Comparing PHP version numbers using Bash?

Question

I have this script that should make sure that the users current PHP version is between a certain range, though it SHOULD work, there is a bug somewhere that makes it think t

Answer 1

Here's another solution that:

• does not run any external command apart from tr
• has no restriction on number of parts in version string
• can compare version strings with different number of parts

Note that it's Bash code using array variables.

compare_versions()
{
    local v1=( $(echo "$1" | tr '.' ' ') )
    local v2=( $(echo "$2" | tr '.' ' ') )
    local len="$(max "${#v1[*]}" "${#v2[*]}")"
    for ((i=0; i<len; i++))
    do
        [ "${v1[i]:-0}" -gt "${v2[i]:-0}" ] && return 1
        [ "${v1[i]:-0}" -lt "${v2[i]:-0}" ] && return 2
    done
    return 0
}

The function returns:

• 0 if versions are equal (btw: 1.2 == 1.2.0)
• 1 if the 1st version is bigger / newer
• 2 if the 2nd version is bigger / newer

However #1 -- it requires one additional function (but function min is quite usable to have anyway):

min()
{
    local m="$1"
    for n in "$@"
    do
        [ "$n" -lt "$m" ] && m="$n"
    done
    echo "$m"
}

However #2 -- it cannot compare version strings with alpha-numeric parts (though that would not be difficult to add, actually).

Answer 2

If you're on Bash 3 with an older version of sort (lookin at you macOS...), then I created the following helper script you can source in (can also be ran as a command):

https://github.com/unicorn-fail/version_compare

Answer 3

A much safer option for testing the PHP CLI version is to use PHP's own version_compare function.

#!/bin/bash

MIN_VERSION="7.0.0"
MAX_VERSION="7.1.4"
PHP_VERSION=`php -r 'echo PHP_VERSION;'`

function version_compare() {
    COMPARE_OP=$1;
    TEST_VERSION=$2;
    RESULT=$(php -r 'echo version_compare(PHP_VERSION, "'${TEST_VERSION}'", "'${COMPARE_OP}'") ? "TRUE" : "";')

    test -n "${RESULT}";
}

if ( version_compare "<" "${MIN_VERSION}" || version_compare ">" "${MAX_VERSION}" ); then
    echo "PHP Version ${PHP_VERSION} must be between ${MIN_VERSION} - ${MAX_VERSION}";
    exit 1;
fi

echo "PHP Version ${PHP_VERSION} is good!";

Answer 4

v_min="5.2.15"
v_max="5.3.15"
v_php="$(php -v | head -1 | awk '{print $2}')"

[ ! "$v_php" = "$(echo -e "$v_php\n$v_min\n$v_max" | sort -V | head -2 | tail -1)" ] && {
  echo "PHP Version $v_php must be between $v_min - $v_max"
  exit
}

This puts v_min, v_max and v_php in version order and tests if v_php is not in the middle.