install via source
- curl-config
get
post
put
- send PUT request
delete
- send a DELETE request
authorization
content type
- set the content type for a Curl request
others
convert
12 Essential Curl Commands for Linux, Windows and macOS
references
- Top 20 Curl Flags
- write-out

references:

online rest & soap api testing tool : curl

curl.1 the man page

available %-symbols:
content_type

curl_version

errormsg

exitcode

filename_effective

ftp_entry_path

http_code - The numerical response code that was found in the last retrieved HTTP(S) or FTP(s) transfer

http_connect

http_version

json

local_ip

local_port

method

num_connects

num_headers

num_redirects

proxy_ssl_verify_result

redirect_url

referer

remote_ip

remote_port

response_code - The numerical response code that was found in the last transfer (formerly known as http_code)

scheme

size_download

size_header

size_request

size_upload

speed_download

speed_upload

ssl_verify_result

stderr

stdout

time_appconnect

time_connect

time_namelookup

time_pretransfer

time_redirect

time_starttransfer

time_total

url

url_effective

urlnum
get via
$ curl -sSLg \
       -k \
       -o /dev/null \
       -w "%{json}" \
       https://domain.name.com |
  jq -r 'keys[]' |
  sort

install via source

[!NOTE|label:references:]

Re: Using libcurl to send shell commands through SSH?

libcurl 8

How to Build and Install latest cURL version on CentOS and Ubuntu?

how to install curl and libcurl

release curl/curl

environment

[!TIP]

centos:

gcc : appstream

libssh2 : @epel

libssh2-devel : @epel : $ dnf install libssh2 libssh2-devel libssh2-docs

libssh2-doc : @epel

zlib : @centos-baseos

brotli : @centos-baseos : $ sudo dnf install brotli-devel.i686

libpsl : @centos-baseos

openssl : @centos-baseos

libidn2 : @centos-baseos

$ sudo dnf install -y autoconf automake libtool
$ sudo dnf install -y wget gcc openssl-devel libssh2 libssh2-devel libssh2-docs brotli brotli-devel
# nice to have
$ sudo dnf install -y zstd libzstd libzstd-devel

$ curl -fsSLgk -O https://github.com/curl/curl/releases/download/curl-8_2_1/curl-8.2.1.tar.gz
$ tar xzf curl-8.2.1.tar.gz
$ cd curl-8.2.1

build

[!NOTE|label:references]

--prefix=/usr/local will install in :

/usr/local/lib

/usr/local/bin

/usr/local/include

/usr/local/share

$ ./configure --with-libssh \
              --with-libssh2 \
              --with-ssl \
              --with-wolfssh \
              --with-gssapi \
              --enable-websockets \
              --prefix=/opt/curl \
...

configure: Configured to build curl/libcurl:

  Host setup:       x86_64-pc-linux-gnu
  Install prefix:   /opt/curl
  Compiler:         gcc
   CFLAGS:          -Werror-implicit-function-declaration -O2 -Wno-system-headers -pthread
   CPPFLAGS:
   LDFLAGS:
   LIBS:            -lssh2 -lssh2 -lssl -lcrypto -lssl -lcrypto -lgssapi_krb5 -lzstd -lz

  curl version:     8.2.1
  SSL:              enabled (OpenSSL)
  SSH:              enabled (libSSH2)
  zlib:             enabled
  brotli:           no      (--with-brotli)
  zstd:             enabled (libzstd)
  GSS-API:          enabled (MIT Kerberos/Heimdal)
  GSASL:            no      (libgsasl not found)
  TLS-SRP:          enabled
  resolver:         POSIX threaded
  IPv6:             enabled
  Unix sockets:     enabled
  IDN:              no      (--with-{libidn2,winidn})
  Build libcurl:    Shared=yes, Static=yes
  Built-in manual:  enabled
  --libcurl option: enabled (--disable-libcurl-option)
  Verbose errors:   enabled (--disable-verbose)
  Code coverage:    disabled
  SSPI:             no      (--enable-sspi)
  ca cert bundle:   /etc/pki/tls/certs/ca-bundle.crt
  ca cert path:     no
  ca fallback:      no
  LDAP:             no      (--enable-ldap / --with-ldap-lib / --with-lber-lib)
  LDAPS:            no      (--enable-ldaps)
  RTSP:             enabled
  RTMP:             no      (--with-librtmp)
  PSL:              no      (libpsl not found)
  Alt-svc:          enabled (--disable-alt-svc)
  Headers API:      enabled (--disable-headers-api)
  HSTS:             enabled (--disable-hsts)
  HTTP1:            enabled (internal)
  HTTP2:            no      (--with-nghttp2, --with-hyper)
  HTTP3:            no      (--with-ngtcp2 --with-nghttp3, --with-quiche, --with-msh3)
  ECH:              no      (--enable-ech)
  WebSockets:       enabled
  Protocols:        DICT FILE FTP FTPS GOPHER GOPHERS HTTP HTTPS IMAP IMAPS MQTT POP3 POP3S RTSP SCP SFTP SMB SMBS SMTP SMTPS TELNET TFTP WS WSS
  Features:         AsynchDNS GSS-API HSTS HTTPS-proxy IPv6 Kerberos Largefile NTLM NTLM_WB SPNEGO SSL TLS-SRP UnixSockets alt-svc libz threadsafe zstd

