X=87;
if [ $X -gt 100 ]; then
# do something if contrition is true
elif [ $X -lt 200 ]; then
# do something if second condition is also true
else
# do something if all conditions are false
fi
Conditions
x -eq y True if the integers x and y are algebraically equal
x -ne y True if the integers x and y are not algebraically equal
x -gt y True if the integer x is algebraically greater than the integer y
x -ge y True if the integer x is algebraically greater than or equal to the integer y
x -lt y True if the integer x is algebraically less than the integer y
x -le y True if the integer x is algebraically less than or equal to the integer y
s1 True if s1 is not the null string
s1 = s2 True if strings s1 and s2 are identical
s1 != s2 True if strings s1 and s2 are not identical
# AND: test if X is between 100 and 200
if [ $X -gt 100 ] && [ $X -lt 200 ]; then
echo "X is between 100 and 200";
fi
# OR: test if X is equal to 100 or equal to 200
if [ $X -eq 100 ] || [ $X -eq 200 ]; then
echo "X is exact 100 or exact 200";
fi
if condition ; then
commands
fi
if condition ; then
commands
else
commands
fi
if condition1 ; then
commands
elif condition2 ; then
commands
else
commands
fi