This is the second day of my participation in Gwen Challenge

Introduction to the

Normally, we access an interface or link in one of the following ways:

  1. Browser access
  2. HTTP tool access (POSTman/IDEA HTTP client, etc.)
  3. Curl (access from the command line)

CURL is a file transfer tool that works on the command line using URL syntax. CURL was first released in 1997. CURL is a download tool that supports both uploading and downloading files. CURL also includes libcurl for program development.

The only thing I can remember is curl ‘http://xxxx’, and the corresponding parameter meaning of baidu every time. I can’t fake it if I’m around my colleagues. Let’s record a wave.

Let’s start with a summary chart (From zhihu)

Begin to use

Curl is also a directive for Linux. You can view the parameters with help (complete in Appendix 1).

A request is a combination of commands and parameters. The following is a very simple request

Curl -v 'www.baidu.com' # returned contents * peopleurl to: www.baidu.com/ * Trying 103.235.46.39... * Connected to www.baidu.com (103.235.46.39) port 80 (#0) > GET/HTTP/1.1 > Host: www.baidu.com > user-agent: Curl /7.47.0 > Accept: */* > < < HTTP/1.1 200 OK < accept-ranges: bytes < cache-control: private, no-cache, no-store, proxy-revalidate, no-transform < Connection: keep-alive < Content-Length: 2381 < Content-Type: text/html < Date: Sun, 13 Jun 2021 17:15:41 GMT < Etag: "588604ec-94d" < Last-Modified: Mon, 23 Jan 2017 13:28:12 GMT < Pragma: no-cache < Server: BFE /1.0.8.18 < set-cookie: BDORZ=27315; max-age=86400; domain=.baidu.com; path=/ < <! DOCTYPE html> <! --STATUS OK--><html> <head><meta http-equiv=content-type content=text/html; charset=utf-8><meta http-equiv=X-UA-Compatible content=IE=Edge><meta content=always name=referrer><link rel=stylesheet Type = "text/CSS href=http://s1.bdstatic.com/r/www/cache/bdorz/baidu.min.css > < title > baidu once, </title></head> <body link=#0000cc> <div id=wrapper> <div id=head> <div class=head_wrapper> <div class=s_form> <div class=s_form_wrapper> <div id=lg> <img hidefocus=true src=//www.baidu.com/img/bd_logo1.png width=270 height=129> </div> <form id=form name=f action=//www.baidu.com/s class=fm> <input type=hidden name=bdorz_come value=1> <input type=hidden name=ie value=utf-8> <input type=hidden name=f value=8> <input type=hidden name=rsv_bp value=1> <input type=hidden name=rsv_idx value=1> <input type=hidden name=tn value=baidu><span class="bg s_ipt_wr"><input id=kw name=wd class=s_ipt Value maxlength=255 autocomplete=off autofocus></span><span class="bg s_btn_wr">< form type=submit ID =su value= class="bg s_btn"></span> </form> </div> </div> <div id=u1> <a href=http://news.baidu.com name=tj_trnews Class =mnav> news </a> <a href=http://www.hao123.com name=tj_trhao123 class=mnav>hao123</a> <a href=http://map.baidu.com Name =tj_trmap class=mnav> map </a> <a href=http://v.baidu.com name=tj_trvideo class=mnav> Video </a> <a Href =http://tieba.baidu.com name=tj_trtieba class=mnav> </a> <noscript> <a href=http://www.baidu.com/bdorz/login.gif?login&amp; tpl=mn&amp; U = HTTP %3A%2F%2Fwww.baidu.com% 2F% 3fbdorz_come%3d1 Name =tj_login class=lb> login </a> </noscript> <script>document.write('<a href="http://www.baidu.com/bdorz/login.gif?login&tpl=mn&u='+ encodeURIComponent(window.location.href+ (window. The location. The search = = = ""??" ":" & ") + "bdorz_come = 1") + 'tj_login "name =" "class =" lb "> login < / a >'); </script> <a href=//www.baidu.com/more/ name=tj_briicon class=bri style="display: block;" </a> </div> </div> <div id=ftCon> <div id=ftConw> <p id=lh> <a href=http://home.baidu.com href=http://ir.baidu.com>About Baidu</a> </p> <p id=cp>&copy; 2017&nbsp; Baidu&nbsp; < a href=http://www.baidu.com/duty/ > before using baidu required < / a > & have spent <a href=http://jianyi.baidu.com/ class=cp-feedback> </a>&nbsp; Beijing ICP Certificate 030173 & NBSP; <img src=//www.baidu.com/img/gs.gif> </p> </div> </div> </div> </body> </html> * Connection #0 to host www.baidu.com left intactCopy the code

