.\" $OpenBSD: ae7,v 1.2 2003/06/26 16:24:16 mickey Exp $ .\" .\" Copyright (C) Caldera International Inc. 2001-2002. .\" 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 and documentation 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 or owned by Caldera .\" International, Inc. .\" 4. Neither the name of Caldera International, Inc. nor the names of other .\" contributors may be used to endorse or promote products derived from .\" this software without specific prior written permission. .\" .\" USE OF THE SOFTWARE PROVIDED FOR UNDER THIS LICENSE BY CALDERA .\" INTERNATIONAL, INC. 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 CALDERA INTERNATIONAL, INC. 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. .\" .\" @(#)ae7 8.1 (Berkeley) 6/8/93 .\" .NH SUPPORTING TOOLS .PP There are several tools and techniques that go along with the editor, all of which are relatively easy once you know how .UL ed works, because they are all based on the editor. In this section we will give some fairly cursory examples of these tools, more to indicate their existence than to provide a complete tutorial. More information on each can be found in [3]. .SH Grep .PP Sometimes you want to find all occurrences of some word or pattern in a set of files, to edit them or perhaps just to verify their presence or absence. It may be possible to edit each file separately and look for the pattern of interest, but if there are many files this can get very tedious, and if the files are really big, it may be impossible because of limits in .UL ed . .PP The program .UL grep was invented to get around these limitations. The search patterns that we have described in the paper are often called `regular expressions', and `grep' stands for .P1 g/re/p .P2 That describes exactly what .UL grep does _ it prints every line in a set of files that contains a particular pattern. Thus .P1 grep \(fmthing\(fm file1 file2 file3 ... .P2 finds `thing' wherever it occurs in any of the files `file1', `file2', etc. .UL grep also indicates the file in which the line was found, so you can later edit it if you like. .PP The pattern represented by `thing' can be any pattern you can use in the editor, since .UL grep and .UL ed use exactly the same mechanism for pattern searching. It is wisest always to enclose the pattern in the single quotes \(fm...\(fm if it contains any non-alphabetic characters, since many such characters also mean something special to the .UX command interpreter (the `shell'). If you don't quote them, the command interpreter will try to interpret them before .UL grep gets a chance. .PP There is also a way to find lines that .ul don't contain a pattern: .P1 grep -v \(fmthing\(fm file1 file2 ... .P2 finds all lines that don't contains `thing'. The .UL \-v must occur in the position shown. Given .UL grep and .UL grep\ \-v , it is possible to do things like selecting all lines that contain some combination of patterns. For example, to get all lines that contain `x' but not `y': .P1 grep x file... | grep -v y .P2 (The notation | is a `pipe', which causes the output of the first command to be used as input to the second command; see [2].) .SH Editing Scripts .PP If a fairly complicated set of editing operations is to be done on a whole set of files, the easiest thing to do is to make up a `script', i.e., a file that contains the operations you want to perform, then apply this script to each file in turn. .PP For example, suppose you want to change every `Unix' to `UNIX' and every `Gcos' to `GCOS' in a large number of files. Then put into the file `script' the lines .P1 g/Unix/s//UNIX/g g/Gcos/s//GCOS/g w q .P2 Now you can say .P1 ed file1