greycat 1127137515 learn http://wooledge.org/mywiki/ArithmeticExpression savetheWorld 1211896797 forget savetheWorld 1211896800 learn ((a=$a+7)) # Adds 7 to variable a; ((a = a + 7)); # does the same, as does : ((a += 7)) ; see http://wooledge.org/mywiki/ArithmeticExpression for much more lhunath 1211897030 forget lhunath 1211897084 learn Add 7 to a variable: let a+=7; ((a+=7)); a=$((a+7)); See http://wooledge.org/mywiki/ArithmeticExpression llua 1460119726 forget llua 1460119767 learn Add 7 to a variable: ((a+=7)); a=$((a+7)); let a+=7; See http://mywiki.wooledge.org/ArithmeticExpression greycat 1493825301 forget greycat 1493825303 learn Add 7 to a variable: ((a+=7)) OR a=$((a+7)) OR let 'a+=7' # See http://mywiki.wooledge.org/ArithmeticExpression