Penggunaan Dasar

Request Sederhana

curl https://example.com          # GET request
curl -o file.html https://url     # save to file
curl -O https://url/file.tar.gz   # save with remote name
curl -L https://url               # follow redirects

Flag Umum

-s	Mode silent (tanpa progress)
-S	Tampilkan error dalam mode silent
-f	Gagal diam-diam pada error HTTP
-L	Ikuti redirect
-o file	Tulis output ke file
-O	Simpan dengan nama file remote
-C -	Lanjutkan unduhan yang terputus
--max-time 30	Timeout setelah 30 detik

HTTP Method

GET & HEAD

curl https://api.example.com/users
curl -I https://example.com       # HEAD (headers only)
curl -i https://example.com       # include response headers

POST

curl -X POST https://api.example.com/users \ -H "Content-Type: application/json" \ -d '{"name":"Jo","email":"[email protected]"}'

PUT & PATCH & DELETE

curl -X PUT https://api.example.com/users/1 \ -d '{"name":"Updated"}' curl -X PATCH https://api.example.com/users/1 \ -d '{"email":"[email protected]"}' curl -X DELETE https://api.example.com/users/1

Header

Mengatur Header

curl -H "Content-Type: application/json" URL
curl -H "Accept: text/html" URL
curl -H "X-Custom: value" URL
curl -H "Header1: v1" -H "Header2: v2" URL

Header Response

-i	Sertakan header response dalam output
-I	Ambil header saja (HEAD)
-D file	Dump header response ke file
-w '%{http_code}'	Cetak HTTP status code

Autentikasi

Basic & Token Auth

curl -u user:pass https://api.example.com
curl -H "Authorization: Bearer TOKEN" URL
curl -u user:pass --digest URL
curl --negotiate -u : URL   # Kerberos/SPNEGO

Metode Auth

-u user:pass	Autentikasi Basic
--digest	HTTP Digest auth
--negotiate	Kerberos/SPNEGO auth
--ntlm	Autentikasi NTLM
-n	Gunakan kredensial ~/.netrc

Data & Form

Mengirim Data

curl -d "key=val&key2=val2" URL   # form urlencoded
curl -d @data.json URL            # data from file
curl --data-raw '{"raw":"json"}' URL
curl --data-urlencode "q=hello world" URL

Upload File

curl -F "[email protected]" URL curl -F "[email protected];type=application/pdf" URL curl -F "field=value" -F "[email protected]" URL

Multipart vs URL-Encoded

-d	application/x-www-form-urlencoded
-F	multipart/form-data
--json	Shorthand: set Content-Type + Accept ke JSON
-T file	Upload file via PUT

SSL/TLS

Opsi Sertifikat

curl --cacert ca.pem URL          # custom CA bundle
curl --cert client.pem URL        # client certificate
curl --cert client.pem --key key.pem URL
curl -k URL                       # skip TLS verify (dev only)

Flag TLS

-k / --insecure	Lewati verifikasi sertifikat TLS
--cacert file	Gunakan CA sertifikat kustom
--cert file	Sertifikat client
--key file	Private key client
--tlsv1.2	Paksa minimum TLS 1.2
--tlsv1.3	Paksa minimum TLS 1.3

Output & Debugging

Verbose & Trace

curl -v URL                       # verbose output
curl --trace dump.txt URL         # full trace to file
curl --trace-ascii - URL          # trace to stdout
curl -w "\n%{http_code}\n" URL    # custom output format

Variabel Write-Out

%{http_code}	HTTP response status code
%{time_total}	Total waktu dalam detik
%{time_connect}	Waktu untuk membuat koneksi
%{size_download}	Byte yang diunduh
%{speed_download}	Kecepatan unduhan rata-rata
%{redirect_url}	URL redirect (jika ada)
%{ssl_verify_result}	Hasil verifikasi SSL (0 = OK)

Contoh Write-Out

curl -s -o /dev/null -w \
  "code: %{http_code}\ntime: %{time_total}s\n" \
  https://example.com

Pola Umum

Alur Kerja API

# GET JSON and pipe to jq
curl -s https://api.example.com/data | jq '.items[]'
# POST JSON with auth
curl -s -H "Authorization: Bearer $TOKEN" \
  --json '{"key":"val"}' https://api.example.com

Pola Unduhan

# Download with progress bar
curl -# -O https://releases.example.com/v2.tar.gz
# Resume interrupted download
curl -C - -O https://releases.example.com/v2.tar.gz
# Download multiple files
curl -O https://url/file1 -O https://url/file2

Helper Scripting

# Check if URL is reachable
curl -sf -o /dev/null https://example.com && echo OK
# Save cookies and reuse
curl -c cookies.txt -b cookies.txt URL
# Rate-limit request
curl --limit-rate 100k URL

Proxy & Jaringan

Pengaturan Proxy

curl -x http://proxy:8080 URL
curl -x socks5://proxy:1080 URL
curl --proxy-user user:pass -x http://proxy:8080 URL
curl --noproxy "*.local,localhost" URL

DNS & Resolve

--resolve host:port:addr	Paksa resolusi DNS ke addr
--dns-servers 8.8.8.8	Gunakan server DNS kustom
--interface eth0	Gunakan interface jaringan tertentu
-4 / -6	Paksa IPv4 / IPv6

Konfigurasi & Lanjutan

File Konfigurasi

# ~/.curlrc — default options
--silent
--location
--max-time 30

# Use config file explicitly
curl -K myconfig.txt URL

Flag Berguna

--retry 3	Coba ulang pada error transien
--retry-delay 2	Jeda antar percobaan ulang (detik)
--compressed	Minta dan dekompresi gzip/br
--limit-rate 100k	Throttle kecepatan transfer
-Z	Transfer paralel (curl 7.66+)
--create-dirs	Buat direktori path untuk -o

REFERENSI CEPAT CURL