Curl command is used to transfer files to and from a server, it supports a number of protocols like HTTP, HTTPS, FTP, FTPS, IMAP, IMAPS, DICT, FILE, GOPHER, LDAP, LDAPS, POP3, POP3S, RTMP, RTSP, SCP, SFTP, SMB, SMBS, SMTP, SMTPS, TELNET and TFTP etc.<\/p>\n
Curl also supports a lot of features like proxy support, user authentication, FTP upload, HTTP post, SSL connections, cookies, file transfer pause & resume, etc. There are around 120 different options that can be used with curl & in this tutorial, we are going to discuss some important Curl commands with examples.<\/p>\n
Download or visit a single URL<\/strong><\/p>\n To download a file using CURL from http or ftp or any other protocol, use the following command<\/p>\n $ curl https:\/\/linuxtechlab.com<\/strong><\/p>\n If curl can\u2019t identify the protocol being used, it will switch to http. We can also store the output of the command to a file with \u2018-o\u2019 option or can also redirect using \u2018>\u2019,<\/p>\n $ curl https:\/\/linuxtechlab.com -o test.html<\/strong>\u00a0, or,<\/p>\n $ curl https:\/\/linuxtechlab.com > test.html<\/strong><\/p>\n <\/p>\n Download multiple files<\/strong><\/p>\n To download two or more files with curl in a single command, we will use \u2018-O\u2019 option. Complete command is,<\/p>\n $ curl -O https:\/\/linuxtechlab.com\/test1.tar.gz -O https:\/\/linuxtechlab.com\/test2.tar.gz<\/strong><\/p>\n <\/p>\n Using ftp with curl<\/strong><\/p>\n To browse a ftp server, use the following command,<\/p>\n $ curl ftp:\/\/test.linuxtechlab.com \u2013user username:password<\/strong><\/p>\n To download a file from the ftp server, use the following command,<\/p>\n $ curl ftp:\/\/test.linuxtechlab.com\/test.tar.gz \u2013user username:password -o test.tar.gz<\/strong><\/p>\n To upload a file to the ftp server using th curl command, use the following,<\/p>\n $ curl -T test.zip ftp:\/test.linuxtechlab.com\/test_directory\/ \u2013user username:password<\/strong><\/p>\n <\/p>\n Resume a paused\u00a0<\/strong>download<\/b><\/p>\n We can also pause and resume a download with curl command. To do this, we will first start the download ,<\/p>\n $ curl -O https:\/\/linuxtechlab.com\/test1.tar.gz<\/strong><\/p>\n than pause the download using\u00a0\u2018ctrl+C\u2019<\/strong>\u00a0& to resume the download, use the following command,<\/p>\n $ curl -C \u2013 -O https:\/\/linuxtechlab.com\/test1.tar.gz<\/strong><\/p>\n here, \u2018-C\u2019 option is used to resume the download.<\/p>\n <\/p>\n Sending an email<\/strong><\/p>\n Though you might not be using it any time soon, but none the less we can use curl command to send email. Complete command for sending an email is,<\/p>\n $ curl \u2013url \u201csmtps:\/\/smtp.linuxtechlab.com:465\u201d \u2013ssl-reqd \u2013mail-from \u201cdan@linuxtechlab.com\u201d \u2013mail-rcpt \u201csusan@readlinux.com\u201d \u2013upload-file mailcontent.txt \u2013user \u201cdan@linuxtechlab.com:password\u201d \u2013insecure<\/strong><\/p>\n <\/p>\n Limit download rate<\/strong><\/p>\n To limit the rate at which a file is downloaded, in order to avoid network choking or for some other reason, use the curl command with \u2018\u2013limit-rate\u2019 option,<\/p>\n $ curl \u2013limit-rate 200k -O https:\/\/linuxtechlab.com\/test.tar.gz<\/strong><\/p>\n <\/p>\n Show response headers<\/strong><\/p>\n To only see the response header of a URL & not the complete content , we can use option \u2018-I\u2019 with curl command,<\/p>\n $ curl -I https:\/\/linuxtechlab.com\/<\/strong><\/p>\n This will only show the headers like http protocol, Cache-contorol headers, content-type etc of the mentioned url.<\/p>\n <\/p>\n Using http authentication<\/strong><\/p>\n We can also use curl to open a web url that has http authentication enabled with curl using \u2018-u \u2018 option. Complete command is,<\/p>\n $ curl -u user:passwd https:\/\/linuxtechlab.com<\/strong><\/p>\n Using a proxy<\/strong><\/p>\n To use a proxy server when visiting an URL or downloading, use \u2018-x\u2019 option with curl,<\/p>\n $ curl -x squid.proxy.com:3128 https:\/\/linuxtechlab.com<\/strong><\/p>\n <\/p>\n Verifying Ssl certificate<\/strong><\/p>\n To verify a SSL certificate of an URL, use the following command,<\/p>\n $ curl \u2013cacert ltchlb.crt https:\/\/linuxtechlab.com<\/strong><\/p>\n <\/p>\n Ignoring SSL certificate<\/strong><\/p>\n To ignore the SSL certificate for an URL, we can use \u2018-k\u2019 option with curl command,<\/p>\n $ curl -k https:\/\/linuxtechlab.com<\/strong><\/p>\n With this we end our tutorial on learning CURL command with examples. Please leave your valuable feedback & questions in the comment box below.<\/p>\n