如果grep找到了它正在寻找的东西,那就做X else Y.

时间:2012-10-23 06:41:14

标签: bash grep

在此语句中,如果路径/ app / $ var1(应用程序名称)中存在版本($ var2),我将尝试匹配

if 
find /app/$var1 -maxdepth 1 -type l -o -type d | grep $var2 #results in a nice list where i can manually get a true match.
# if match is found then execute command.
$realcmd "$@"
    rc=$?
    exit $rc
else
echo "no match, the version you are looking for does not exist"
fi

当前代码: 这包括我的所有代码(未清理)。 命令我运行:“./ xmodule load firefox / 3.6.12” 此版本确实退出

#!/bin/bash
# hook for some commands

#echo $@  #value of sting that is entered after "xmodule"

cmd=$(basename "$0")
#echo "called as $cmd"

if [[ $cmd = "xmodule" ]]
then
    realcmd='/app/modules/0/bin/modulecmd tcsh'

    # verify parameters
fi
# check if $@ contains value "/" to determine if a specific version is requested.
case "$@" in
*/*)
    echo "has slash"
var1=$(echo "$@" | grep -Eio '\s\w*') # Gets the aplication name and put it into var1
echo $var1   # is not printed should be "firefox"
var2=$(echo "$@" | grep -o '[^/]*$')  # Gets version name and put it into var2 
echo $var2 
# Checking if version number exist in /app/appname/
if find /app/$var1 -noleaf -maxdepth 1 -type l -o -type d | grep $var2; then
    $realcmd "$@"
    exit $?
else
    echo "no match, the version you are looking for does not exist"
    # Should there be an exit here?
fi
    ;;

*)
    echo "doesn't have a slash"
    ;;
esac

输出: mycomputer [上午9:55] [用户/桌面/脚本] - > ./xmodule加载firefox / 3.6.12 '有斜线

3.6.12 不匹配,您要查找的版本不存在

如果有空白(3.6.1以上),则应该有应用程序名称。我现在意识到这一定是我的问题,它使用的路径我可能只是/ app。 但我不认为我在代码的那一部分有任何改变。

2 个答案:

答案 0 :(得分:27)

您可以使用整个grep管道作为if语句的条件。使用grep -q使其无法打印找到的匹配项(除非您希望打印)。我还简化了退出(如果您要立即使用它,则无需在变量中存储$?)。结果如下:

if find "/app/$var1" -maxdepth 1 -type l -o -type d | grep -q "$var2"; then
    $realcmd "$@"
    exit $?
else
    echo "no match, the version you are looking for does not exist"
    # Should there be an exit here?
fi
顺便说一下,既然你要在$ realcmd之后立即退出,你可以使用exec $realcmd "$@"用$ realcmd替换shell,而不是将$ realcmd作为子进程运行。

答案 1 :(得分:19)

来自grep联机帮助页:

  

如果找到选定的行,则退出状态为0,如果未找到,则退出状态为1。如果发生错误,退出状态为2。

换句话说,紧跟blah blah | grep $var2之后,只需检查返回值。

由于管道的退出代码是该管道中最后一个进程的退出代码,因此您可以使用以下内容:

find /app/$var1 -maxdepth 1 -type l -o -type d | grep $var2
greprc=$?
if [[ $greprc -eq 0 ]] ; then
    echo Found
else
    if [[ $greprc -eq 1 ]] ; then
        echo Not found
    else
        echo Some sort of error
    fi
fi