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

感谢Dennis的解决方案,我们可以扩展它以允许比较运算符'>','<','=','==','<='和'>='。

# compver ver1 '=|==|>|<|>=|<=' ver2
compver() { 
    local op
    vercomp $1 $3
    case $? in
        0) op='=';;
        1) op='>';;
        2) op='<';;
    esac
    [[ $2 == *$op* ]] && return 0 || return 1
}

然后我们可以在表达式中使用比较运算符,比如:

compver 1.7 '<=' 1.8
compver 1.7 '==' 1.7
compver 1.7 '=' 1.7

并且只测试结果的真/假,比如:

if compver $ver1 '>' $ver2; then
    echo "Newer"
fi

其他回答

我使用嵌入式Linux (Yocto)与BusyBox。BusyBox排序没有-V选项(但BusyBox expr匹配可以做正则表达式)。所以我需要一个Bash版本的比较,它适用于这个约束。

我做了以下(类似于Dennis Williamson的回答)来比较使用“自然排序”类型的算法。它将字符串分成数字部分和非数字部分;它以数字方式比较数字部分(因此10大于9),并以纯ASCII方式比较非数字部分。

ascii_frag() {
    expr match "$1" "\([^[:digit:]]*\)"
}

ascii_remainder() {
    expr match "$1" "[^[:digit:]]*\(.*\)"
}

numeric_frag() {
    expr match "$1" "\([[:digit:]]*\)"
}

numeric_remainder() {
    expr match "$1" "[[:digit:]]*\(.*\)"
}

vercomp_debug() {
    OUT="$1"
    #echo "${OUT}"
}

# return 1 for $1 > $2
# return 2 for $1 < $2
# return 0 for equal
vercomp() {
    local WORK1="$1"
    local WORK2="$2"
    local NUM1="", NUM2="", ASCII1="", ASCII2=""
    while true; do
        vercomp_debug "ASCII compare"
        ASCII1=`ascii_frag "${WORK1}"`
        ASCII2=`ascii_frag "${WORK2}"`
        WORK1=`ascii_remainder "${WORK1}"`
        WORK2=`ascii_remainder "${WORK2}"`
        vercomp_debug "\"${ASCII1}\" remainder \"${WORK1}\""
        vercomp_debug "\"${ASCII2}\" remainder \"${WORK2}\""

        if [ "${ASCII1}" \> "${ASCII2}" ]; then
            vercomp_debug "ascii ${ASCII1} > ${ASCII2}"
            return 1
        elif [ "${ASCII1}" \< "${ASCII2}" ]; then
            vercomp_debug "ascii ${ASCII1} < ${ASCII2}"
            return 2
        fi
        vercomp_debug "--------"

        vercomp_debug "Numeric compare"
        NUM1=`numeric_frag "${WORK1}"`
        NUM2=`numeric_frag "${WORK2}"`
        WORK1=`numeric_remainder "${WORK1}"`
        WORK2=`numeric_remainder "${WORK2}"`
        vercomp_debug "\"${NUM1}\" remainder \"${WORK1}\""
        vercomp_debug "\"${NUM2}\" remainder \"${WORK2}\""

        if [ -z "${NUM1}" -a -z "${NUM2}" ]; then
            vercomp_debug "blank 1 and blank 2 equal"
            return 0
        elif [ -z "${NUM1}" -a -n "${NUM2}" ]; then
            vercomp_debug "blank 1 less than non-blank 2"
            return 2
        elif [ -n "${NUM1}" -a -z "${NUM2}" ]; then
            vercomp_debug "non-blank 1 greater than blank 2"
            return 1
        fi

        if [ "${NUM1}" -gt "${NUM2}" ]; then
            vercomp_debug "num ${NUM1} > ${NUM2}"
            return 1
        elif [ "${NUM1}" -lt "${NUM2}" ]; then
            vercomp_debug "num ${NUM1} < ${NUM2}"
            return 2
        fi
        vercomp_debug "--------"
    done
}

它可以比较更复杂的版本号,例如

1.2-r3和1.2-r4 1.2 r3 vs 1.2r4

请注意,对于Dennis Williamson的回答中的一些极端情况,它不会返回相同的结果。特别是:

1            1.0          <
1.0          1            >
1.0.2.0      1.0.2        >
1..0         1.0          >
1.0          1..0         <

但这些都是极端情况,我认为结果仍然是合理的。

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

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
}

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

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