这里一个有用的技巧是字符串索引。

$ echo "${BASH_VERSION}"
4.4.23(1)-release

$ echo "${BASH_VERSION:0:1}"
4

你们都给出了复杂的解决方案。这里有一个更简单的例子。

function compare_versions {
    local a=${1%%.*} b=${2%%.*}
    [[ "10#${a:-0}" -gt "10#${b:-0}" ]] && return 1
    [[ "10#${a:-0}" -lt "10#${b:-0}" ]] && return 2
    a=${1:${#a} + 1} b=${2:${#b} + 1}
    [[ -z $a && -z $b ]] || compare_versions "$a" "$b"
}

用法:compare_versions <ver_a> <ver_b>

返回代码1表示第一个版本大于第二个版本，2表示小于第二个版本，0表示两者相等。

也是一个非递归的版本:

function compare_versions {
    local a=$1 b=$2 x y

    while [[ $a || $b ]]; do
        x=${a%%.*} y=${b%%.*}
        [[ "10#${x:-0}" -gt "10#${y:-0}" ]] && return 1
        [[ "10#${x:-0}" -lt "10#${y:-0}" ]] && return 2
        a=${a:${#x} + 1} b=${b:${#y} + 1}
    done

    return 0
}

我希望这对某些人有用(使用awk)

  #!/bin/bash

  available_version=1.2.3 # or online version
  this_version=1.2.1

  if [[ "ok" == "$(echo | awk "(${available_version} > ${this_version}) { print \"ok\"; }")" ]]; then
    echo "Notice, new version is available"
  elif [[ "ok" == "$(echo | awk "(${available_version} == ${this_version}) { print \"ok\"; }")" ]]; then
    echo "OK, version is up to date"
  else
    echo "Warning, the current version is ahead of the online version!"
  fi

您可以通过版本命令行查看版本约束

$ version ">=1.0, <2.0" "1.7"
$ go version | version ">=1.9"

Bash脚本示例:

#!/bin/bash

if `version -b ">=9.0.0" "$(gcc --version)"`; then
  echo "gcc version satisfies constraints >=9.0.0"
else
  echo "gcc version doesn't satisfies constraints >=9.0.0"
fi

如果你有coreutils-7 (Ubuntu Karmic，而不是Jaunty)，那么你的排序命令应该有一个-V选项(版本排序)，你可以使用它来进行比较:

verlte() {
    [  "$1" = "`echo -e "$1\n$2" | sort -V | head -n1`" ]
}

verlt() {
    [ "$1" = "$2" ] && return 1 || verlte $1 $2
}

verlte 2.5.7 2.5.6 && echo "yes" || echo "no" # no
verlt 2.4.10 2.4.9 && echo "yes" || echo "no" # no
verlt 2.4.8 2.4.10 && echo "yes" || echo "no" # yes
verlte 2.5.6 2.5.6 && echo "yes" || echo "no" # yes
verlt 2.5.6 2.5.6 && echo "yes" || echo "no" # no

ver_cmp()
{
    local IFS=.
    local V1=($1) V2=($2) I
    for ((I=0 ; I<${#V1[*]} || I<${#V2[*]} ; I++)) ; do
        [[ ${V1[$I]:-0} -lt ${V2[$I]:-0} ]] && echo -1 && return
        [[ ${V1[$I]:-0} -gt ${V2[$I]:-0} ]] && echo 1 && return
    done
    echo 0
}

ver_eq()
{
    [[ $(ver_cmp "$1" "$2") -eq 0 ]]
}

ver_lt()
{
    [[ $(ver_cmp "$1" "$2") -eq -1 ]]
}

ver_gt()
{
    [[ $(ver_cmp "$1" "$2") -eq 1 ]]
}

ver_le()
{
    [[ ! $(ver_cmp "$1" "$2") -eq 1 ]]
}

ver_ge()
{
    [[ ! $(ver_cmp "$1" "$2") -eq -1 ]]
}

测试:

( ( while read V1 V2 ; do echo $V1 $(ver_cmp $V1 $V2) $V2 ; done ) <<EOF
1.2.3 2.2.3
2.2.3 2.2.2
3.10 3.2
2.2 2.2.1
3.1 3.1.0
EOF
) | sed 's/ -1 / < / ; s/ 0 / = / ; s/ 1 / > /' | column -t

1.2.3  <  2.2.3
2.2.3  >  2.2.2
3.10   >  3.2
2.2    <  2.2.1
3.1    =  3.1.0


ver_lt 10.1.2 10.1.20 && echo 'Your version is too old'

Your version is too old