From pa.dec.com!decwrl!sdd.hp.com!samsung!uunet!sparky!kent Tue Jul 16 09:10:23 PDT 1991 Article: 2478 of comp.sources.misc Xref: pa.dec.com comp.sources.misc:2478 comp.lang.perl:5969 Path: pa.dec.com!decwrl!sdd.hp.com!samsung!uunet!sparky!kent From: prechelt@i41s14.ira.uka.de (Lutz Prechelt) Newsgroups: comp.sources.misc,comp.lang.perl Subject: v20i088: cgrep - context grep in perl, Part01/01 Message-ID: <1991Jul3.010431.25463@sparky.IMD.Sterling.COM> Date: 3 Jul 91 01:04:31 GMT Sender: kent@sparky.IMD.Sterling.COM (Kent Landfield) Reply-To: prechelt@i41s14.ira.uka.de (Lutz Prechelt) Organization: University of Karlsruhe, FRG Lines: 242 Approved: kent@sparky.imd.sterling.com X-Md4-Signature: 08347b693b1d098eaac6eb4df1a75ee0 Submitted-by: Lutz Prechelt Posting-number: Volume 20, Issue 88 Archive-name: cgrep/part01 The following is a version of grep (as a Perl script) that gives you a number of context lines along with the matching line. It was inspired by Larry Walls example from the perl book. The context size is selectable. The program has several options; in particular there is an especially useful 'paragraph mode' where the context is broken off at an empty line. For exact usage, see the message in the body of the script. You will probably have to edit the first line of the script, to tell it where your 'perl' resides. Lutz Lutz Prechelt (++49/721/608-4317, FAX: ++49/721/697760) Institut fuer Programmstrukturen und Datenorganisation Universitaet Karlsruhe; D-7500 Karlsruhe 1; Germany prechelt@ira.uka.de or prechelt!ira.uka.de@relay.csnet -------------------------------------------------------------- #! /bin/sh # This is a shell archive. Remove anything before this line, then feed it # into a shell via "sh file" or similar. To overwrite existing files, # type "sh file -c". # The tool that generated this appeared in the comp.sources.unix newsgroup; # send mail to comp-sources-unix@uunet.uu.net if you want that tool. # Contents: cgrep # Wrapped by kent@sparky on Tue Jul 2 19:56:51 1991 PATH=/bin:/usr/bin:/usr/ucb ; export PATH echo If this archive is complete, you will see the following message: echo ' "shar: End of archive."' if test -f 'cgrep' -a "${1}" != "-c" ; then echo shar: Will not clobber existing file \"'cgrep'\" else echo shar: Extracting \"'cgrep'\" \(4771 characters\) sed "s/^X//" >'cgrep' <<'END_OF_FILE' X#!/bin/perl X# X# Copyright (C) 1991 by Lutz Prechelt, Karlsruhe X# X# This program is free software; you can redistribute it and/or modify X# it under the terms of the GNU General Public License as published by X# the Free Software Foundation; either version 1, or (at your option) X# any later version. X# This program is distributed in the hope that it will be useful, X# but WITHOUT ANY WARRANTY; without even the implied warranty of X# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the X# GNU General Public License for more details. X# If you don't have a copy of the GNU General Public License write to X# Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. X X# Author: Lutz Prechelt (prechelt@ira.uka.de), X# 23.03.91 X# Change: Lutz Prechelt, 02.07.91 X# X# Usage: see message at "die" below. X X$infinity = 10000; X X$precontext = 2; X$postcontext = 2; X$paragraphmode = 0; X$withlinenumber = 0; X$withfilename = 0; X$wrong_option = 0; X$reversemode = 0; X$delimiterstring = "-----------\n"; X# $endpara = '\S.