是否有办法在bash上比较这些字符串,例如:2.4.5和2.8和2.4.5.1?


当前回答

GNU排序有一个选项:

printf '2.4.5\n2.8\n2.4.5.1\n' | sort -V

给:

2.4.5
2.4.5.1
2.8

其他回答

GNU排序有一个选项:

printf '2.4.5\n2.8\n2.4.5.1\n' | sort -V

给:

2.4.5
2.4.5.1
2.8

与其编写冗长的代码使您的生活过于复杂,不如使用一些已经存在的东西。很多时候,当bash不够用时,python可以提供帮助。你仍然可以很容易地从bash脚本调用它(额外的好处:从bash到python的变量替换):

VERSION1=1.2.3
VERSION2=1.2.4

cat <<EOF | python3 | grep -q True
from packaging import version
print(version.parse("$VERSION1") > version.parse("$VERSION2"))
EOF

if [ "$?" == 0 ];  then
   echo "$VERSION1 is greater than $VERSION2"
else
   echo "$VERSION2 is greater or equal than $VERSION1"
fi

这里有更多信息:如何比较Python中的版本号?

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

如果你知道字段的数量,你可以用-k,n,n,得到一个超级简单的解

echo '2.4.5
2.8
2.4.5.1
2.10.2' | sort -t '.' -k 1,1 -k 2,2 -k 3,3 -k 4,4 -g

2.4.5
2.4.5.1
2.8
2.10.2

下面是对顶部答案(Dennis的)的改进,它更简洁,并使用了不同的返回值方案,以便通过单个比较轻松实现<=和>=。它还比较不是[0-9]的第一个字符之后的所有内容。]因此1.0rc1 < 1.0rc2。

# Compares two tuple-based, dot-delimited version numbers a and b (possibly
# with arbitrary string suffixes). Returns:
# 1 if a<b
# 2 if equal
# 3 if a>b
# Everything after the first character not in [0-9.] is compared
# lexicographically using ASCII ordering if the tuple-based versions are equal.
compare_versions() {
    if [[ $1 == "$2" ]]; then
        return 2
    fi
    local IFS=.
    local i a=(${1%%[^0-9.]*}) b=(${2%%[^0-9.]*})
    local arem=${1#${1%%[^0-9.]*}} brem=${2#${2%%[^0-9.]*}}
    for ((i=0; i<${#a[@]} || i<${#b[@]}; i++)); do
        if ((10#${a[i]:-0} < 10#${b[i]:-0})); then
            return 1
        elif ((10#${a[i]:-0} > 10#${b[i]:-0})); then
            return 3
        fi
    done
    if [ "$arem" '<' "$brem" ]; then
        return 1
    elif [ "$arem" '>' "$brem" ]; then
        return 3
    fi
    return 2
}

为了解决@gammazero的评论,一个(我认为)与语义版本兼容的更长的版本是:

# Compares two dot-delimited decimal-element version numbers a and b that may
# also have arbitrary string suffixes. Compatible with semantic versioning, but
# not as strict: comparisons of non-semver strings may have unexpected
# behavior.
#
# Returns:
# 1 if a<b
# 2 if equal
# 3 if a>b
compare_versions() {
    local LC_ALL=C

    # Optimization
    if [[ $1 == "$2" ]]; then
        return 2
    fi

    # Compare numeric release versions. Supports an arbitrary number of numeric
    # elements (i.e., not just X.Y.Z) in which unspecified indices are regarded
    # as 0.
    local aver=${1%%[^0-9.]*} bver=${2%%[^0-9.]*}
    local arem=${1#$aver} brem=${2#$bver}
    local IFS=.
    local i a=($aver) b=($bver)
    for ((i=0; i<${#a[@]} || i<${#b[@]}; i++)); do
        if ((10#${a[i]:-0} < 10#${b[i]:-0})); then
            return 1
        elif ((10#${a[i]:-0} > 10#${b[i]:-0})); then
            return 3
        fi
    done

    # Remove build metadata before remaining comparison
    arem=${arem%%+*}
    brem=${brem%%+*}

    # Prelease (w/remainder) always older than release (no remainder)
    if [ -n "$arem" -a -z "$brem" ]; then
        return 1
    elif [ -z "$arem" -a -n "$brem" ]; then
        return 3
    fi

    # Otherwise, split by periods and compare individual elements either
    # numerically or lexicographically
    local a=(${arem#-}) b=(${brem#-})
    for ((i=0; i<${#a[@]} && i<${#b[@]}; i++)); do
        local anns=${a[i]#${a[i]%%[^0-9]*}} bnns=${b[i]#${b[i]%%[^0-9]*}}
        if [ -z "$anns$bnns" ]; then
            # Both numeric
            if ((10#${a[i]:-0} < 10#${b[i]:-0})); then
                return 1
            elif ((10#${a[i]:-0} > 10#${b[i]:-0})); then
                return 3
            fi
        elif [ -z "$anns" ]; then
            # Numeric comes before non-numeric
            return 1
        elif [ -z "$bnns" ]; then
            # Numeric comes before non-numeric
            return 3
        else
            # Compare lexicographically
            if [[ ${a[i]} < ${b[i]} ]]; then
                return 1
            elif [[ ${a[i]} > ${b[i]} ]]; then
                return 3
            fi
        fi
    done

    # Fewer elements is earlier
    if (( ${#a[@]} < ${#b[@]} )); then
        return 1
    elif (( ${#a[@]} > ${#b[@]} )); then
        return 3
    fi

    # Must be equal!
    return 2
}