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Full Discussion: using tail -f
Top Forums Shell Programming and Scripting using tail -f Post 30547 by LivinFree on Wednesday 23rd of October 2002 04:37:50 PM
Old 10-23-2002
Try this:
Code:
(tail -f /var/log/messages & ) | grep -i login

If you let tail run in the backgroundit lets grep work. As tail dumps out to stdout, grep is patiently waiting, reading stdin.

This will just dump out to your screen until you hit something like ctrl+c. If you want something more elaborate, you could sent the tail output to a different fd, and have grep read in from that fd.

Good luck!
 

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LEARN ABOUT X11R4

zgrep

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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