cURL / Mailing Lists / curl-library / Single Mail


Re: libcurl buffer for SFTP

From: Daniel Stenberg <>
Date: Thu, 10 Dec 2015 04:40:31 +0100 (CET)

On Mon, 7 Dec 2015, Vrajesh N. Patel via curl-library wrote:

> The blog post described altering the buffer size from the default 16k. I
> would prefer to alter the buffer size for only SFTP uploads but I need a bit
> of help figuring out which file/function to alter. If I were to make the
> fix and rebuild the library, would I make the fix in lib/ssh.c?

You tell us. Part of the suggested job involves figuring out or suggesting an
approach. Perhaps that means allocating the buffer of a certain size once you
learn which protocol is to be used?

> The easier change to make is to set CURL_MAX_WRITE_SIZE to 512k

Certainly, but we will not accept an unconditional change like that back to
the code repo.

> but I'm not sure if anyone experienced adverse effects when doing FTP
> transfers (upload or download) on a Linux platform with that large of a
> buffer?

The downside is that you spend a half of a megabyte for each handle, and if
you have hundreds or thousands of handles, you run out of memory quite

List admin:
Received on 2015-12-10