How to compare two numbers

shell-script solaris numeric-data

5,263

Those aren't numbers, at least not in the mathematical sense. What you probably want is version string comparison, provided by GNU (and possibly other) sort --version-sort/sort -V:

if [[ "$(sort --version-sort <<< "$(printf '%s\n' "$val1" "$val2")" | head --lines=1)" = "$val1" ]]
then
    echo "$val1 <= $val2"
fi

5,263

Author by

serenesat

Updated on September 18, 2022

Comments

serenesat almost 2 years
I have following two values:
```
val1=13.2.8
val2=15.0.5
```
I want to check if val1 is less than val2 or not, I tried this:
```
echo "if ($val1<$val2) 1" | bc
```
But it is throwing following error:
```
syntax error on line 1, teletype
```
For normal floating numbers it is working fine.

What is the best way to achieve this?
- Jeff Schaller almost 7 years
  
  Excluding GNU tools, I assume based on the Solaris tag?
sasanj almost 7 years

Why demoting? Those are not real numbers.
smw almost 7 years

I didn't downvote, but I'm guessing it's because lexical comparison will likely give the "wrong" answer for cases like val1=3.2.8, val2=15.0.5
serenesat almost 7 years

I am getting this error : head: illegal option -- lines=1 sort: illegal option -- version-sort usage: sort [-cCmu] [-o output] [-T directory] [-S mem] [-dfiMnr] [-b] [-t char] [-k keydef] [+pos1 [-pos2]] files...
l0b0 almost 7 years

Looks like your version of head and sort have different options. Look at the man pages to find which map to the options I've used.
Lambert almost 7 years

If you have Solaris 11, try gsort. a lot of GNU tools are available nowadays but these are not de default tools.