尽管 echo 显示变量相等，但相等比较在 bash 脚本中不起作用

Question

我需要确定脚本中本地设置的一个值与存储在 .txt 文件中的 git 存储库中的两个值之一相匹配。我成功地检索了这些值并将它们保存到变量 currentVersion 和 newVersion 中。我也用 dispGitTime 和 gitMESSAGE.

这样做

奇怪的是这两个比较按预期工作：

if [ "$dispGitTime" = "" ]; then dispGitTime=0; fi
if [ ! "$gitMESSAGE" = "" ]; then clear; echo "$gitMESSAGE"; sleep "$dispGitTime"; fi

但这两个比较都不行！ else 总是被调用！

if [ "$currentVersion" = "$scriptVersion" ]; then
        upToDate="true"
        printf "\n%*s" $((COLS/2)) "This script is up-to-date!"; sleep 1
    elif [ "$newVersion" = "$scriptVersion" ]; then
        upToDate="true"
        printf "\n%*s" $((COLS/2)) "This script is up-to-date!"; sleep 1

上下文的整个函数：（此函数的输出见下文）

gitConfigs(){
        terminalPath=""; terminalPath=$(pwd)
        rm -rf ~/upt; mkdir ~/upt; cd ~/upt || return

        # clone repo or update it with git pull if it exists already
        (CMD_gitGet); wait
        cd "$terminalPath" || return

        # get config values from the master branch's properties.txt
        currentVersionLine=$(grep -n "_version " ~/upt/$gitName/properties.txt); currentVersion="${currentVersionLine##* }"; echo $currentVersion
        newVersionLine=$(grep -n "_newVersion " ~/upt/$gitName/properties.txt); newVersion="${newVersionLine##* }"; echo $newVersion
        gitMESSAGELine=$(grep -n "_gitMESSAGE " ~/upt/$gitName/properties.txt); gitMESSAGE="${gitMESSAGELine##* }"
        dispGitTimeLine=$(grep -n "_dispGitTime " ~/upt/$gitName/properties.txt); dispGitTime="${dispGitTimeLine##* }"

        echo $scriptVersion; sleep 2

        # set scriptTitle to match config, else use default
        if scriptTitle=$(grep -n "_scriptTitle " ~/upt/Android-Installer/properties.txt); then
            scriptTitle="${scriptTitle##* }"
        else scriptTitle="$scriptTitleDEF"; fi

        if [ "$currentVersion" = "$scriptVersion" ]; then
            upToDate="true"
            printf "\n%*s" $((COLS/2)) "This script is up-to-date!"; sleep 1
        elif [ "$newVersion" = "$scriptVersion" ]; then
            upToDate="true"
            printf "\n%*s" $((COLS/2)) "This script is up-to-date!"; sleep 1
        else
            upToDate="false"
            printf "\n\n\n\n\n%*s\n" $((COLS/2)) "This script: v$scriptVersion"
            printf "\n%*s\n" $((COLS/2)) "Latest version: v$currentVersion"
            printf "%*s\n" $((COLS/2)) "Version in progress: v$newVersion"

            printf "\n%*s" $((COLS/2)) "Update required..."; sleep 2
            #update
        fi

        # display gitMESSAGE if there is one
        if [ "$dispGitTime" = "" ]; then dispGitTime=0; fi
        if [ ! "$gitMESSAGE" = "" ]; then clear; echo "$gitMESSAGE"; sleep "$dispGitTime"; fi
    }

输出：

1.1.6-beta
1.1.7-release
1.1.7-release





                                            This script: v1.1.7-release

                                           Latest version: v1.1.6-beta
                                   Version in progress: v1.1.7-release

                                                     Update required...

Answer 1

问题是根据@JohnKugelman 的declare -p varname | cat -v 建议发现的。

这些变量的末尾确实有^M回车returns。

我在这里找到了删除它们的方法：unix.stackexchange

解决方案？添加：

currentVersion=${currentVersion%$'\r'}

newVersion=${newVersion%$'\r'}

尽管 echo 显示变量相等，但相等比较在 bash 脚本中不起作用

Equality comparison not working in bash script despite echo showing variables are equal

bash

comparison