Common parameters

Parameter (case sensitive) Extended writing note
-X –request The request mode, if not specified, is GET
-d –data Request parameters, followed by text or file path

If you need urlencode, you can use it--data-urlencode
-H –header Request headers (multiple request headers used multiple times-H)
-b –cookie Request cookie, followed by text or file path
-i –include View the response header
-I –head The return value takes only the response header
-v –verbose Output detailed return information, usually used for DEBUGGING
-O –remote-name External file output to file
-o –output Output to file
-u –user Account PASSWORD USER[:PASSWORD]

Some instructions that might be used

#Make a get requestThe curl 'http://127.0.0.1:8080/user'
#Send the POST JSON formatcurl -v -X POST -H "Content-Type: Application/json "http://127.0.0.1:8080/user - d '{" username" : "admin", "password" : "admin1234"}'
## Send post X-www-form-urlencodedCurl -v - X POST - data - urlencode 'key1 = value1 & key2 = value2' http://127.0.0.1:8080/user
## curl certification
curl -u user:pwd URL
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Keeping the above in mind should be sufficient for daily use of (B)

conclusion

Curl is a Linux command that can be used to request or access web addresses on a Linux machine.

In the browser, we can also copy the request to curl format.

The Http Client tool of IDEA also supports the conversion of curl to the corresponding format request.

