Numbers and Arithmetic in bash: Difference between revisions
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<syntaxhighlight lang='bash'> | <syntaxhighlight lang='bash'> | ||
a=1 | |||
b=2 | |||
if [[ $(eval ${a} - ${b}) < 0 ]]; then | if [[ $(eval ${a} - ${b}) < 0 ]]; then | ||
... | ... |
Revision as of 04:31, 11 December 2019
Internal
How to Tell if a Variable has an Integer Value
v=10 if expr ${v} + 1 >/dev/null 2>&1; then # # the value contained by v is an integer # else # # the value contained by v is NOT an integer # fi
More about
Floating Point Operations
Multiplication:
local operand1=10.1 local operand2=20.2 result=$(echo ${operand1} ${operand2} | awk '{printf "%5.1f\n",$1*$2}') || exit 1
Division:
local operand1=10.1 local operand2=20.2 result=$(echo ${operand1} ${operand2} | awk '{printf "%5.1f\n",$1/$2}') || exit 1
Increment an Integer
local i=0 ((i++))
Decrement an Integer
local i=1
((i--))
Numeric Evaluation in a Condition
a=1
b=2
if [[ $(eval ${a} - ${b}) < 0 ]]; then
...
fi