shell - 根据运行时信息构造命令
问题描述
我需要在 ash 中运行一个 shell 脚本。如何解决缺少用于动态构建命令的数组而不会遇到问题的问题?
这是我要修复的代码块:
CURL_ARGS=('--noproxy' '*' '--verbose' '--silent' '--include' '--write-out' '%{http_code}')
if [ "$CURL_HOST_HEADER" != "" ]; then CURL_ARGS+=(--header "$CURL_HOST_HEADER"); fi
CURL_ARGS+=("http://$CURL_HOST:$CURL_PORT$CURL_PATH")
echo Proceeding with curl cmd: curl "${CURL_ARGS[@]}"
n=0
until [ $n -ge 5 ]
do
n=$[$n+1]
CURL_RESPONSE=$(curl "${CURL_ARGS[@]}")
PAGE=${CURL_RESPONSE:0:-3}
HTTP_STATUS=${CURL_RESPONSE: -3}
if [ "$HTTP_STATUS" != "200" ]
then
echo "Curl failed with http status $HTTP_STATUS. Retrying shortly if attempts remain"
sleep 15
else
break
fi
done
if [ "$HTTP_STATUS" != "200" ]
then
LOGFILE=curlable-error-page-$(date +%s).html
echo "CURL CMD:" > $LOGFILE
echo "curl ${CURL_ARGS[@]}" >> $LOGFILE
echo "STATUS:" >> $LOGFILE
echo "$HTTP_STATUS" >> $LOGFILE
echo "RESPONSE:" >> $LOGFILE
echo "$PAGE" >> $LOGFILE
exit 1
fi
解决方案
如果没有数组,您的下一个最佳选择是定义一个函数,以便您可以利用其(未使用的)位置参数充当伪数组。
作为示例,我将假装标头作为参数传递,而不是作为全局变量(如主机、端口和路径)进行访问。
run_curl () {
# save any arguments first
curl_host_header=$1
# Repurpose $@ for use when you call curl
set -- '--noproxy' '*' '--verbose' '--silent' '--include' '--write-out' '%{http_code}'
if [ -n "$curl_host_header" ]; then
set -- "$@" --header "$curl_host_header"
fi
set -- "http://$CURL_HOST:$CURL_PORT$CURL_PATH"
n=0
until [ "$n" -ge 5 ]
do
n=$(($n+1))
curl_response=$(curl "$@")
page=${curl_response:0:-3}
http_status=${curl_response : -3}
if [ "$http_status" != "200" ]
then
echo "Curl failed with http status $HTTP_STATUS. Retrying shortly if attempts remain"
sleep 15
else
break
fi
done
if [ "$http_status" != "200" ]
then
logfile=curlable-error-page-$(date +%s).html
{
echo "CURL CMD:"
echo "curl $*" # $* is fine for embedding in a larger string
echo "STATUS:"
echo "$http_status"
echo "RESPONSE:"
echo "$page"
} > "$logfile"
exit 1
fi
}
run_curl # No extra headers
run_curl "$CURL_HOST_HEADER" # Extra header