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
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
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} < ${NUM2}"
return 2
fi
vercomp_debug "--------"
done
}
它可以比较更复杂的版本号,例如
1.2-r3和1.2-r4 1.2 r3 vs 1.2r4
请注意,对于Dennis Williamson的回答中的一些极端情况,它不会返回相同的结果。特别是:
1 1.0 <
1.0 1 >
1.0.2.0 1.0.2 >
1..0 1.0 >
1.0 1..0 <
但这些都是极端情况,我认为结果仍然是合理的。
function version { echo "$@" | awk -F. '{ printf("%d%03d%03d%03d\n", $1,$2,$3,$4); }'; }
这样用:
if [ $(version $VAR) -ge $(version "6.2.0") ]; then
echo "Version is up to date"
fi
(来自https://apple.stackexchange.com/a/123408/11374)
我实现了另一个比较器函数。这一个有两个特定的要求:(i)我不希望函数失败使用返回1,但echo代替;(ii)当我们从git存储库中检索版本时,版本“1.0”应该大于“1.0.2”,这意味着“1.0”来自trunk。
function version_compare {
IFS="." read -a v_a <<< "$1"
IFS="." read -a v_b <<< "$2"
while [[ -n "$v_a" || -n "$v_b" ]]; do
[[ -z "$v_a" || "$v_a" -gt "$v_b" ]] && echo 1 && return
[[ -z "$v_b" || "$v_b" -gt "$v_a" ]] && echo -1 && return
v_a=("${v_a[@]:1}")
v_b=("${v_b[@]:1}")
done
echo 0
}
请随意评论并提出改进建议。
这里有一个支持修订的纯Bash解决方案(例如。“1.0-r1”),答案是基于丹尼斯·威廉姆森(Dennis Williamson)发布的答案。可以很容易地修改它以支持'-RC1'之类的东西,或者通过更改正则表达式从更复杂的字符串中提取版本。
有关实现的详细信息,请参考代码内注释和/或启用包含的调试代码:
#!/bin/bash
# Compare two version strings [$1: version string 1 (v1), $2: version string 2 (v2)]
# Return values:
# 0: v1 == v2
# 1: v1 > v2
# 2: v1 < v2
# Based on: https://stackoverflow.com/a/4025065 by Dennis Williamson
function compare_versions() {
# Trivial v1 == v2 test based on string comparison
[[ "$1" == "$2" ]] && return 0
# Local variables
local regex="^(.*)-r([0-9]*)$" va1=() vr1=0 va2=() vr2=0 len i IFS="."
# Split version strings into arrays, extract trailing revisions
if [[ "$1" =~ ${regex} ]]; then
va1=(${BASH_REMATCH[1]})
[[ -n "${BASH_REMATCH[2]}" ]] && vr1=${BASH_REMATCH[2]}
else
va1=($1)
fi
if [[ "$2" =~ ${regex} ]]; then
va2=(${BASH_REMATCH[1]})
[[ -n "${BASH_REMATCH[2]}" ]] && vr2=${BASH_REMATCH[2]}
else
va2=($2)
fi
# Bring va1 and va2 to same length by filling empty fields with zeros
(( ${#va1[@]} > ${#va2[@]} )) && len=${#va1[@]} || len=${#va2[@]}
for ((i=0; i < len; ++i)); do
[[ -z "${va1[i]}" ]] && va1[i]="0"
[[ -z "${va2[i]}" ]] && va2[i]="0"
done
# Append revisions, increment length
va1+=($vr1)
va2+=($vr2)
len=$((len+1))
# *** DEBUG ***
#echo "TEST: '${va1[@]} (?) ${va2[@]}'"
# Compare version elements, check if v1 > v2 or v1 < v2
for ((i=0; i < len; ++i)); do
if (( 10#${va1[i]} > 10#${va2[i]} )); then
return 1
elif (( 10#${va1[i]} < 10#${va2[i]} )); then
return 2
fi
done
# All elements are equal, thus v1 == v2
return 0
}
# ---------- everything below this line is just for testing ----------
# Test compare_versions [$1: version string 1, $2: version string 2, $3: expected result]
function test_compare_versions() {
local op
compare_versions "$1" "$2"
case $? in
0) op="==" ;;
1) op=">" ;;
2) op="<" ;;
esac
if [[ "$op" == "$3" ]]; then
echo -e "\e[1;32mPASS: '$1 $op $2'\e[0m"
else
echo -e "\e[1;31mFAIL: '$1 $3 $2' (result: '$1 $op $2')\e[0m"
fi
}
echo -e "\nThe following tests should pass:"
while read -r test; do
test_compare_versions $test
done << EOF
1 1 ==
2.1 2.2 <
3.0.4.10 3.0.4.2 >
4.08 4.08.01 <
3.2.1.9.8144 3.2 >
3.2 3.2.1.9.8144 <
1.2 2.1 <
2.1 1.2 >
5.6.7 5.6.7 ==
1.01.1 1.1.1 ==
1.1.1 1.01.1 ==
1 1.0 ==
1.0 1 ==
1.0.2.0 1.0.2 ==
1..0 1.0 ==
1.0 1..0 ==
1.0-r1 1.0-r3 <
1.0-r9 2.0 <
3.0-r15 3.0-r9 >
...-r1 ...-r2 <
2.0-r1 1.9.8.21-r2 >
1.0 3.8.9.32-r <
-r -r3 <
-r3 -r >
-r3 -r3 ==
-r -r ==
0.0-r2 0.0.0.0-r2 ==
1.0.0.0-r2 1.0-r2 ==
0.0.0.1-r7 -r9 >
0.0-r0 0 ==
1.002.0-r6 1.2.0-r7 <
001.001-r2 1.1-r2 ==
5.6.1-r0 5.6.1 ==
EOF
echo -e "\nThe following tests should fail:"
while read -r test; do
test_compare_versions $test
done << EOF
1 1 >
3.0.5-r5 3..5-r5 >
4.9.21-r3 4.8.22-r9 <
1.0-r 1.0-r1 ==
-r 1.0-r >
-r1 0.0-r1 <
-r2 0-r2 <
EOF
当Bash变得太复杂时,就把它输送到python中!
vercomp(){ echo "$1" "$2" | python3 -c "import re, sys; arr = lambda x: list(map(int, re.split('[^0-9]+', x))); x, y = map(arr, sys.stdin.read().split()); exit(not x >= y)"; }
比较两个版本号的例子:
vercomp 2.8 2.4.5 && echo ">=" || echo "<"
这个python一行代码比较左边版本号和右边版本号,如果左边版本号等于或更高,则退出0。它还处理2.4.5rc3这样的版本
分解后,这是可读的代码:
import re, sys
# Convert a version string into a list "2.4.5" -> [2, 4, 5]
arr = lambda x: list(map(int, re.split('[^0-9]+', x)))
# Read the version numbers from stdin and apply the above function to them
x, y = map(arr, sys.stdin.read().split())
# Exit 0 if the left number is greater than the right
exit(not x >= y)