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Full Discussion: grep'ing a variable - why not working
Top Forums UNIX for Dummies Questions & Answers grep'ing a variable - why not working Post 302577610 by methyl on Tuesday 29th of November 2011 12:42:54 PM
Old 11-29-2011
There is much variation in the output format for "ps -ef" .

Please post what Operating System and version you have, the Shell (e.g. bash, ksh, sh etc.) and a sample of a few relevant lines from:
Code:
ps -ef|egrep "defunct|PID"|grep -v "grep"

The "egrep" for "PID" is just to get the column headings for this example and nothing to do with your variable called $PID.

I can't see anything wrong with the syntax of the first example you posted. Had you used the reserved variable name $PPID that would give trouble in many shells (notably bash).

The way your script behaves makes me wonder if your version of "ps", "awk" or Shell is changing the value of ${PID} (but not when it is a parameter to a sub-shell).

If you are on Solaris use "nawk" not "awk".

What are you actually trying to do?
 

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LEARN ABOUT LINUX

xzgrep

XZGREP(1)							     XZ Utils								 XZGREP(1)

NAME

       xzgrep - search compressed files for a regular expression

SYNOPSIS

       xzgrep [grep_options] [-e] pattern file...
       xzegrep ...
       xzfgrep ...
       lzgrep ...
       lzegrep ...
       lzfgrep ...

DESCRIPTION

       xzgrep  invokes	grep(1)  on  files  which may be either uncompressed or compressed with xz(1), lzma(1), gzip(1), or bzip2(1).  All options
       specified are passed directly to grep(1).

       If no file is specified, then standard input is decompressed if necessary and fed to grep(1).  When reading from  standard  input,  gzip(1)
       and bzip2(1) compressed files are not supported.

       If  xzgrep  is  invoked as xzegrep or xzfgrep then egrep(1) or fgrep(1) is used instead of grep(1).  The same applies to names lzgrep, lze-
       grep, and lzfgrep, which are provided for backward compatibility with LZMA Utils.

ENVIRONMENT

       GREP   If the GREP environment variable is set, xzgrep uses it instead of grep(1), egrep(1), or fgrep(1).

SEE ALSO

       grep(1), xz(1), gzip(1), bzip2(1), zgrep(1)

Tukaani 							    2010-09-27								 XZGREP(1)
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