Usage: curl [options...] <url>      --abstract-unix-socket <path> Connect via abstract Unix domain socket      --alt-svc <file name> Enable alt-svc with this cache file      --anyauth       Pick any authentication method  -a, --append        Append to target file when uploading      --basic         Use HTTP Basic Authentication      --cacert <file> CA certificate to verify peer against      --capath <dir>  CA directory to verify peer against  -E, --cert <certificate[:password]> Client certificate file and password      --cert-status   Verify the status of the server certificate      --cert-type <type> Certificate file type (DER/PEM/ENG)      --ciphers <list of ciphers> SSL ciphers to use      --compressed    Request compressed response      --compressed-ssh Enable SSH compression  -K, --config <file> Read config from a file      --connect-timeout <seconds> Maximum time allowed for connection      --connect-to <HOST1:PORT1:HOST2:PORT2> Connect to host  -C, --continue-at <offset> Resumed transfer offset 

比如-a 后面有很多个--axxxxx 是表示如果只写-a 就默认是后面刚好正对的那个--append 吗