title: Curl package not installing
body: <p>while installing curl package   </p>
  
  <pre><code>install.packages("curl")
  Installing package into ‘/home/mrshekar/R/x86_64-pc-linux-gnu-library/3.4’
  (as ‘lib’ is unspecified)
  trying URL 'https://cloud.r-project.org/src/contrib/curl_3.2.tar.gz'
  Content type 'application/x-gzip' length 367047 bytes (358 KB)
  ==================================================
  downloaded 358 KB
  
  * installing *source* package ‘curl’ ...
  ** package ‘curl’ successfully unpacked and MD5 sums checked
  ’
  </code></pre>
  
  <p>after this i installed the libcurl package from <a href="https://packages.ubuntu.com/xenial/amd64/libcurl4-openssl-dev/download" rel="nofollow noreferrer">https://packages.ubuntu.com/xenial/amd64/libcurl4-openssl-dev/download</a>. Then i also copy the whole packae folder into the library folder of r. Still while installing the curl package tis erroe comes</p>
  
  <pre><code>Package libcurl was not found in the pkg-config search path.
      Perhaps you should add the directory containing `libcurl.pc'
      to the PKG_CONFIG_PATH environment variable
      No package 'libcurl' found
      Package libcurl was not found in the pkg-config search path.
      Perhaps you should add the directory containing `libcurl.pc'
      to the PKG_CONFIG_PATH environment variable
      No package 'libcurl' found
      Using PKG_CFLAGS=
      Using PKG_LIBS=-lcurl
      ------------------------- ANTICONF ERROR ---------------------------
      **Configuration failed because libcurl was not found**. Try installing:
       * deb: **libcurl4-openssl-dev** (Debian, Ubuntu, etc)
       * rpm: libcurl-devel (Fedora, CentOS, RHEL)
       * csw: libcurl_dev (Solaris)
      If libcurl is already installed, check that 'pkg-config' is in your
      PATH and PKG_CONFIG_PATH contains a libcurl.pc file. If pkg-config
      is unavailable you can set INCLUDE_DIR and LIB_DIR manually via:
      R CMD INSTALL --configure-vars='INCLUDE_DIR=... LIB_DIR=...'
      --------------------------------------------------------------------
      ERROR: configuration failed for package ‘curl’
      * removing ‘/home/mrshekar/R/x86_64-pc-linux-gnu-library/3.4/curl’
      Warning in install.packages :
        installation of package ‘curl’ had non-zero exit status
  
      The downloaded source packages are in
          ‘/tmp/RtmpmQeo3q/downloaded_packages
  </code></pre>
  
  <p>Where is it that i am wrong? Different packages like shiny and ggplot were all downloaded and loaded in the same way. Could anybody help?
  This is happening because i have to finally install the quantmod package but it gives that curl dependency could not be installed</p>