什么是curl"-s"和"-m"的意思

Question

我在crontab中找到了以下内容

* * * * * sleep 5; curl -s -m 10 http://url > /dev/null 2>&1
* * * * * sleep 10; curl -s -m 10 http://url > /dev/null 2>&1
* * * * * sleep 15; curl -s -m 10 http://url > /dev/null 2>&1
* * * * * sleep 20; curl -s -m 10 http://url > /dev/null 2>&1
* * * * * sleep 25; curl -s -m 10 http://url > /dev/null 2>&1
* * * * * sleep 30; curl -s -m 10 http://url > /dev/null 2>&1
* * * * * sleep 35; curl -s -m 10 http://url > /dev/null 2>&1
* * * * * sleep 40; curl -s -m 10 http://url > /dev/null 2>&1
* * * * * sleep 45; curl -s -m 10 http://url > /dev/null 2>&1
* * * * * sleep 50; curl -s -m 10 http://url > /dev/null 2>&1
* * * * * sleep 55; curl -s -m 10 http://url > /dev/null 2>&1

那么curl -s -m 10这里的含义是什么？

Answer 1

从 man curl

--snip--

-m, --max-time <seconds>
              Maximum time in seconds that you allow the whole operation to take.  This is useful for preventing your batch jobs from hanging for hours due to  slow  networks
              or  links  going down.  Since 7.32.0, this option accepts decimal values, but the actual timeout will decrease in accuracy as the specified timeout increases in
              decimal precision.  See also the --connect-timeout option.

              If this option is used several times, the last one will be used.

--snip--

-s, --silent
              Silent  or  quiet mode. Don't show progress meter or error messages.  Makes Curl mute. It will still output the data you ask for, potentially even to the termi-
              nal/stdout unless you redirect it.