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Full Discussion: awk Array matching and replacing from master file.
Top Forums Shell Programming and Scripting awk Array matching and replacing from master file. Post 302913207 by Corona688 on Thursday 14th of August 2014 01:01:35 PM
Old 08-14-2014
I still see the same problem I saw in your old thread, but with complete input can articulate it better. You will end up with g g g g g g g, not a b c d e f g, because the lines aren't unique -- you can't tell those a's apart. If there happen to be a's you don't want to change, they will all become g anyway.

To do this reliably you need something like diff's output, it actually tells you which line numbers need to change.

Code:
$ diff OLDFILE NEWFILE
$ diff OLDFILE NEWFILE
2,5c2,5
<  a
<  a
<  a
<  a
---
>  b
>  c
>  d
>  e
7a8,10
>  1
>  2
>  3
12,14d14
<  1
<  2
<  3

$

In fact if you could convince whatever's giving you this output to use diff, you could pretty much forget about this problem. diff generates and applies(via patch) text changes reliably and efficiently. That's what it's there for.

Code:
$ diff OLDFILE NEWFILE > new.patch # Save differences between two files

$ patch OLDFILE new.patch # Edit OLDFILE given the differences listed in new.patch

$ diff OLDFILE NEWFILE

$ echo $? # If they are perfectly identical, diff will return 0

0

$

Yes, I know, editing OLDFILE isn't what you want to do, I'm just showing how you could use diff to replace your ad-hoc editing system. I don't see any reliable way to edit MASTERFILE with the input you have unless you can absolutely guarantee the lines in all three files are all completely, 100% unique. This will be extremely dangerous otherwise.
Last edited by Corona688; 08-14-2014 at 02:20 PM..
 

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LEARN ABOUT LINUX

gendiff

GENDIFF(1)						      General Commands Manual							GENDIFF(1)

NAME

       gendiff - utility to aid in error-free diff file generation

SYNOPSIS

       gendiff <directory> <diff-extension>

DESCRIPTION

       gendiff	is  a  rather  simple script which aids in generating a diff file from a single directory.  It takes a directory name and a "diff-
       extension" as its only arguments.  The diff extension should be a unique sequence of characters added to the end of all	original,  unmodi-
       fied files.  The output of the program is a diff file which may be applied with the patch program to recreate the changes.

       The  usual  sequence  of events for creating a diff is to create two identical directories, make changes in one directory, and then use the
       diff utility to create a list of differences between the two.  Using gendiff eliminates the need for the  extra,  original  and	unmodified
       directory copy.	Instead, only the individual files that are modified need to be saved.

       Before editing a file, copy the file, appending the extension you have chosen to the filename.  I.e. if you were going to edit somefile.cpp
       and have chosen the extension "fix", copy it to somefile.cpp.fix before editing it.  Then edit the first copy (somefile.cpp).

       After editing all the files you need to edit in this fashion, enter the directory one level above where your source code resides, and  then
       type

	   $ gendiff somedirectory .fix > mydiff-fix.patch

       You should redirect the output to a file (as illustrated) unless you want to see the results on stdout.

SEE ALSO

       diff(1), patch(1)

AUTHOR

       Marc Ewing <marc@redhat.com>

4th Berkeley Distribution					  Mon Jan 10 2000							GENDIFF(1)
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