shell脚本返回值问题的解决

#!/bin/bash
function in_path(){
    cmd=$1
    path=$2
    oldIFS=$IFS
    IFS=":"
    retval=1
    for directory in $path
    do
     if [ -x $directory/$cmd ];then
        return 0
     fi
    done
    IFS=$oldIFS
    return 1
}
in_path ls $PATH
if [ $"yes"
else
　　echo "no"
fi

#!/bin/bash
function in_path(){
    cmd=$1
    path=$2
    oldIFS=$IFS
    IFS=":"
    retval=1
    for directory in $path
    do
     if [ -x $directory/$cmd ];then
        echo yes
     fi
    done
    IFS=$oldIFS
    echo no
}
aa=$(in_path $1 $PATH)
if [[ $aa =~ "yes" ]];then
    echo "the path has this bianliang"
else
    echo "no no no"
fi