Home/ Questions/Q 7548767
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-30T09:46:54+00:00

I’m making an HTTP POST request using curl like this: curl -v -i -d

  • 0

I’m making an HTTP POST request using curl like this:

curl -v -i -d 'var=something' 'http://mysite.com/whatever.json'

How can I see the body of the outgoing request?

Motivation: I’m debugging an Objective-C HTTP library. POST requests that are failing in this library are working from the Terminal using curl. I think comparing the bodies of the requests will help debug.

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    You can use --trace or --trace-ascii to get an traffic dump:

    curl --trace - -d 'var=something' 'http://mysite.com/whatever.json'
[...]
=> Send header, 246 bytes (0xf6)
0000: 50 4f 53 54 20 2f 77 68 61 74 65 76 65 72 2e 6a POST /whatever.j
0010: 73 6f 6e 20 48 54 54 50 2f 31 2e 31 0d 0a 55 73 son HTTP/1.1..Us
0020: 65 72 2d 41 67 65 6e 74 3a 20 63 75 72 6c 2f 37 er-Agent: curl/7
0030: 2e 32 31 2e 36 20 28 78 38 36 5f 36 34 2d 70 63 .21.6 (x86_64-pc
0040: 2d 6c 69 6e 75 78 2d 67 6e 75 29 20 6c 69 62 63 -linux-gnu) libc
0050: 75 72 6c 2f 37 2e 32 31 2e 36 20 4f 70 65 6e 53 url/7.21.6 OpenS
0060: 53 4c 2f 31 2e 30 2e 30 65 20 7a 6c 69 62 2f 31 SL/1.0.0e zlib/1
0070: 2e 32 2e 33 2e 34 20 6c 69 62 69 64 6e 2f 31 2e .2.3.4 libidn/1.
0080: 32 32 20 6c 69 62 72 74 6d 70 2f 32 2e 33 0d 0a 22 librtmp/2.3..
0090: 48 6f 73 74 3a 20 6d 79 73 69 74 65 2e 63 6f 6d Host: mysite.com
00a0: 0d 0a 41 63 63 65 70 74 3a 20 2a 2f 2a 0d 0a 43 ..Accept: */*..C
00b0: 6f 6e 74 65 6e 74 2d 4c 65 6e 67 74 68 3a 20 31 ontent-Length: 1
00c0: 33 0d 0a 43 6f 6e 74 65 6e 74 2d 54 79 70 65 3a 3..Content-Type:
00d0: 20 61 70 70 6c 69 63 61 74 69 6f 6e 2f 78 2d 77  application/x-w
00e0: 77 77 2d 66 6f 72 6d 2d 75 72 6c 65 6e 63 6f 64 ww-form-urlencod
00f0: 65 64 0d 0a 0d 0a                               ed....
=> Send data, 13 bytes (0xd)
0000: 76 61 72 3d 73 6f 6d 65 74 68 69 6e 67          var=something
[...]

    --trace-ascii has less detail:

    curl --trace-ascii - -d 'var=something' 'http://mysite.com/whatever.json'
[...]
=> Send header, 246 bytes (0xf6)
0000: POST /whatever.json HTTP/1.1
001e: User-Agent: curl/7.21.6 (x86_64-pc-linux-gnu) libcurl/7.21.6 Ope
005e: nSSL/1.0.0e zlib/1.2.3.4 libidn/1.22 librtmp/2.3
0090: Host: mysite.com
00a2: Accept: */*
00af: Content-Length: 13
00c3: Content-Type: application/x-www-form-urlencoded
00f4: 
=> Send data, 13 bytes (0xd)
0000: var=something
[...]
    • 0