The appendix

1. Refer to the article

  1. The public – Java3y
  2. Using the curl command

2. curl –help

Usage: curl [options...] <url>
Options: (H) means HTTP/HTTPS only, (F) means FTP only
     --anyauth       Pick "any" authentication method (H)
 -a, --append        Append to target file when uploading (F/SFTP)
     --basic         Use HTTP Basic Authentication (H)
     --cacert FILE   CA certificate to verify peer against (SSL)
     --capath DIR    CA directory to verify peer against (SSL)
 -E, --cert CERT[:PASSWD]  Client certificate file and password (SSL)
     --cert-status   Verify the status of the server certificate (SSL)
     --cert-type TYPE  Certificate file type (DER/PEM/ENG) (SSL)
     --ciphers LIST  SSL ciphers to use (SSL)
     --compressed    Request compressed response (using deflate or gzip)
 -K, --config FILE   Read config from FILE
     --connect-timeout SECONDS  Maximum time allowed for connection
 -C, --continue-at OFFSET  Resumed transfer OFFSET
 -b, --cookie STRING/FILE  Read cookies from STRING/FILE (H)
 -c, --cookie-jar FILE  Write cookies to FILE after operation (H)
     --create-dirs   Create necessary local directory hierarchy
     --crlf          Convert LF to CRLF in upload
     --crlfile FILE  Get a CRL list in PEM format from the given file
 -d, --data DATA     HTTP POST data (H)
     --data-raw DATA  HTTP POST data, '@' allowed (H)
     --data-ascii DATA  HTTP POST ASCII data (H)
     --data-binary DATA  HTTP POST binary data (H)
     --data-urlencode DATA  HTTP POST data url encoded (H)
     --delegation STRING  GSS-API delegation permission
     --digest        Use HTTP Digest Authentication (H)
     --disable-eprt  Inhibit using EPRT or LPRT (F)
     --disable-epsv  Inhibit using EPSV (F)
     --dns-servers   DNS server addrs to use: 1.1.1.1;2.2.2.2
     --dns-interface  Interface to use for DNS requests
     --dns-ipv4-addr  IPv4 address to use for DNS requests, dot notation
     --dns-ipv6-addr  IPv6 address to use for DNS requests, dot notation
 -D, --dump-header FILE  Write the headers to FILE
     --egd-file FILE  EGD socket path for random data (SSL)
     --engine ENGINE  Crypto engine (use "--engine list" for list) (SSL)
     --expect100-timeout SECONDS How long to wait for 100-continue (H)
 -f, --fail          Fail silently (no output at all) on HTTP errors (H)
     --false-start   Enable TLS False Start.
 -F, --form CONTENT  Specify HTTP multipart POST data (H)
     --form-string STRING  Specify HTTP multipart POST data (H)
     --ftp-account DATA  Account data string (F)
     --ftp-alternative-to-user COMMAND  String to replace "USER [name]" (F)
     --ftp-create-dirs  Create the remote dirs if not present (F)
     --ftp-method [MULTICWD/NOCWD/SINGLECWD]  Control CWD usage (F)
     --ftp-pasv      Use PASV/EPSV instead of PORT (F)
 -P, --ftp-port ADR  Use PORT with given address instead of PASV (F)
     --ftp-skip-pasv-ip  Skip the IP address for PASV (F)
     --ftp-pret      Send PRET before PASV (for drftpd) (F)
     --ftp-ssl-ccc   Send CCC after authenticating (F)
     --ftp-ssl-ccc-mode ACTIVE/PASSIVE  Set CCC mode (F)
     --ftp-ssl-control  Require SSL/TLS for FTP login, clear for transfer (F)
 -G, --get           Send the -d data with a HTTP GET (H)
 -g, --globoff       Disable URL sequences and ranges using {} and []
 -H, --header LINE   Pass custom header LINE to server (H)
 -I, --head          Show document info only
 -h, --help          This help text
     --hostpubmd5 MD5  Hex-encoded MD5 string of the host public key. (SSH)
 -0, --http1.0       Use HTTP 1.0 (H)
     --http1.1       Use HTTP 1.1 (H)
     --http2         Use HTTP 2 (H)
     --ignore-content-length  Ignore the HTTP Content-Length header
 -i, --include       Include protocol headers in the output (H/F)
 -k, --insecure      Allow connections to SSL sites without certs (H)
     --interface INTERFACE  Use network INTERFACE (or address)
 -4, --ipv4          Resolve name to IPv4 address
 -6, --ipv6          Resolve name to IPv6 address
 -j, --junk-session-cookies  Ignore session cookies read from file (H)
     --keepalive-time SECONDS  Wait SECONDS between keepalive probes
     --key KEY       Private key file name (SSL/SSH)
     --key-type TYPE  Private key file type (DER/PEM/ENG) (SSL)
     --krb LEVEL     Enable Kerberos with security LEVEL (F)
     --libcurl FILE  Dump libcurl equivalent code of this command line
     --limit-rate RATE  Limit transfer speed to RATE
 -l, --list-only     List only mode (F/POP3)
     --local-port RANGE  Force use of RANGE for local port numbers
 -L, --location      Follow redirects (H)
     --location-trusted  Like '--location', and send auth to other hosts (H)
     --login-options OPTIONS  Server login options (IMAP, POP3, SMTP)
 -M, --manual        Display the full manual
     --mail-from FROM  Mail from this address (SMTP)
     --mail-rcpt TO  Mail to this/these addresses (SMTP)
     --mail-auth AUTH  Originator address of the original email (SMTP)
     --max-filesize BYTES  Maximum file size to download (H/F)
     --max-redirs NUM  Maximum number of redirects allowed (H)
 -m, --max-time SECONDS  Maximum time allowed for the transfer
     --metalink      Process given URLs as metalink XML file
