shell 判断二进制是否可用

# 结果是yes
checkCmd='docker --version'
res=`eval $checkCmd 1>/dev/null 2>&1; echo -n $?`
resStr=`echo -n $res`
if [[ "$resStr" == "0" ]]; thenecho "yes"
elseecho "no"
fi# 结果是no
checkCmd='docker1 --version'
res=`eval $checkCmd 1>/dev/null 2>&1; echo -n $?`
resStr=`echo -n $res`
if [[ "$resStr" == "0" ]]; thenecho "yes"
elseecho "no"
fi