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

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
}

其他回答

我不喜欢这些解决方案,因为它们漏洞百出、不可移植等等。

我(目前)努力提出一个更好的解决方案……src: version_compare(),测试

Sorta-copied /贴在这里……

来源:

##
# Compare two versions.
#
# **Usage:** version_compare version1 operator version2
#
# - operator:
#
#   + ``lesser_than``, ``-lt``, ``<``
#   + ``lesser_than_or_equal``, ``-le``, ``<=``
#   + ``greater_than``, ``-gt``, ``>``
#   + ``greater_than_or_equal``, ``-ge``, ``>=``
#   + ``equal``, ``-eq``, ``==``
#   + ``not_equal``, ``-ne``, ``!=``
#
# - version{1,2}: arbitrary version strings to compare
#
# **Version Format:** ``[0-9]+($VERSION_SEPARATOR[0-9]+)*`` (i.e. 1, 1.0, 90, 1.2.3.4)
#
# **Returns:** true if comparison statement is correct
##
version_compare() {
    _largest_version "$1" "$3"; _cmp="$(printf '%s' "$?")"

    # Check for valid responses or bail early
    case "$_cmp" in
        1|0|2) :;;
        *) _die "$_cmp" 'version comparison failed';;
    esac

    # The easy part
    case "$2" in
        'lesser_than'|'-lt'|'<')
            [ "$_cmp" = '2' ] && return 0
            ;;
        'lesser_or_equal'|'-le'|'<=')
            [ "$_cmp" = '0' ] && return 0
            [ "$_cmp" = '2' ] && return 0
            ;;
        'greater_than'|'-gt'|'>')
            [ "$_cmp" = '1' ] && return 0
            ;;
        'greater_or_equal'|'-ge'|'>=')
            [ "$_cmp" = '1' ] && return 0
            [ "$_cmp" = '0' ] && return 0
            ;;
        'equal'|'-eq'|'==')
            [ "$_cmp" = '0' ] && return 0
            ;;
        'not_equal'|'-ne'|'!=')
            [ "$_cmp" = '1' ] && return 0
            [ "$_cmp" = '2' ] && return 0
            ;;
        *) _die 7 'Unknown operatoration called for version_compare().';;
    esac
    return 1
}

##
# Print a formatted (critical) message and exit with status.
#
# **Usage:** _die [exit_status] message
#
# - exit_status: exit code to use with script termination (default: 1)
# - message: message to print before terminating script execution
##
_die() {
        # If first argument was an integer, use as exit_status
        if [ "$1" -eq "$1" ] 2>/dev/null; then
                _exit_status="$1"; shift
        else
                _exit_status=1
        fi

        printf '*** CRITICAL: %s ***\n' "$1"
        exit "$_exit_status"
}

##
# Compare two versions.
# Check if one version is larger/smaller/equal than/to another.
#
# **Usage:** _largest_version ver1 ver2
#
# Returns: ($1 > $2): 1 ; ($1 = $2): 0 ; ($1 < $2): 2
# [IOW- 1 = $1 is largest; 0 = neither ; 2 = $2 is largest]
##
_largest_version() (
    # Value used to separate version components
    VERSION_SEPARATOR="${VERSION_SEPARATOR:-.}"

    for _p in "$1" "$2"; do
        [ "$(printf %.1s "$_p")" = "$VERSION_SEPARATOR" ] &&
            _die 7 'invalid version pattern provided'
    done

    # Split versions on VER_SEP into int/sub
    _v="$1$2"
    _v1="$1"
    _s1="${1#*$VERSION_SEPARATOR}"
    if [ "$_v1" = "$_s1" ]; then
        _s1=''
        _m1="$_v1"
    else
        _m1="${1%%$VERSION_SEPARATOR*}"
    fi
    _v2="$2"
    _s2="${2#*$VERSION_SEPARATOR}"
    if [ "$_v2" = "$_s2" ]; then
        _s2=''
        _m2="$_v2"
    else
        _m2="${2%%$VERSION_SEPARATOR*}"
    fi

    # Both are equal
    [ "$_v1" = "$_v2" ] && return 0

    # Something is larger than nothing (30 < 30.0)
    if [ -n "$_v1" ] && [ ! -n "$_v2" ]; then
        return 1
    elif [ ! -n "$_v1" ] && [ -n "$_v2" ]; then
        return 2
    fi

    # Check for invalid
    case "$_m1$_m2" in
        *[!0-9]*)
            _die 7 'version_compare called with unsupported version type'
            ;;
    esac

    # If a ver_sep is present
    if [ "${_v#*$VERSION_SEPARATOR}" != "$_v" ]; then
        # Check for a larger "major" version number
        [ "$_m1" -lt "$_m2" ] && return 2
        [ "$_m1" -gt "$_m2" ] && return 1

        # Compare substring components
        _largest_version "$_s1" "$_s2"; return "$?"
    else
        # Only integers present; simple integer comparison
        [ "$_v1" -lt "$_v2" ] && return 2
        [ "$_v1" -gt "$_v2" ] && return 1
    fi
)

测试:

