mode, like any good command line,comes to the rescue to help with repetitive tasks.If we want to search and replace all occurrences of one string for another,we can use the command:1,$s/one string/another/Almost all ex commands take an address range, that is, the lines of the fileover which they will operate. If just one line number is given, the commandwill operate on that one line. Two numbers, separated by commas, representthe start and end lines—inclusive—of the operation. The first line is line 1, soa 0 as line number would mean “before the first line.” The line where the cursoris currently located is just “.” (a period). The last line of the file can be representedby the dollar sign ($). You can even do some simple math on theaddresses—for example, .+2 meaning the second line in front of the cursor’scurrent line.TIPThere is a shortcut for the 1,$ address range. Use % to mean “all lines”—forexample, %s/one string/another/.