*\n'; X Xsub showline { X if ($withfilename != 0) { X printf ("\"%s\"", $ARGV); X } X if ($withfilename != 0 && $withlinenumber != 0) { X print ","; X } X if ($withlinenumber != 0) { X printf ("%4d", $.); X } X if ($withfilename != 0 || $withlinenumber != 0) { X print ": "; X } X print ($_[0]); X} X X X# Process the Options: Xdo { X $something_done = 1; X if ($ARGV[0] =~ /^-(\d+)$/) { X $precontext = $postcontext = $1; X shift; X } X elsif ($ARGV[0] =~ /^-(\d+)[\,\+\/\;](\d+)$/) { X $precontext = $1; X $postcontext = $2; X shift; X } X elsif ($ARGV[0] =~ /^-d$/ && $#ARGV > 0) { X $delimiterstring = $ARGV[1]; X $delimiterstring =~ s/\\n/\n/o; X shift; shift; X } X elsif ($ARGV[0] =~ /^-d(.*)$/) { X $delimiterstring = $1; X $delimiterstring =~ s/\\n/\n/o; X shift; X } X elsif ($ARGV[0] =~ /^-p$/) { X $paragraphmode = 1; X shift; X } X elsif ($ARGV[0] =~ /^-n$/) { X $withlinenumber = 1; X shift; X } X elsif ($ARGV[0] =~ /^-h$/) { X $withfilename = 1; X shift; X } X elsif ($ARGV[0] =~ /^-v$/) { X $reversemode = 1; X shift; X } X elsif ($ARGV[0] =~ /^-e$/) { # end options (for expressions starting with - ) X $something_done = 0; X shift; X } X elsif ($ARGV[0] =~ /^-/) { X printf ("don't know option '%s'\n", $ARGV[0]); X $wrong_option = 1; X $something_done = 0; X shift; X } X else { X $something_done = 0; X } X} while ($something_done); X X X# Usage message: Xif ($#ARGV == -1 || $wrong_option) { X die " X Usage: cgrep [-pre[,post]] [-p] [-v] [-h] [-n] [-d string] pattern X[file...] X X cgrep is a context grep. It displays more than the one matching line for X every match (2 before and 2 after as default). X X -3 means display 3 lines before and 3 lines after the match X -5,12 means display 5 lines before the match and 12 lines after X -p means display only as much of the context as belongs to the X current paragraph. (paragraphs bounded by empty lines) X -v means invert search (display nomatches) X -h means toggle display filename before every line X -n means display line number before every line X -d string means use string as the output delimiter string X pattern is a Perl regular expression (you better quote it !) XExiting"; X} X X Xif (length (@ARGV) > 1) { X $withfilename = !$withfilename; X} X X X# Get the pattern and protect the delimiter. X$pat = shift; X$pat =~ s#/#\\/#g; X X X# current line will always be at end of array, i.e. $ary[$currentpre] X$_ = <>; Xpush(@ary,$_); X$currentpre = 0; X X X# now use @ary as a silo, shifting and pushing. X# the length of the @ary at any time is $currentpre + 1 X# the current line is @ary[$currentpre], the postcontext is not held in @ary. X$seq = 0; X$lastoutput = $infinity; #last output is infinitely many lines ago X$cur = @ary[0]; #current line Xwhile ($cur) { #as long as there is something to look at X if ($reversemode == 1 ? $cur !~ /$pat/o : $cur =~ /$pat/o) { #match found X if ($lastoutput <= $postcontext) { X &showline ($cur); X } X else { X print $delimiterstring if ($seq++ && $precontext + $postcontext > 0); X foreach $line (@ary) { X &showline ($line); X } X } X $lastoutput = 0; X } X elsif (($cur !~ /\S.*\n/o && $paragraphmode == 1) || eof) { X#paragraph/file end X for (; $currentpre >= 0; $currentpre--) { X shift (@ary); X } X $lastoutput = $infinity; X close (ARGV) if (eof); X } X elsif ($lastoutput <= $postcontext) { #another line of postcontext X &showline ($cur); X } X #goto next line of input: X $lastoutput++; X $_ = <> if $_; X push(@ary,$_); X if ($currentpre < $precontext) { X $currentpre++; X } X else { X shift(@ary); X } X $cur = $ary[$currentpre]; X} X X X END_OF_FILE if test 4771 -ne `wc -c <'cgrep'`; then echo shar: \"'cgrep'\" unpacked with wrong size! fi chmod +x 'cgrep' # end of 'cgrep' fi echo shar: End of archive. exit 0 exit 0 # Just in case... -- Kent Landfield INTERNET: kent@sparky.IMD.Sterling.COM Sterling Software, IMD UUCP: uunet!sparky!kent Phone: (402) 291-8300 FAX: (402) 291-4362 Please send comp.sources.misc-related mail to kent@uunet.uu.net.