  WARNING:  Websockets enabled but marked EXPERIMENTAL. Use with caution!

$ make -j
$ sudo make install

# check
$ tree -L 2 /opt/curl
/opt/curl
├── bin
│   ├── curl
│   └── curl-config
├── include
│   └── curl
├── lib
│   ├── libcurl.a
│   ├── libcurl.la
│   ├── libcurl.so -> libcurl.so.4.8.0
│   ├── libcurl.so.4 -> libcurl.so.4.8.0
│   ├── libcurl.so.4.8.0
│   └── pkgconfig
└── share
    ├── aclocal
    └── man

full configure

full config

$ ./configure --with-libssh \
              --with-libssh2 \
              --with-ssl \
              --with-openssl \
              --with-zstd \
              --with-wolfssh \
              --with-gnu-ld \
              --with-gssapi \
              --with-zlib \
              --with-brotli \    # ../lib/.libs/libcurl.so: undefined reference to `BrotliDecoderCreateInstance'`
              --with-quiche \
              --with-nghttp3 \
              --with-ngtcp2 \
              --with-libidn2 \
              --with-zsh-functions-dir
              --enable-debug \
              --enable-optimize \
              --enable-warnings \
              --enable-werror \
              --enable-curldebug \
              --enable-http \
              --enable-ftp \
              --enable-file \
              --enable-ldaps \
              --enable-proxy \
              --enable-dict \
              --enable-telnet \
              --enable-tftp \
              --enable-smb \
              --enable-manual \
              --enable-libcurl-option \
              --enable-libgcc \
              --enable-ipv6 \
              --enable-openssl-auto-load-config \
              --enable-verbose \
              --enable-unix-sockets \
              --enable-socketpair \
              --enable-http-auth \
              --enable-netrc \
              --enable-dnsshuffle \
              --enable-websockets \
              --enable-hsts \
              --enable-headers-api \
              --enable-alt-svc \
              --enable-get-easy-options \
              --prefix=/usr/local

  Host setup:       x86_64-pc-linux-gnu
  Install prefix:   /usr/local
  Compiler:         gcc
   CFLAGS:          -Werror-implicit-function-declaration -g -O2 -std=gnu89 -pedantic -Wall -W -Wpointer-arith -Wwrite-strings -Wunused -Wshadow -Winline -Wnested-externs -Wmissing-declarations -Wmissing-prototypes -Wno-long-long -Wbad-function-cast -Wfloat-equal -Wno-multichar -Wsign-compare -Wundef -Wno-format-nonliteral -Wendif-labels -Wstrict-prototypes -Wdeclaration-after-statement -Wold-style-definition -Wstrict-aliasing=3 -Wcast-align -Wtype-limits -Wold-style-declaration -Wmissing-parameter-type -Wempty-body -Wclobbered -Wignored-qualifiers -Wconversion -Wno-sign-conversion -Wvla -ftree-vrp -Wdouble-promotion -Wformat=2 -Warray-bounds=2 -Wshift-negative-value -Wshift-overflow=2 -Wnull-dereference -fdelete-null-pointer-checks -Wduplicated-cond -Wunused-const-variable -Wduplicated-branches -Wrestrict -Walloc-zero -Wformat-overflow=2 -Wformat-truncation=2 -Wimplicit-fallthrough=4 -Wno-system-headers -pthread
   CPPFLAGS:
   LDFLAGS:         -L/usr/lib
   LIBS:            -lssh2 -lssh2 -lssl -lcrypto -lssl -lcrypto -lgssapi_krb5 -lldap -llber -lzstd -lzstd -lz -lgcc

