On Tue, Apr 07, 1998 at 12:55:48AM -0700, George Bonser wrote: > On Tue, 7 Apr 1998, George Bonser wrote: > > > Hehe, try grep! > > > > grep -vFf file2 file1 > > > > should do it. > > For newbies: > > The original poster wants to filter file1 using file2. The output should > contain everything in the input that is NOT matched by the pattern. That > means we are going to need a v option to grep. Now, the pattern is a list > of items separated by newlines so we are going to need to tell grep this > with the F option. Finally, the pattern is contained in a file. We tell > grep the name of that file with the f option followed immediately with the > filename so: > > grep -vFf <pattern-file> <input file> > > means: > > tell me everything that DOES NOT match what is in the newline delimited > file <pattern-file> contained in <input-file> > > > > George Bonser > Just be thankful that Open Group does not own Linux. > http://www.debian.org > Debian/GNU Linux ... the maintainable operating system. >
This will also delete every line that just match partially such as alpha2 or hello-alpha. The correction will be to edited the pattern-file a little through sed before submit it to grep: sed -e 's/^/^/' -e 's/$/$/' <pattern-file> | grep -vf - <input file> ^ and $ stand for 'match begin/end of line' respectively. The sed part (sed -e 's/^/^/' -e 's/$/$' <pattern-file>) say "replace the beginning of each line with '^' and replace the end of line with '$'". They are then send to grep throughout the -f - (- are often used to mean take file from standard input) and then apply to each line of <input file>. Note that I removed the -F to let the default extend expression applied. (The extended grep understand '^' and '$' meaning, but the fast(-F) grep dont). Note also that the reverse (finding all lines in file1 that match those in file2) are easier to acheive through the join utility. Litteraly is 'join file1 file2'. -- ------------------------------------------------------------------------ Fabien Ninoles Running Debian/GNU Linux E-mail: [EMAIL PROTECTED] WebPage: http://www.callisto.si.usherb.ca/~94246757 WorkStation [available when connected!]: http://nightbird.tzone.org/ RSA PGP KEY [E3723845]: 1C C1 4F A6 EE E5 4D 99 4F 80 2D 2D 1F 85 C1 70 ------------------------------------------------------------------------
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