linux-bash-获取时间-字符串拼接-比较版本号大小

timenow=$(date "+%Y%m%d")      输出：20220425
tarname=$timenow".tar"  输出：20220425.tar

注：字符串赋值=前不能有空格

比较版本号大小参考

#!/bin/bash
 
VERSION=$1
VERSION2=$2
 
function version_gt() { test "$(echo "$@" | tr " " "\n" | sort -V | head -n 1)" != "$1"; }
function version_le() { test "$(echo "$@" | tr " " "\n" | sort -V | head -n 1)" == "$1"; }
function version_lt() { test "$(echo "$@" | tr " " "\n" | sort -rV | head -n 1)" != "$1"; }
function version_ge() { test "$(echo "$@" | tr " " "\n" | sort -rV | head -n 1)" == "$1"; }
 
if version_gt $VERSION $VERSION2; then
   echo "$VERSION is greater than $VERSION2"
fi
 
if version_le $VERSION $VERSION2; then
   echo "$VERSION is less than or equal to $VERSION2"
fi
 
if version_lt $VERSION $VERSION2; then
   echo "$VERSION is less than $VERSION2"
fi
 
if version_ge $VERSION $VERSION2; then
   echo "$VERSION is greater than or equal to $VERSION2"
fi