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Full Discussion: grep backreferencing question
Top Forums Shell Programming and Scripting grep backreferencing question Post 302464248 by prasanna1157 on Tuesday 19th of October 2010 03:01:23 PM
Old 10-19-2010
Thanks.

---------- Post updated at 02:59 PM ---------- Previous update was at 02:56 PM ----------
Quote:
Originally Posted by Scrutinizer
That wasn't part of your problem statement, was it? Anyway,
Code:
grep -E 'int .*([^,]+),.*\1[,\;]|int .*,[,\;]' infile

Code:
grep 'int .*\([^,][^,]*\),.*\1[,\;]\|int .*,[,\;]' infile

Oh, sorry. Yes, I did not state it initially.

One more question, the .* makes it match anything. But can I match only valid declarations? That is, the variables should start with alpha, can have only alphabets and numbers. Let's assume lowercase only. How do you tweak the above to check for that?

Thanks a lot.

---------- Post updated at 03:01 PM ---------- Previous update was at 02:59 PM ----------
Quote:
Originally Posted by DGPickett
Well, C legality is a whole lot more than a grep! Is cc or CC making it hard to decipher?

I recommend never declaring more than 1 variable on a line. It facilitates diff and diff3 use. It gives you a distinct line number for every variable in error.
Thanks.
So, can we not check for illegal declarations using the regex?
 

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LEARN ABOUT LINUX

zegrep

ZGREP(1)                                                      General Commands Manual                                                     ZGREP(1)

NAME

       zgrep - search possibly compressed files for a regular expression

SYNOPSIS

       zgrep [ grep_options ] [ -e ] pattern filename...

DESCRIPTION

       Zgrep  invokes  grep  on  compressed  or  gzipped  files.   These  grep  options  will  cause  zgrep  to  terminate  with  an  error  code:
       (-[drRzZ]|--di*|--exc*|--inc*|--rec*|--nu*).  All other options specified are passed directly to grep.  If no file is specified,  then  the
       standard input is decompressed if necessary and fed to grep.  Otherwise the given files are uncompressed if necessary and fed to grep.

       If the GREP environment variable is set, zgrep uses it as the grep program to be invoked.

EXIT CODE

       2 - An option that is not supported was specified.

AUTHOR

       Charles Levert (charles@comm.polymtl.ca)

SEE ALSO

       grep(1), gzexe(1), gzip(1), zdiff(1), zforce(1), zmore(1), znew(1)

                                                                                                                                          ZGREP(1)
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