Thank you :-)~MIKE~(-: On Mon, Mar 2, 2015 at 7:27 PM, Bryan O'Neal < Bryan.ONeal@theonealandassociates.com> wrote: > You can also use let, which may make more sense > let "myVar=$myVar+1" > As for floating point you need something like bc to handle that > myVar=5.4 > myOtherVar=3.1 > myVar=$(echo "scale=2; ($myVar + 3.14) / $myOtherVar" | bc) > echo $myVar > If ran the above would print 2.75 > > On Mon, Mar 2, 2015 at 7:15 PM, der.hans wrote: > >> Am 02. Mär, 2015 schwätzte Michael Havens so: >> >> moin moin Mike, >> >> see the Arithmetic Expansion portion of the bash man page for details. >> >> $((expression)) >> >> That says to evaluate the expression and substitute the result. Remember >> that the shell only does interger math, no decimals. >> >> :) ~$ echo $(( 4 / 2 )) >> 2 >> :) ~$ echo $(( 4 / 3 )) >> 1 >> :) ~$ echo $(( 4 * 3 )) >> 12 >> :) ~$ >> >> Note that you don't need to escape the * when using arithmetic expansion >> because the $(( )) is already quoting. >> >> ciao, >> >> der.hans >> >> >> just starting with this so please, bear with me.... >>> >>> Anyways I am looking at this beginner's script: >>> >>> #! /bin/bash >>> myvar=0 >>> while [ $myvar -ne 20 ] >>> do >>> echo $myvar >>> myvar=$(( $myvar + 1 )) >>> done >>> >>> Now my mind can wrap itself around everything in this script except for >>> tis >>> line: >>> >>> myvar=$(( $myvar + 1 )) >>> >>> Where my difficulty arises is why the '$' before the '(('? >>> (it was geast fun running that script with a minus sign instead!) >>> :-)~MIKE~(-: >>> >>> >> -- >> # http://www.LuftHans.com/ http://www.PhxLinux.org/ >> # "The first requisite of a good citizen in this republic of ours is that >> # he should be able and willing to pull his weight." -- Theodore >> Roosevelt >> --------------------------------------------------- >> PLUG-discuss mailing list - PLUG-discuss@lists.phxlinux.org >> To subscribe, unsubscribe, or to change your mail settings: >> http://lists.phxlinux.org/mailman/listinfo/plug-discuss >> > > > --------------------------------------------------- > PLUG-discuss mailing list - PLUG-discuss@lists.phxlinux.org > To subscribe, unsubscribe, or to change your mail settings: > http://lists.phxlinux.org/mailman/listinfo/plug-discuss >