  curl version:     8.2.1
  SSL:              enabled (OpenSSL)
  SSH:              enabled (libSSH2)
  zlib:             enabled
  brotli:           enabled (libbrotlidec)
  zstd:             enabled (libzstd)
  GSS-API:          enabled (MIT Kerberos/Heimdal)
  GSASL:            no      (libgsasl not found)
  TLS-SRP:          enabled
  resolver:         POSIX threaded
  IPv6:             enabled
  Unix sockets:     enabled
  IDN:              no      (--with-{libidn2,winidn})
  Build libcurl:    Shared=yes, Static=yes
  Built-in manual:  enabled
  --libcurl option: enabled (--disable-libcurl-option)
  Verbose errors:   enabled (--disable-verbose)
  Code coverage:    disabled
  SSPI:             no      (--enable-sspi)
  ca cert bundle:   /etc/pki/tls/certs/ca-bundle.crt
  ca cert path:     no
  ca fallback:      no
  LDAP:             enabled (OpenLDAP)
  LDAPS:            enabled
  RTSP:             enabled
  RTMP:             no      (--with-librtmp)
  PSL:              no      (libpsl not found)
  Alt-svc:          enabled (--disable-alt-svc)
  Headers API:      enabled (--disable-headers-api)
  HSTS:             enabled (--disable-hsts)
  HTTP1:            enabled (internal)
  HTTP2:            no      (--with-nghttp2, --with-hyper)
  HTTP3:            no      (--with-ngtcp2 --with-nghttp3, --with-quiche, --with-msh3)
  ECH:              no      (--enable-ech)
  WebSockets:       enabled
  Protocols:        DICT FILE FTP FTPS GOPHER GOPHERS HTTP HTTPS IMAP IMAPS LDAP LDAPS MQTT POP3 POP3S RTSP SCP SFTP SMB SMBS SMTP SMTPS TELNET TFTP WS WSS
  Features:         AsynchDNS GSS-API HSTS HTTPS-proxy IPv6 Kerberos Largefile NTLM NTLM_WB SPNEGO SSL TLS-SRP UnixSockets alt-svc brotli libz threadsafe zstd

  WARNING:  Websockets enabled but marked EXPERIMENTAL. Use with caution!

$ make -j && sudo make install

$ curl --version
WARNING: this libcurl is Debug-enabled, do not use in production

curl 8.2.1 (x86_64-pc-linux-gnu) libcurl/8.2.1 OpenSSL/1.1.1k-fips zlib/1.2.11 zstd/1.4.4 libssh2/1.9.0 OpenLDAP/2.4.46
Release-Date: 2023-07-26
Protocols: dict file ftp ftps gopher gophers http https imap imaps ldap ldaps mqtt pop3 pop3s rtsp scp sftp smb smbs smtp smtps telnet tftp ws wss
Features: alt-svc AsynchDNS Debug GSS-API HSTS HTTPS-proxy IPv6 Kerberos Largefile libz NTLM NTLM_WB SPNEGO SSL threadsafe TLS-SRP TrackMemory UnixSockets zstd

$ curl-config --configure
 '--without-brotli' '--with-quiche' '--with-zstd' '--with-nghttp3' '--with-ngtcp2' '--with-ssl' '--with-gssapi' '--enable-debug' '--enable-optimize' '--enable-warnings' '--enable-werror' '--enable-curldebug' '--enable-http' '--enable-ftp' '--enable-file' '--enable-ldaps' '--enable-proxy' '--enable-dict' '--enable-telnet' '--enable-tftp' '--enable-smb' '--enable-manual' '--enable-libcurl-option' '--enable-libgcc' '--enable-ipv6' '--enable-openssl-auto-load-config' '--enable-verbose' '--enable-unix-sockets' '--enable-socketpair' '--enable-http-auth' '--enable-netrc' '--enable-dnsshuffle' '--enable-websockets' '--enable-hsts' '--enable-headers-api' '--enable-alt-svc' '--enable-get-easy-options' '--with-openssl' '--with-gnu-ld' '--with-zlib' '--with-libssh2' '--with-libssh' '--with-wolfssh' '--with-libidn2' '--with-zsh-functions-dir' '--prefix=/usr/local'

for issue: undefined reference to 'BrotliDecoderCreateInstance':

