Grouping commands of if...then statement, including assignation of variable for shell/bash in a single line

I know the existence of *while-do-done *. Alternatively, I know that I can use *for-do-done *. But, I was trying to test manually using *if-then-else*. I would to like to execute a command, but doing a shift with addition in each iteration. sh-3.2# currPos=0;stepSize=16; sh-3.2# hexdump -n $stepSize -Cv /dev/disk0s1 -s $currPos;currPos=$(($currPos + $stepSize));echo $currPos; 00000000 8d 1c 09 48 65 8c 3c 6e 01 00 00 00 00 00 00 00 |...He.offset (-s) is not taking the updated value of variable $currPos. But in the echo command the $currPos variable is changing (16, 32 and 48)! **EDIT 1**: According to *Kusalananda* (Thanks a lot!) I fix the first step. sh-3.2# currPos=0;stepSize=16;finalStep=48; sh-3.2# hexdump -n $stepSize -Cv -s $currPos /dev/disk0s1;currPos=$(($currPos + $stepSize));echo $currPos; 00000000 8d 1c 09 48 65 8c 3c 6e 01 00 00 00 00 00 00 00 |...He.https://linuxize.com/post/bash-if-else-statement/ something of: if, then, else, fi and (-eq, -gt, -ge, -lt, -le, !=) and break. Trying to use a iterative with if, break: sh-3.2# currPos=0;stepSize=16;finalStep=48; sh-3.2# if [ $currPos -le $finalStep ]; then (hexdump -n $stepSize -Cv /dev/disk0s1 -s $currPos;currPos=$(($currPos + $stepSize));echo $currPos;); else break; fi 00000000 8d 1c 09 48 65 8c 3c 6e 01 00 00 00 00 00 00 00 |...He.Note**: I'm grouping inside of ( and ) the commands (hexdump, assignation and echo) of the then of the if statement. But, in this case, the echo is working worst the first case (the value of $currPos variable is not changed). According to this article I need to use { and }. But I get: sh-3.2# if [ $currPos -le $finalStep ]; then {hexdump -n $stepSize -Cv -s $currPos /dev/disk0s1;currPos=$(($currPos + $stepSize));echo $currPos;}; else break; fi sh: syntax error near unexpected token `}' **How I can do that?, How solve this (the update value of variable is not taken)?** **EDIT 2** *Stéphane-Chazelas* Helped me! (read comments about { and }, note the space after of { and before of } respectively). sh-3.2# currPos=0;stepSize=16;finalStep=48; sh-3.2# if [ $currPos -le $finalStep ]; then { hexdump -n $stepSize -Cv -s $currPos /dev/disk0s1;currPos=$(($currPos + $stepSize));echo $currPos; }; else break; fi 00000000 8d 1c 09 48 65 8c 3c 6e 01 00 00 00 00 00 00 00 |...He.else break): sh-3.2# if [ $currPos -le $finalStep ]; then { hexdump -n $stepSize -Cv -s $currPos /dev/disk0s1;currPos=$(($currPos + $stepSize));echo $currPos }; else break; fi sh: syntax error near unexpected token `else' sh-3.2# if [ $currPos -le $finalStep ]; then { hexdump -n $stepSize -Cv -s $currPos /dev/disk0s1;currPos=$(($currPos + $stepSize));echo $currPos; }; else break; fi sh-3.2# if [ $currPos -le $finalStep ]; then { hexdump -n $stepSize -Cv -s $currPos /dev/disk0s1;currPos=$(($currPos + $stepSize));echo $currPos; } else break; fi sh-3.2#