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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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RESCAN-SCSI-BUS.SH(1)						   User Commands					     RESCAN-SCSI-BUS.SH(1)

NAME
rescan-scsi-bus.sh - script for adding and removing SCSI devices without rebooting SYNOPSIS
rescan-scsi-bus.sh [options] [host [host ...]] OPTIONS
-a, --alltargets scan all targets, not just currently existing [default: disabled] -d enable debug [default: 0] -l activates scanning for LUNs 0--7 [default: 0] -L NUM activates scanning for LUNs 0--NUM [default: 0] -w, --wide scan for target device IDs 0--15 [default: 0--7] -c enables scanning of channels 0 1 [default: 0 / all detected ones] -r, --remove enables removing of devices [default: disabled] -f, --flush flush failed multipath devices [default: disabled] -i, --issue-lip issue a FibreChannel LIP reset [default: disabled] -u, --update look for existing disks that have been remapped -s, --resize look for resized disks and reload associated multipath devices, if applicable --forcerescan rescan existing devices --forceremove remove and readd every device (DANGEROUS) --nooptscan don't stop looking for LUNs is 0 is not found --color use coloured prefixes OLD/NEW/DEL --hosts=LIST scan only host(s) in LIST --channels=LIST scan only channel(s) in LIST --ids=LIST scan only target ID(s) in LIST --luns=LIST scan only lun(s) in LIST --sync, --nosync issue a sync / no sync [default: sync if remove] --attachpq3 tell kernel to attach sg to LUN 0 that reports PQ=3 --reportlun2 tell kernel to try REPORT_LUN even on SCSI2 devices --largelun tell kernel to support LUNs > 7 even on SCSI2 devs --sparselun tell kernel to support sparse LUN numbering Host numbers may thus be specified either directly on cmd line (deprecated) or or with the --hosts=LIST parameter (recommended). LIST: A[-B][,C[-D]]... is a comma separated list of single values and ranges (No spaces allowed.) SEE ALSO
rescan-scsi-bus.sh Homepage: http://www.garloff.de/kurt/linux/#rescan-scsi sg3_utils Homepage: http://sg.danny.cz/sg rescan-scsi-bus.sh 1.57 leden 2014 RESCAN-SCSI-BUS.SH(1)
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