# Simple test of all operators
( version_compare '1' 'lesser_than' '2' ); [ "$?" = '0' ] || return 1
( version_compare '2' 'equal' '2' ); [ "$?" = '0' ] || return 1
( version_compare '3' 'not_equal' '1' ); [ "$?" = '0' ] || return 1
( version_compare '2' 'greater_than' '1' ); [ "$?" = '0' ] || return 1
( version_compare '1' '-lt' '2' ); [ "$?" = '0' ] || return 1
( version_compare '2' '-eq' '2' ); [ "$?" = '0' ] || return 1
( version_compare '3' '-ne' '1' ); [ "$?" = '0' ] || return 1
( version_compare '2' '-gt' '1' ); [ "$?" = '0' ] || return 1

# Semver test of primary operators (expect true)
( version_compare '7.0.1' '-lt' '7.0.2' ); [ "$?" = '0' ] || return 1
( version_compare '7.0.2' '-eq' '7.0.2' ); [ "$?" = '0' ] || return 1
( version_compare '3.0.2' '-ne' '2.0.7' ); [ "$?" = '0' ] || return 1
( version_compare '7.0.2' '-gt' '7.0.1' ); [ "$?" = '0' ] || return 1

# Semver test of primary operators (expect false)
( version_compare '7.0.2' '-lt' '7.0.1' ); [ "$?" = '1' ] || return 1
( version_compare '3.0.2' '-eq' '2.0.7' ); [ "$?" = '1' ] || return 1
( version_compare '7.0.2' '-ne' '7.0.2' ); [ "$?" = '1' ] || return 1
( version_compare '7.0.1' '-gt' '7.0.2' ); [ "$?" = '1' ] || return 1

# Mismatched version strings (expect true)
( version_compare '7' '-lt' '7.1' ); [ "$?" = '0' ] || return 1
( version_compare '3' '-ne' '7.0.0' ); [ "$?" = '0' ] || return 1
( version_compare '7.0.1' '-gt' '7' ); [ "$?" = '0' ] || return 1

# Mismatched version strings (expect false)
( version_compare '7.0.0' '-eq' '7.0' ); [ "$?" = '1' ] || return 1

# Invalid operation supplied
( version_compare '2' '-inv' '1' >/dev/null ); [ "$?" = '7' ] || return 1

# Invalid version formats
( version_compare '1..0' '==' '1.0' >/dev/null ); [ "$?" = '7' ] || return 1
( version_compare '1.0' '==' '1..0' >/dev/null ); [ "$?" = '7' ] || return 1
( version_compare '1.0' '==' '1.0b7' >/dev/null ); [ "$?" = '7' ] || return 1
( version_compare '1.0a' '==' '1.0' >/dev/null ); [ "$?" = '7' ] || return 1

# "how does that handle comparing 10.0.0 (not a number) to 2.0 (a number)?"
( version_compare '10.0.0' '-lt' '2.0' ); [ "$?" = '1' ] || return 1
( version_compare '10.0' '-gt' '2.0.0' ); [ "$?" = '0' ] || return 1

# not less/greater-than... but equal
( version_compare '7' '-lt' '7' ); [ "$?" = '1' ] || return 1
( version_compare '7' '-gt' '7' ); [ "$?" = '1' ] || return 1

# String vs. numerical comparison
( version_compare '1.18.1' '-gt' '1.8.1' ); [ "$?" = '0' ] || return 1


# Random tests found on the internet
( version_compare '1' '==' '1' ); [ "$?" = '0' ] || return 1
( version_compare '2.1' '<' '2.2' ); [ "$?" = '0' ] || return 1
( version_compare '3.0.4.10' '>' '3.0.4.2' ); [ "$?" = '0' ] || return 1
( version_compare '4.08' '<' '4.08.01' ); [ "$?" = '0' ] || return 1
( version_compare '3.2.1.9.8144' '>' '3.2' ); [ "$?" = '0' ] || return 1
( version_compare '3.2' '<' '3.2.1.9.8144' ); [ "$?" = '0' ] || return 1
( version_compare '1.2' '<' '2.1' ); [ "$?" = '0' ] || return 1
( version_compare '2.1' '>' '1.2' ); [ "$?" = '0' ] || return 1
( version_compare '5.6.7' '==' '5.6.7' ); [ "$?" = '0' ] || return 1
( version_compare '1.01.1' '==' '1.1.1' ); [ "$?" = '0' ] || return 1
( version_compare '1.1.1' '==' '1.01.1' ); [ "$?" = '0' ] || return 1
( version_compare '1' '!=' '1.0' ); [ "$?" = '0' ] || return 1
( version_compare '1.0.0' '!=' '1.0' ); [ "$?" = '0' ] || return 1

对于旧版本/busybox排序。简单的形式提供了粗略的结果,往往奏效。

sort -n

这是特别有用的版本,其中包含alpha符号,如

10.c.3
10.a.4
2.b.5

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

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?

我的观点是:

vercomp () {
    if [[ "${1}" == "${2}" ]]; then
        echo '0'
        return
    fi
    echo "${1}" | sed 's/\([0-9]\+\)\./\1\n/g' | {
        _RES_=-1
        for _VB_ in $(echo "${2}" | sed 's/\([0-9]\+\)\./\1\n/g'); do
            if ! read -r _VA_ || [[ "${_VB_}" -gt "${_VA_}" ]]; then
                _RES_=1
                break
            fi
        done
        read -r _VA_ && echo '-1' || echo "${_RES_}"
    }
}

语法:

vercomp VERSION_A VERSION_B

打印:

-1如果VERSION_A是最近的版本 如果两个版本相等,则为0 如果VERSION_B是最近的版本,则为1