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Top Forums Shell Programming and Scripting Generating a POSIX random number? Post 302977387 by RudiC on Sunday 17th of July 2016 07:32:55 AM
Old 07-17-2016
Twothree comments:
  • the while(1) inside the awk script will make it generate random numbers until hell freezes, is that needed at all to fill byteone and bytetwo?
  • Piping into a while loop executing in a subshell will not make the variables available in the parent shell. If you want to use those, a different mechanism is needed.
  • In some awks, calling srand() is pointless as it preseeds the random generator from the system clock which is done anyway when that awk starts.

So, although some people in these fora rant about one liners - just kidding - you might want to consider this:

Code:
TMP=$(awk ' BEGIN {printf( "%d %d\n", 16 * rand(), 16 * rand() )}')
byteone=${TMP% *}; bytetwo=${TMP#* }


Last edited by RudiC; 07-17-2016 at 09:35 AM..
 

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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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