     --negotiate     Use HTTP Negotiate (SPNEGO) authentication (H)
 -n, --netrc         Must read .netrc for user name and password
     --netrc-optional  Use either .netrc or URL; overrides -n
     --netrc-file FILE  Specify FILE for netrc
 -:, --next          Allows the following URL to use a separate set of options
     --no-alpn       Disable the ALPN TLS extension (H)
 -N, --no-buffer     Disable buffering of the output stream
     --no-keepalive  Disable keepalive use on the connection
     --no-npn        Disable the NPN TLS extension (H)
     --no-sessionid  Disable SSL session-ID reusing (SSL)
     --noproxy       List of hosts which do not use proxy
     --ntlm          Use HTTP NTLM authentication (H)
     --oauth2-bearer TOKEN  OAuth 2 Bearer Token (IMAP, POP3, SMTP)
 -o, --output FILE   Write to FILE instead of stdout
     --pass PASS     Pass phrase for the private key (SSL/SSH)
     --path-as-is    Do not squash .. sequences in URL path
     --pinnedpubkey FILE/HASHES Public key to verify peer against (SSL)
     --post301       Do not switch to GET after following a 301 redirect (H)
     --post302       Do not switch to GET after following a 302 redirect (H)
     --post303       Do not switch to GET after following a 303 redirect (H)
- #, --progress-bar Display transfer progress as a progress bar--proto PROTOCOLS Enable/disable PROTOCOLS --proto-default PROTOCOL Use PROTOCOL for any URL missing a scheme --proto-redir PROTOCOLS Enable/disable PROTOCOLS on redirect -x, --proxy [PROTOCOL://]HOST[:PORT] Use proxy on given port --proxy-anyauth Pick "any" proxy authentication method (H) --proxy-basic Use Basic authentication on the proxy (H) --proxy-digest Use Digest authentication on the proxy (H) --proxy-negotiate Use HTTP Negotiate (SPNEGO) authentication on the proxy (H) --proxy-ntlm Use NTLM authentication on the proxy (H) --proxy-service-name NAME SPNEGO proxy service name --service-name NAME SPNEGO service name -U, --proxy-user user [:PASSWORD] proxy user and PASSWORD --proxy1.0 HOST[:PORT] Use HTTP/1.0 proxy on given PORT -p, --proxytunnel Operate through a HTTP proxy tunnel (using CONNECT) --pubkey KEY Public key file name (SSH) -Q, --quote CMD Send command(s) to server before transfer (F/SFTP) --random-file FILE File for reading random data from (SSL) -r, --range RANGE Retrieve only the bytes within RANGE --raw Do HTTP "raw"; no transfer decoding (H) -e, --referer Referer URL (H) -J, --remote-header-name Use the header-provided filename (H) -O, --remote-name Write output to a file named as the remote file --remote-name-all Use the remote file name for all URLs -R, --remote-time Set the remote file's time on the local output -X, --request COMMAND Specify request command to use --resolve HOST:PORT:ADDRESS Force resolve of HOST:PORT to ADDRESS --retry NUM Retry request NUM times if transient problems occur --retry-delay SECONDS Wait SECONDS between retries --retry-max-time SECONDS Retry only within this period --sasl-ir Enable initial response in SASL authentication -S, --show-error Show error. With -s, make curl show errors when they occur -s, --silent Silent mode (don't output anything) --socks4 HOST[:PORT] SOCKS4 proxy on given host + port --socks4a HOST[:PORT] SOCKS4a proxy on given host + port --socks5 HOST[:PORT] SOCKS5 proxy on given host + port --socks5-hostname HOST[:PORT] SOCKS5 proxy, pass host name to proxy --socks5-gssapi-service NAME SOCKS5 proxy service name for GSS-API --socks5-gssapi-nec Compatibility with NEC SOCKS5 server -Y, --speed-limit RATE Stop transfers below RATE for 'speed-time' secs -y, --speed-time SECONDS Trigger 'speed-limit' abort after SECONDS (default: 30) --ssl Try SSL/TLS (FTP, IMAP, POP3, SMTP) --ssl-reqd Require SSL/TLS (FTP, IMAP, POP3, SMTP) -2, --sslv2 Use SSLv2 (SSL) -3, --sslv3 Use SSLv3 (SSL) --ssl-allow-beast Allow security flaw to improve interop (SSL) --ssl-no-revoke Disable cert revocation checks (WinSSL) --stderr FILE Where to redirect stderr (use "-" for stdout) --tcp-nodelay Use the TCP_NODELAY  option -t, --telnet-option OPT=VAL Set telnet option --tftp-blksize VALUE Set TFTP BLKSIZE option (must be >512) -z, --time-cond TIME Transfer based on a time condition -1, --tlsv1 Use >= TLSv1 (SSL) --tlsv1.0 Use TLsv1.0 (SSL) --tlsv1.1 Use tlsv1.1 (SSL) --tlsv1.2 Use tlsv1.2 (SSL) --trace FILE Write a debug trace to FILE --trace-ascii FILE Like --trace, but without hex output --trace-time Add time stamps to trace/verbose output --tr-encoding Request compressed transfer encoding (H) -T, --upload-file FILE Transfer FILE to destination --url URL URL to work with -B, --use-ascii Use ASCII/text transfer -u, --user USER[:PASSWORD] Server user and password --tlsuser USER TLS username --tlspassword STRING TLS password --tlsauthtype STRING TLS authentication type (default: SRP) --unix-socket FILE Connect through this Unix domain socket -A, --user-agent STRING Send User-Agent STRING to server (H) -v, --verbose Make the operation more talkative -V, --version Show version number and quit -w, --write-out FORMAT Use output FORMAT after completion --xattr Store metadata in extended file attributes -q Disable .curlrc (must be first parameter)Copy the code