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Full Discussion: Problems understanding pipes
Top Forums Programming Problems understanding pipes Post 302562633 by ab_tall on Friday 7th of October 2011 01:19:26 PM
Old 10-07-2011
@Corona Apologise if the bumping was excessive..
The fork is done as a part of the line, run the command in a subshell.
Thanks for the explanation though, let me ensure if I am correctly closing the ends of the pipe.

EDIT: Followup question though, is it necessary to use different pipes if there are more than 2 commands in my pipe?
Or can i reuse the same pipe?
say if I want to an ls | grep <pattern> | more.
Once ls is done with its task and grep done with the reading, the pipe would no longer be used right? so can the same be used between grep and more? [I think not..as grep would need access to 2 pipes simultaneously...one to read from and other to write to..in that case I need to address the correct file descriptors in my 2D array]
Last edited by ab_tall; 10-07-2011 at 02:25 PM..
 

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LEARN ABOUT PHP

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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