$ make -j
../lib/.libs/libcurl.so: undefined reference to 'BrotliDecoderCreateInstance'
../lib/.libs/libcurl.so: undefined reference to 'BrotliDecoderVersion'
../lib/.libs/libcurl.so: undefined reference to 'BrotliDecoderDestroyInstance'
../lib/.libs/libcurl.so: undefined reference to 'BrotliDecoderDecompressStream'
../lib/.libs/libcurl.so: undefined reference to 'BrotliDecoderGetErrorCode'
collect2: error: ld returned 1 exit status
make[2]: *** [Makefile:1018: curl] Error 1

solution:
```
$ ./configure --without-brotli ...
```

set

[!NOTE|label:OPTIONAL] no need if using /usr/local as --prefix

$ sudo update-alternatives --install /usr/local/bin/curl curl /opt/curl/bin/curl 999
$ sudo update-alternatives --install /usr/local/bin/curl-config curl-config /opt/curl/bin/curl-config 999

# or /opt/curl
$ bash -c "echo 'export LD_LIBRARY_PATH=/opt/curl/lib:$LD_LIBRARY_PATH' >> /etc/bashrc"
$ bash -c "echo 'export LD_RUN_PATH=/opt/curl/lib:$LD_RUN_PATH' >> /etc/bashrc"

# or /usr/local
$ bash -c "echo 'export LD_LIBRARY_PATH=/usr/local/lib:$LD_LIBRARY_PATH' >> /etc/bashrc"
$ bash -c "echo 'export LD_RUN_PATH=/usr/local/lib:$LD_RUN_PATH' >> /etc/bashrc"

check

$ alternatives --list | grep curl
curl                    auto    /opt/curl/bin/curl
curl-config             auto    /opt/curl/bin/curl-config

$ curl --version
curl 8.2.1 (x86_64-pc-linux-gnu) libcurl/8.2.1 OpenSSL/1.1.1k-fips zlib/1.2.11 zstd/1.4.4 libssh2/1.9.0
Release-Date: 2023-07-26
Protocols: dict file ftp ftps gopher gophers http https imap imaps mqtt pop3 pop3s rtsp scp sftp smb smbs smtp smtps telnet tftp ws wss
Features: alt-svc AsynchDNS GSS-API HSTS HTTPS-proxy IPv6 Kerberos Largefile libz NTLM NTLM_WB SPNEGO SSL threadsafe TLS-SRP UnixSockets zstd

$ curl --help all

curl-config

[!NOTE|label:references:]

curl-config.1 -- man page

$ curl-config --libs
-L/usr/local/Cellar/curl/8.2.1/lib -lcurl

$ curl-config --feature
AsynchDNS
GSS-API
HSTS
HTTP2
HTTPS-proxy
IDN
IPv6
Kerberos
Largefile
MultiSSL
NTLM
NTLM_WB
SPNEGO
SSL
TLS-SRP
UnixSockets
alt-svc
brotli
libz
threadsafe
zstd

$ curl-config --cflags
-I/usr/local/Cellar/curl/8.2.1/include

$ curl-config --configure
 '--disable-debug' '--disable-dependency-tracking' '--disable-silent-rules' '--prefix=/usr/local/Cellar/curl/8.2.1' '--with-ssl=/usr/local/opt/openssl@3' '--without-ca-bundle' '--without-ca-path' '--with-ca-fallback' '--with-secure-transport' '--with-default-ssl-backend=openssl' '--with-libidn2' '--with-librtmp' '--with-libssh2' '--without-libpsl' '--with-gssapi' 'CC=clang'

get

get JSON

$ curl https://reqbin.com/echo/get/json \
       -H "Accept: application/json"

get XML

$ curl https://reqbin.com/echo/get/xml \
       -H "Accept: application/xml"

get `http_code` or `response_code`

$ curl -s -o /dev/null -w "%{http_code}" https://github.com
200

$ curl -s -o /dev/null -w "response: '%{response_code}'" https://github.com
response: '200'

$ curl -sSgL -X GET https://github.com/fake/url | sed -nre 's!^.*"status"\s*:\s*([0-9]+).*$!\1!gp'
404

$ curl http://www.example.org -o >(cat >&1) -w "%{http_code}\n" 1>&2

get `http_code` for multiple urls

$ xargs -n1 curl -sk -o /dev/null -w '%{http_code} ' < <(echo "https://1.domain.com https://2.domain.com")

# i.e.:
$ xargs -n1 curl -sk -o /dev/null -w '%{http_code} ' < <(echo "https://stackoverflow.com/questions/3110444/ https://stackoverflow.com/questions/3110444/")
301 301

