set +o posix declare -i iv jv iv=$(( 3 + 5 * 32 )) echo $iv iv=iv+3 echo $iv iv=2 jv=iv let "jv *= 2" echo $jv jv=$(( $jv << 2 )) echo $jv let jv="$jv / 2" echo $jv jv="jv >> 2" echo $jv iv=$((iv+ $jv)) echo $iv echo $((iv -= jv)) echo $iv echo $(( iv == jv )) echo $(( iv != $jv )) echo $(( iv < jv )) echo $(( $iv > $jv )) echo $(( iv <= $jv )) echo $(( $iv >= jv )) echo $jv echo $(( ~$jv )) echo $(( ~1 )) echo $(( ! 0 )) echo $(( jv % 2 )) echo $(( $iv % 4 )) echo $(( iv <<= 16 )) echo $(( iv %= 33 )) echo $(( 33 & 55 )) echo $(( 33 | 17 )) echo $(( iv && $jv )) echo $(( $iv || jv )) echo $(( iv && 0 )) echo $(( iv & 0 )) echo $(( iv && 1 )) echo $(( iv & 1 )) echo $(( $jv || 0 )) echo $(( jv | 0 )) echo $(( jv | 1 )) echo $(( $jv || 1 )) let 'iv *= jv' echo $iv echo $jv let "jv += $iv" echo $jv echo $(( jv /= iv )) echo $(( jv <<= 8 )) echo $(( jv >>= 4 )) echo $(( iv |= 4 )) echo $(( iv &= 4 )) echo $(( iv += (jv + 9))) echo $(( (iv + 4) % 7 )) # unary plus, minus echo $(( +4 - 8 )) echo $(( -4 + 8 )) # conditional expressions echo $(( 4<5 ? 1 : 32)) echo $(( 4>5 ? 1 : 32)) echo $(( 4>(2+3) ? 1 : 32)) echo $(( 4<(2+3) ? 1 : 32)) echo $(( (2+2)<(2+3) ? 1 : 32)) echo $(( (2+2)>(2+3) ? 1 : 32)) # check that the unevaluated part of the ternary operator does not do # evaluation or assignment x=i+=2 y=j+=2 declare -i i=1 j=1 echo $((1 ? 20 : (x+=2))) echo $i,$x echo $((0 ? (y+=2) : 30)) echo $j,$y x=i+=2 y=j+=2 declare -i i=1 j=1 echo $((1 ? 20 : (x+=2))) echo $i,$x echo $((0 ? (y+=2) : 30)) echo $i,$y # check precedence of assignment vs. conditional operator # should be an error declare -i x=2 y=$((1 ? 20 : x+=2)) # check precedence of assignment vs. conditional operator declare -i x=2 echo $((0 ? x+=2 : 20)) # associativity of assignment-operator operator declare -i i=1 j=2 k=3 echo $((i += j += k)) echo $i,$j,$k # octal, hex echo $(( 0x100 | 007 )) echo $(( 0xff )) echo $(( 16#ff )) echo $(( 16#FF/2 )) echo $(( 8#44 )) echo $(( 8 ^ 32 )) # other bases echo $(( 16#a )) echo $(( 32#a )) echo $(( 56#a )) echo $(( 64#a )) echo $(( 16#A )) echo $(( 32#A )) echo $(( 56#A )) echo $(( 64#A )) echo $(( 64#_ )) echo $(( 64#@ )) # weird bases echo $(( 3425#56 )) # missing number after base echo $(( 2# )) # these should generate errors echo $(( 7 = 43 )) echo $(( 2#44 )) echo $(( 44 / 0 )) let 'jv += $iv' echo $(( jv += \$iv )) let 'rv = 7 + (43 * 6' # more errors declare -i i i=0#4 i=2#110#11 ((echo abc; echo def;); echo ghi) if (((4+4) + (4 + 7))); then echo ok fi (()) # make sure the null expression works OK a=(0 2 4 6) echo $(( a[1] + a[2] )) echo $(( (a[1] + a[2]) == a[3] )) (( (a[1] + a[2]) == a[3] )) ; echo $? # test pushing and popping the expression stack unset A A="4 + " echo $(( ( 4 + A ) + 4 )) A="3 + 5" echo $(( ( 4 + A ) + 4 )) # badly-formed conditional expressions echo $(( 4 ? : $A )) echo $(( 1 ? 20 )) echo $(( 4 ? 20 : )) # precedence and short-circuit evaluation B=9 echo $B echo $(( 0 && B=42 )) echo $B echo $(( 1 || B=88 )) echo $B echo $(( 0 && (B=42) )) echo $B echo $(( (${$} - $$) && (B=42) )) echo $B echo $(( 1 || (B=88) )) echo $B # until command with (( )) command x=7 echo $x until (( x == 4 )) do echo $x x=4 done echo $x # exponentiation echo $(( 2**15 - 1)) echo $(( 2**(16-1))) echo $(( 2**16*2 )) echo $(( 2**31-1)) echo $(( 2**0 )) # {pre,post}-{inc,dec}rement and associated errors x=4 echo $x echo $(( x++ )) echo $x echo $(( x-- )) echo $x echo $(( --x )) echo $x echo $(( ++x )) echo $x echo $(( ++7 )) echo $(( 7-- )) echo $(( --x=7 )) echo $(( ++x=7 )) echo $(( x++=7 )) echo $(( x--=7 )) echo $x echo $(( +7 )) echo $(( -7 )) echo $(( ++7 )) echo $(( --7 )) x=4 y=7 (( x=8 , y=12 )) echo $x $y # should be an error (( x=9 y=41 )) # These are errors echo $((a b)) ((a b)) n=42 printf "%d\n" $n printf "%i\n" $n echo $(( 8#$(printf "%o\n" $n) )) printf "%u\n" $n echo $(( 16#$(printf "%x\n" $n) )) echo $(( 16#$(printf "%X\n" $n) ))