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Operating Systems Linux Fedora Shell Script - awk, begin, for and print Post 302848977 by Corona688 on Friday 30th of August 2013 02:14:31 PM
Old 08-30-2013
The BEGIN section is a section of code awk reads before it reads any files.

It is not running shell code, which is why it looks so different, it's running awk code, it's its own language.

Code:
for (y=yc; y<=yb; y++) { x = a2*y*y+b2*y+c2; print x, y };

If yc=0 and yb=4, it loops 5 times, with y=0, y=1, y=2, y=3, y=4, y=5, following the mathematical formula given to calculate new results for x, then prints the coordinates.
 

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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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