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
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
其他回答
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
可能没有普遍正确的方法来实现这一点。如果您正在尝试比较Debian包系统中的版本,请尝试dpkg——compare-versions <first> <relation> <second>。
下面是一个不需要任何外部工具的纯Bash版本:
#!/bin/bash
vercomp () {
if [[ $1 == $2 ]]
then
return 0
fi
local IFS=.
local i ver1=($1) ver2=($2)
# fill empty fields in ver1 with zeros
for ((i=${#ver1[@]}; i<${#ver2[@]}; i++))
do
ver1[i]=0
done
for ((i=0; i<${#ver1[@]}; i++))
do
if [[ -z ${ver2[i]} ]]
then
# fill empty fields in ver2 with zeros
ver2[i]=0
fi
if ((10#${ver1[i]} > 10#${ver2[i]}))
then
return 1
fi
if ((10#${ver1[i]} < 10#${ver2[i]}))
then
return 2
fi
done
return 0
}
testvercomp () {
vercomp $1 $2
case $? in
0) op='=';;
1) op='>';;
2) op='<';;
esac
if [[ $op != $3 ]]
then
echo "FAIL: Expected '$3', Actual '$op', Arg1 '$1', Arg2 '$2'"
else
echo "Pass: '$1 $op $2'"
fi
}
# Run tests
# argument table format:
# testarg1 testarg2 expected_relationship
echo "The following tests should pass"
while read -r test
do
testvercomp $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 =
EOF
echo "The following test should fail (test the tester)"
testvercomp 1 1 '>'
运行测试:
$ . ./vercomp
The following tests should pass
Pass: '1 = 1'
Pass: '2.1 < 2.2'
Pass: '3.0.4.10 > 3.0.4.2'
Pass: '4.08 < 4.08.01'
Pass: '3.2.1.9.8144 > 3.2'
Pass: '3.2 < 3.2.1.9.8144'
Pass: '1.2 < 2.1'
Pass: '2.1 > 1.2'
Pass: '5.6.7 = 5.6.7'
Pass: '1.01.1 = 1.1.1'
Pass: '1.1.1 = 1.01.1'
Pass: '1 = 1.0'
Pass: '1.0 = 1'
Pass: '1.0.2.0 = 1.0.2'
Pass: '1..0 = 1.0'
Pass: '1.0 = 1..0'
The following test should fail (test the tester)
FAIL: Expected '>', Actual '=', Arg1 '1', Arg2 '1'
这里是另一个没有任何外部调用的纯bash解决方案:
#!/bin/bash
function version_compare {
IFS='.' read -ra ver1 <<< "$1"
IFS='.' read -ra ver2 <<< "$2"
[[ ${#ver1[@]} -gt ${#ver2[@]} ]] && till=${#ver1[@]} || till=${#ver2[@]}
for ((i=0; i<${till}; i++)); do
local num1; local num2;
[[ -z ${ver1[i]} ]] && num1=0 || num1=${ver1[i]}
[[ -z ${ver2[i]} ]] && num2=0 || num2=${ver2[i]}
if [[ $num1 -gt $num2 ]]; then
echo ">"; return 0
elif
[[ $num1 -lt $num2 ]]; then
echo "<"; return 0
fi
done
echo "="; return 0
}
echo "${1} $(version_compare "${1}" "${2}") ${2}"
还有更简单的解决方案,如果你确定所讨论的版本在第一个点后不包含前导零:
#!/bin/bash
function version_compare {
local ver1=${1//.}
local ver2=${2//.}
if [[ $ver1 -gt $ver2 ]]; then
echo ">"; return 0
elif
[[ $ver1 -lt $ver2 ]]; then
echo "<"; return 0
fi
echo "="; return 0
}
echo "${1} $(version_compare "${1}" "${2}") ${2}"
这适用于像1.2.3 vs 1.3.1 vs 0.9.7这样的版本,但不适用于其他版本 1.2.3 vs 1.2.3.0或1.01.1 vs 1.1.1
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