$ echo "https://1.domain.com
https://2.domain.com
" > urls.txt
$ xargs -n1 curl -sk -o /dev/null -w '%{http_code} ' < urls.txt

$ curl -sSgL -X GET https://1.domain.com https://2.domain.com | sed -nre 's!^.*"status"\s*:\s*([0-9]+).*$!\1!gp'
404
200

get `size_download`

$ curl -R -s -S -w "\nhttp: %{http_code}. size: %{size_download}\n" -o /dev/null https://github.com

get time

$ curl -s \
       -w 'results: \n
           Lookup time:\t%{time_namelookup}
           Connect time:\t%{time_connect}
           PreXfer time:\t%{time_pretransfer}
           StartXfer time:\t%{time_starttransfer}
           AppCon time:\t%{time_appconnect}
           Redirect time:\t%{time_redirect}\n
           Total time:\t%{time_total}\n' \
       -o /deve/null \
       https://github.com

results:

         Lookup time: 0.001288
         Connect time:  0.001617
         PreXfer time:  0.080264
         StartXfer time:  0.119895
         AppCon time: 0.080165
         Redirect time: 0.000000

         Total time:  0.120600

post

post JSON data using Curl

$ curl -X POST https://reqbin.com/echo/post/json \
       -H 'Content-Type: application/json' \
       -d '{"login":"my_login","password":"my_password"}'

post a file using Curl

$ curl -d @data.json https://reqbin.com/echo/post/json

post form data using Curl

$ curl -X POST https://reqbin.com/echo/post/form \
       -H "Content-Type: application/x-www-form-urlencoded" \
       -d "param1=value1&param2=value2"

post XML

$ curl -X POST https://reqbin.com/echo/post/xml \
       -H "Content-Type: application/xml" \
       -H "Accept: application/xml" \
       -d "<Request><Login>my_login</Login><Password>my_password</Password></Request>"

put

send PUT request

$ curl -X PUT https://reqbin.com/echo/put/json \
       -d "PUT request data"

delete

syntax:

$ curl -X DELETE [URL] [options]

send a DELETE request

$ curl -X DELETE http://reqbin.com/sample/delete/json?id=1 \
       -H "Accept: application/json"

authorization

Basic Auth Credentials

$ curl https://reqbin.com/echo \
       -u "login:password"

Bearer Token Authorization Header

$ curl https://reqbin.com/echo/get/json \
       -H "Accept: application/json" \
       -H "Authorization: Bearer {token}"

Curl with a proxy

$ curl https://reqbin.com/echo \
       -x myproxy.com:8080 \
       -U login:password

content type

set the content type for a Curl request

$ curl -X POST https://reqbin.com/echo/post/json \
       -H 'Content-Type: application/json' \
       -H 'Accept: application/json' \
       -d '{"Id": 78912, "Quantity": 1, "Price": 19.00}'

others

ssl

ignore invalid and self-signed SSL certificate errors in Curl

$ curl -k https://expired.badssl.com

make HTTPS requests with Curl

$ curl -k https://expired.badssl.com

with SSL connections

$ curl -k https://expired.badssl.com

send http header with curl request

$ curl https://reqbin.com/echo/get/json \
       -H "X-Custom-Header: value" \
       -H "Content-Type: application/json"

set a timeout

$ curl --connection-timeout 5 https://reqbin.com/echo

send a head request

$ curl -I https://reqbin.com/echo

send a OPTIONS request

$ curl https://api.reqbin.com/api/v1/requests \
       -X OPTIONS  \
       -H "Access-Control-Request-Method: POST" \
       -H "Access-Control-Request-Headers: content-type" \
       -H "Origin: https://reqbin.com"

send a CORS request

$ curl -H "Origin: https://example.reqbin.com" \
       https://reqbin.com/echo

send Cookies

$ curl --cookie "Name=Value" https://reqbin.com/echo

set the User-Agent string

$ curl https://reqbin.com/echo \
       -A "ReqBin Curl Client/1.0"

watch web server returns

$ watch -n 15 curl -s --connect-timeout 10 http://www.google.com/

convert

convert to python requests

$ curl -X POST https://reqbin.com/echo/post/json \
       -H "Content-Type: application/json" \
       -d "{\"login\":\"my_login\",\"password\":\"my_password\"}"

convert to javascript/ajax calls

$ curl -X POST https://reqbin.com/echo/post/json \
       -H "Content-Type: application/json" \
       -d "{\"login\":\"my_login\",\"password\":\"my_password\"}"

convert to php code

$ curl -X POST https://reqbin.com/echo/post/json \
       -H "Content-Type: application/json" \
       -d "{\"login\":\"my_login\",\"password\":\"my_password\"}"

convert to http request

$ curl https://reqbin.com/echo/get/json \
       -H "Content-Type: application/json" \
       -H "Accept: application/json"

