Cfxtrjtrk

I need to download files from a sftp server. Unfortunately, the curl version in Ubuntu

7.58.0-2ubuntu3.6 amd64

does not support sftp.

I get the error message

Protocol "sftp" not supported or disabled in libcurl

when trying to download a file. I therefore want to build curl from source to allow sftp. How do I achieve that?

Note: Installing software from a third-party source is a safety risk. Make sure you trust the sources before following these steps.

First, you'll need libssh installed.

You'll need a tarball, e.g.

https://www.libssh2.org/download/libssh2-1.8.2.tar.gz

Extact and install it via:

cd libssh2-1.8.1

./configure

make

sudo make install

Secondly, make sure to uninstall your existing curl:

sudo apt purge curl

I have read that it is also recommended to uninstall the curl libs, e.g. libcurl3-gnutls, BUT I noticed that it has many dependencies I did not want to lose, so I kept it. So be careful about the uninstallation process.

And third, in order to build curl from the sources, clone the curl project:

$ git clone https://github.com/curl/curl.git

That repository contains a GIT-INFO file with useful information on how to build it and it may be useful to have a look into it, as the process may change in the future.

What worked for me was to build it via:

./buildconf

./configure

./configure --disable-libcurl-option --disable-shared --with-libssh2=/usr/local 

make

sudo make install

(curl supports uninstallation via sudo make uninstall. Useful if you having problems or what to try out different flags.)

I didn't use shared libraries as I noticed that curl was having problems finding certain curl-own commands and failed when tryin to run it, e.g. I saw errors like:

curl: symbol lookup error: curl: undefined symbol: curl_url_cleanup

curl: error while loading shared libraries: libcurl.so.4: cannot open shared object file: No such file or directory

Yet with the above mentioned approach I have now a working curl supporting sftp, since sftp shows up within the supported protocols:

$ curl -V

curl 7.64.1-DEV (x86_64-pc-linux-gnu) libcurl/7.64.1-DEV OpenSSL/1.1.0g zlib/1.2.11 libssh2/1.8.1

Release-Date: [unreleased]

Protocols: dict file ftp ftps gopher http https imap imaps pop3 pop3s rtsp scp sftp smb smbs smtp smtps telnet tftp 

Features: AsynchDNS HTTPS-proxy IPv6 Largefile libz NTLM NTLM_WB SSL TLS-SRP UnixSockets

and I can confirm that it downloads file from sftp servers.

Sources: I found about the necessary steps via:

• https://curl.haxx.se/docs/install.html


• http://andrewberls.com/blog/post/adding-sftp-support-to-curl


• http://d.hatena.ne.jp/shammer/20161110/p1