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Top Forums Shell Programming and Scripting reading alternate lines of a file Post 302443500 by vidyaj on Monday 9th of August 2010 04:45:30 AM
Old 08-09-2010
explanation to answer

hello
could you please explain this command?

Code:
awk '(NR%4==1 || NR%4==0) && $0'


Last edited by Scott; 08-09-2010 at 06:22 AM.. Reason: Code tags, please...
 

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SHTOOL-PATH.TMP(1)					      GNU Portable Shell Tool						SHTOOL-PATH.TMP(1)

NAME
shtool-path - GNU shtool command dealing with shell path variables SYNOPSIS
shtool path [-s|--suppress] [-r|--reverse] [-d|--dirname] [-b|--basename] [-m|--magic] [-p|--path path] str [str ...] DESCRIPTION
This command deals with shell $PATH variables. It can find a program through one or more filenames given by one or more str arguments. It prints the absolute filesystem path to the program displayed on "stdout" plus an exit code of 0 if it was really found. OPTIONS
The following command line options are available. -s, --suppress Supress output. Useful to only test whether a program exists with the help of the return code. -r, --reverse Transform a forward path to a subdirectory into a reverse path. -d, --dirname Output the directory name of str. -b, --basename Output the base name of str. -m, --magic Enable advanced magic search for ""perl"" and ""cpp"". -p, --path path Search in path. Default is to search in $PATH. EXAMPLE
# shell script awk=`shtool path -p "${PATH}:." gawk nawk awk` perl=`shtool path -m perl` cpp=`shtool path -m cpp` revpath=`shtool path -r path/to/subdir` HISTORY
The GNU shtool path command was originally written by Ralf S. Engelschall <rse@engelschall.com> in 1998 for Apache. It was later taken over into GNU shtool. SEE ALSO
shtool(1), which(1). 18-Jul-2008 shtool 2.0.8 SHTOOL-PATH.TMP(1)
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