12 Essential Curl Commands for Linux, Windows and macOS

get resource content by url
```
$ curl https://reqbin.com/echo
```

save url content to a file

$ curl -o logo.png https://reqbin.com/static/img/logo.png

download multiple files at once

$ curl -O https://reqbin.com/static/img/code/curl.png \
       -O https://reqbin.com/static/img/code/java.png \
       -O https://reqbin.com/static/img/code/python.png

check page http headers bash
force curl to use http/2 protocol
```
$ curl --http2 https://reqbin.com
```
do follow redirects
```
$ curl -L http://www.reqbin.com/echo
```

use proxy server

$ curl -x proxy.domain.com:8080 -U user:password https://reqbin.com

provide additional http headers with request

$ curl -H "Accept: application/json" https://reqbin.com/echo/get/json

send data to the server

$ curl -d '{"id": 123456}' \
       -H "Content-Type: application/json" \
       https://reqbin.com/echo/post/json

change the user-agent string

$ curl --user-agent "MyAppName 1.0" https://reqbin.com/echo

send cookies to website

$ curl -b "name1=value1; name2=value2" https://reqbin.com

references

Top 20 Curl Flags

Flags	Description	Syntax
`-O`	Download the file and save it under the original name	`curl -O [URL]`
`-o`	Download the file and save it with a different name	`curl -o [file name] [URL]`
`-X`	Specify the HTTP method to be used when sending the request	`curl -X [method] [URL]`
`-I or -head`	Print the title without the body of the document	`curl -I [URL]`
`-d`	Specify the data to send to the server	`curl -d "key1=value1&key2=value2" [URL]`
`-k or -insecure`	Ignore SSL Certificate Errors	`curl -k [URL]`
`-u or --user`	Specify the authentication data by passing a pair of login-password	`curl -u [user:password] [URL]`
`-F`	Submit form data as POST request	`curl -F @field_name=@path/to/myFile`
`--cookie`	Send HTTP cookies	`curl --cookie "Name=Value" [URL]`
`-x or --proxy`	Use a proxy server to upload files	`curl -x "[protocol://][host][:port]" [URL] [options]`
`--limit-rate`	Limit the download speed	`curl --limit-rate [speed] -O [URL]`
`-L or --location`	Follow Curl redirect using HTTP Location header	`curl -L [URL]`
`-v`	Makes Curl verbose	`curl -v [URL]`
`-m or --max-time`	Set a limit in seconds for the entire operation	`curl -m [SECONDS] [URL]`
`--connect-timeout`	Set a limit in seconds for a connection request	`curl --connect-timeout [SECONDS] [URL]`
`-T`	Transfers the specified local file to a remote URL	`curl -T [file name] [URL]`
`-H or --header`	Add additional HTTP request header	`curl -H "X-Header: value" [URL]`
`-D`	Save the HTTP headers that the site sends back	`curl -D [URL]`
`-A or --user-agent`	Set User-Agent string	`curl -A "value" [URL]`
`-C`	Resume an interrupted or intentionally stopped download	`curl -C [OFFSET] -O [URL]`

write-out

Option	Description
Lookup time (`time_namelookup`)	The time, in seconds, it took from the start until the name resolving was completed
Connect time (`time_connect`)	The time, in seconds, it took from the start until the TCP connect to the remote host was completed
PreXfer time (`time_pretransfer`)	The time, in seconds, it took from the start until the file transfer was just about to begin. This includes all ‘pre-transfer’ commands and negotiations that are specific to the particular protocol(s) involved
StartXfer time (`time_starttransfer`)	The time, in seconds, it took from the start until the first byte was just about to be transferred. This includes ‘time_pretransfer’ and also the time the server needed to calculate the result
AppCon time (`time_appconnect`)	The time, in seconds, it took from the start until the SSL/SSH/etc connect/handshake to the remote host was completed (Added in 7.19.0)
Redirect time (`time_redirect`)	The time, in seconds, it took for all redirection steps include name lookup, connect, pretransfer and transfer before the final transaction was started. ‘time_redirect’ shows the complete execution time for multiple redirections. (Added in 7.12.3)