curl

• manpage
• -J 使用服务端返回的名字
• --remote-name-all
  • 默认 -O 只影响第一个
• 支持协议
  • file
  • sftp, ftp, ftps
  • dict gopher gophers http https imap imaps ldap ldaps mqtt pop3 pop3s rtsp smb smbs smtp smtps telnet tftp

# 测试 SNI
# resolve 不可以指定远程 port
# connect-to 可以指定 port
curl -vik --resolve example.com:8443:127.0.0.1 https://example.com:8443
curl -vik --resolve example.com:443:127.0.0.1 https://example.com

curl -vik --connect-to example.com:443:127.0.0.1:8443 https://example.com

curl -H "Host: www.example.com" http://localhost/

# 协议限定
curl --http1.1 --no-alpn --no-npn --tlsv1.2 --tls-max 1.2 https://example.com

curl -sI https://curl.se -o/dev/null -w '%{http_version}\n'
curl -sI --http3 https://curl.se -o/dev/null -w '%{http_version}\n'

flag	since	for
-X, --request <method>
-x, --proxy [protocol://]host[:port]		https?,socks{4,5}{a,h}
--json <data>	7.82	--data+POST+Content-Type+Accept
--output-dir <dir>	7.73	指定输出目录
--create-dirs		创建输出目录 mode=0750
-C, --continue-at <offset>		继续下载
--remote-name-all		全部使用 remote-name - URL 文件名部分 - -O 只影响第一个
-O, --remote-name		第一个使用 remote-name
-J, --remote-header-name		使用 Content-Disposition 头里的文件名
--create-file-mode <mode>	7.75
--dns-servers NS	7.33	c-ares
-Z, --parallel	7.66
--parallel-max <num>		50
--haproxy-protocol		测试 HAProxy 代理

• proxy
  • port=1080
  • socks5h - 使用 代理 resolve 名字而非本地 dns
  • -p, --proxytunnel - 使用 HTTP CONNECT

curl -LOJC- https://example.com/pancakes.jpg # 继续上次下载位置

# 下载到指定目录，目录不存在则创建
curl --create-dirs -O --output-dir /tmp/receipes https://example.com/pancakes.jpg

测试 CORS

curl --head \
  -H "Origin: http://example.com" \
  -H "Access-Control-Request-Method: POST" \
  -H "Access-Control-Request-Headers: X-Requested-With" \
  -X OPTIONS --verbose \
  https://www.googleapis.com/discovery/v1/apis

延时

# %{stderr} 写入到 stderr
cat << EOF > curl-format.txt
     time_namelookup:  %{time_namelookup}s\n
        time_connect:  %{time_connect}s\n
     time_appconnect:  %{time_appconnect}s\n
    time_pretransfer:  %{time_pretransfer}s\n
       time_redirect:  %{time_redirect}s\n
  time_starttransfer:  %{time_starttransfer}s\n
                      ----------\n
          time_total:  %{time_total}s\n
EOF
# https://everything.curl.dev/usingcurl/verbose/writeout
curl -o /dev/null -s -w "@curl-format.txt" https://wener.me
cat curl-format.txt | curl -o /dev/null -s -w @- https://wener.me

     time_namelookup:  0.001639s
        time_connect:  1.230475s
     time_appconnect:  1.708174s
    time_pretransfer:  1.708254s
       time_redirect:  0.000000s
  time_starttransfer:  1.962050s
                      ----------
          time_total:  1.971632s

FAQ

websocket

curl --include \
  --no-buffer \
  --header "Connection: Upgrade" \
  --header "Upgrade: websocket" \
  --header "Host: example.com:80" \
  --header "Origin: http://example.com:80" \
  --header "Sec-WebSocket-Key: SGVsbG8sIHdvcmxkIQ==" \
  --header "Sec-WebSocket-Version: 13" \
  http://example.com:80/

# https://github.com/vi/websocat
apk add websocat

websocat -vv 'wss://'

Mark bundle as not supporting multiuse

• HTTP/2 检测
• lib/http.c#L4276-L4279

if(conn->httpversion < 20) {
   conn->bundle->multiuse = BUNDLE_NO_MULTIUSE;
   infof(data, "Mark bundle as not supporting multiuse\n");
}

bad range specification in URL position

• -g/--globoff

curl -g "https://wener.me/[1,2]"

CApath: none

CAfile: /etc/ssl/certs/ca-certificates.crt
CApath: none

• CURL_CA_BUNDLE

# /usr/share/ca-certificates
apk add ca-certificates

# /etc/ssl/certs/ca-certificates.crt
# /etc/ssl/cert.pem
# /etc/ssl1.1/cert.pem
# /etc/ssl1.1/certs
apk add ca-certificates-bundle

hang after TLS handshake, Client hello

• 可能是 MTU 问题
• docker in docker 的时候出现了，调低 mtu
  • dockerd --mtu=1400
• https://github.com/microsoft/WSL/issues/4698#issuecomment-871279847
• https://serverfault.com/questions/231036