Beyond Linux® From Scratch (systemd Edition) - Version r12.4-495

Chapter 17. Networking Libraries

cURL-8.17.0

Introduction to cURL

The cURL package contains a utility and a library used for transferring files with URL syntax to any of the following protocols: DICT, FILE, FTP, FTPS, GOPHER, GOPHERS, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS, MQTT, POP3, POP3S, RTSP, SMB, SMBS, SMTP, SMPTS, TELNET, and TFTP. Its ability to both download and upload files can be incorporated into other programs to support functions like streaming media.

[Note]

Note

Development versions of BLFS may not build or run some packages properly if LFS or dependencies have been updated since the most recent stable versions of the books.

Package Information

  • Download (HTTP): https://curl.se/download/curl-8.17.0.tar.xz

  • Download MD5 sum: 7a9d4b772fc56d68479b0416f234105a

  • Download size: 2.7 MB

  • Estimated disk space required: 49 MB (add 64 MB for tests)

  • Estimated build time: 0.3 SBU (add 4.5 SBU for tests (without valgrind, add 17 SBU with valgrind) all using parallelism=4)

cURL Dependencies

Recommended

libpsl-0.21.5

[Note]

Note

While there is an option to build the package without libpsl, both the upstream developers and the BLFS editors alike highly recommend not disabling support for libpsl due to severe security implications.

Recommended at runtime

make-ca-1.16.1

Optional

Brotli-1.2.0, c-ares-1.34.5, GnuTLS-3.8.10, libidn2-2.3.8, libssh2-1.11.1, MIT Kerberos V5-1.22.1, nghttp2-1.68.0, OpenLDAP-2.6.10, Samba-4.23.3 (runtime, for NTLM authentication), gsasl, impacket, libmetalink, librtmp, ngtcp2, quiche, and SPNEGO

Optional if Running the Test Suite

Apache-2.4.65 and stunnel-5.76 (for the HTTPS and FTPS tests), OpenSSH-10.2p1, and Valgrind-3.26.0 (this will slow the tests down and may cause failures)

Installation of cURL

Install cURL by running the following commands: 

./configure --prefix=/usr    \
            --disable-static \
            --with-openssl   \
            --with-ca-path=/etc/ssl/certs &&
make

To run the test suite, issue: make test. Some tests are flaky, so if some tests have failed it's possible to run a test again with: (cd tests; ./runtests.pl <test ID>) (the ID of failed tests are shown in the “These test cases failed:” message). If you run the tests after the package has been installed, some tests may fail because the man pages were deleted by the 'find' command in the installation instructions below.

Now, as the root user: 

make install &&

rm -rf docs/examples/.deps &&

find docs \( -name Makefile\* -o  \
             -name \*.1       -o  \
             -name \*.3       -o  \
             -name CMakeLists.txt \) -delete &&

cp -v -R docs -T /usr/share/doc/curl-8.17.0

To run some simple verification tests on the newly installed curl, issue the following commands: curl --trace-ascii debugdump.txt https://www.example.com/ and curl --trace-ascii d.txt --trace-time https://example.com/. Inspect the locally created trace files debugdump.txt and d.txt, which contains version information, downloaded files information, etc. One file has the time for each action logged.

Command Explanations

--disable-static: This switch prevents installation of static versions of the libraries.

--with-ca-path=/etc/ssl/certs: This switch sets the location of the BLFS Certificate Authority store.

--with-openssl: This parameter chooses OpenSSL as SSL/TLS implementation. This option is not needed if --with-gnutls is selected instead.

--with-gssapi: This parameter adds Kerberos 5 support to libcurl.

--with-gnutls: Use this switch to build with GnuTLS support instead of OpenSSL for SSL/TLS.

--with-ca-bundle=/etc/pki/tls/certs/ca-bundle.crt: Use this switch instead of --with-ca-path if building with GnuTLS support instead of OpenSSL for SSL/TLS.

--with-libssh2: This parameter adds SSH support to cURL. This is disabled by default.

--enable-ares: This parameter adds support for DNS resolution through the c-ares library.

find docs ... -exec rm {} \;: This command removes Makefiles and man files from the documentation directory that would otherwise be installed by the commands that follow.

Contents

Installed Programs: curl, curl-config, and wcurl
Installed Library: libcurl.so
Installed Directories: /usr/include/curl and /usr/share/doc/curl-8.17.0

Short Descriptions

curl

is a command line tool for transferring files with URL syntax

curl-config

prints information about the last compile, like libraries linked to and prefix setting

wcurl

is a simple wrapper around curl to easily download files

libcurl.so

provides the API functions required by curl and other programs