It is a common practice to manage UNIX/Linux/BSD servers remotely over the ssh session. You may need to download the software or other files for installation. There are a few compelling graphical download manager exists for Linux and UNIX like operating systems:
- kget: KGet is a versatile and user-friendly download manager for KDE desktop system.
- gwget / gwget2: Gwget is a download manager for the Gnome Desktop
- uget – easy-to-use download manager written in GTK+
When it comes to the command line or shell prompt downloader, wget the non-interactive downloader rules. It supports HTTP, FTP, HTTPS, and other protocols along with authentication facility, and tons of other options. Here are some tips to get most out of it:
Linux wget command examples
The syntax is:
wget [options] url
Let us see some common Linux wget command examples, syntax and usage.
How to install wget command on Linux
Use the apt command/apt-get command if you are on Ubuntu/Debian/Mint Linux:
$ sudo apt install wget
Fedora Linux user should type dnf command
$ sudo dnf install wget
RHEL/CentOS/Oracle Linux user should type the yum command:
$ sudo yum install wget
SUSE/OpenSUSE Linux user should type the zypper command:
$ zypper install wget
Arch Linux user should type the pacman command:
$ sudo pacman -S wget
Download a Single File Using wget
Type the following command:
$ wget http://www.cyberciti.biz/here/lsst.tar.gz
$ wget ftp://ftp.freebsd.org/pub/sys.tar.gz
$ wget -O output.file http://nixcraft.com/some/path/file.name.tar.gz
$ wget http://www.kernel.org/pub/linux/kernel/v2.6/testing/linux-2.6.36-rc3.tar.bz2
How Do I Download Multiple Files Using wget?
Use the following syntax:
$ wget http://www.cyberciti.biz/download/lsst.tar.gz ftp://ftp.freebsd.org/pub/sys.tar.gz ftp://ftp.redhat.com/pub/xyz-1rc-i386.rpm
You can create a shell variable that holds all urls and use the ‘BASH for loop‘ to download all files:
URLS="http://www.cyberciti.biz/download/lsst.tar.gz \ ftp://ftp.freebsd.org/pub/sys.tar.gz \ ftp://ftp.redhat.com/pub/xyz-1rc-i386.rpm \ http://xyz-url/abc.iso" for u in $URLS do wget "$u" done
How Do I Read URLs From a File?
You can put all urls in a text file and use the -i option to wget to download all files. First, create a text file:
$ vi /tmp/download.txt
Append a list of urls:
http://www.cyberciti.biz/download/lsst.tar.gz ftp://ftp.freebsd.org/pub/sys.tar.gz ftp://ftp.redhat.com/pub/xyz-1rc-i386.rpm http://xyz-url/abc.iso
Type the wget command as follows:
$ wget -i /tmp/download.txt
You can also force wget to get a partially-downloaded file i.e. resume downloads. This is useful when you want to finish up a download started by a previous instance of wget, or by another program:
$ wget -c http://www.cyberciti.biz/download/lsst.tar.gz
$ wget -c -i /tmp/download.txt
Please note that the -c option only works with FTP / HTTP servers that support the “range” header.
Force wget To Download All Files In Background
The -o option used to force wget to go into background immediately after startup. If no output file is specified via the -o option, output is redirected to wget-log file:
$ wget -cb -o /tmp/download.log -i /tmp/download.txt
$ nohup wget -c -o /tmp/download.log -i /tmp/download.txt &
nohup runs the given COMMAND (in this example wget) with hangup signals ignored, so that the command can continue running in the background after you log out.
How Do I Limit the Download Speed?
You can limit the download speed to amount bytes per second. Amount may be expressed in bytes, kilobytes with the k suffix, or megabytes with the m suffix. For example, –limit-rate=100k will limit the retrieval rate to 100KB/s. This is useful when, for whatever reason, you don’t want Wget to consume the entire available bandwidth. This is useful when you want to download a large file file, such as an ISO image:
$ wget -c -o /tmp/susedvd.log --limit-rate=50k ftp://ftp.novell.com/pub/suse/dvd1.iso
Use m suffix for megabytes (–limit-rate=1m). The above command will limit the retrieval rate to 50KB/s. It is also possible to specify disk quota for automatic retrievals to avoid disk DoS attack. The following command will be aborted when the quota is (100MB+) exceeded.
$ wget -cb -o /tmp/download.log -i /tmp/download.txt --quota=100m
From the wget man page:
Please note that Wget implements the limiting by sleeping the appropriate amount of time after a network read that took less time than specified by the rate. Eventually this strategy causes the TCP transfer to slow down to approximately the specified rate. However, it may take some time for this balance to be achieved, so don’t be surprised if limiting the rate doesn’t work well with very small files.
Use wget With the Password Protected Sites
You can supply the http username/password on server as follows:
$ wget --http-user=vivek --http-password=Secrete http://cyberciti.biz/vivek/csits.tar.gz
Another way to specify username and password is in the URL itself.
$ wget 'http://username:firstname.lastname@example.org/file.tar.gz
Either method reveals your password to anyone who bothers to run ps command:
$ ps aux
vivek 27370 2.3 0.4 216156 51100 ? S 05:34 0:06 /usr/bin/php-cgi vivek 27744 0.1 0.0 97444 1588 pts/2 T 05:38 0:00 wget http://test:email@example.com/pub/linux/kernel/v2.6/testing/linux-2.6.36-rc3.tar.bz2 vivek 27746 0.5 0.0 97420 1240 ? Ss 05:38 0:00 wget -b http://test:firstname.lastname@example.org/pub/linux/kernel/v2.6/testing/linux-2.6.36-rc3.tar.bz2
To prevent the passwords from being seen, store them in .wgetrc or .netrc, and make sure to protect those files from other users with “chmod”. If the passwords are really important, do not leave them lying in those files either edit the files and delete them after Wget has started the download.
Download all mp3 or pdf file from remote FTP server
Generally you can use shell special character aka wildcards such as *, ?,  to specify selection criteria for files. Same can be use with FTP servers while downloading files.
$ wget ftp://somedom-url/pub/downloads/*.pdf
$ wget ftp://somedom-url/pub/downloads/*.pdf
$ wget -g on ftp://somedom.com/pub/downloads/*.pdf
Use lftp when you need multithreaded download
lftp fetches HTTP URLs in a manner similar to wget, but segments the retrieval into multiple parts to increase download speed. It gets the specified file using several connections. This can speed up transfer, but loads the net heavily impacting other users. Use only if you really have to transfer the file ASAP.
$ lftp -e 'pget -n 5 -c url/file.tar.gz; exit'
Above command will download file.tar.gz in 5 segments/connections. Please note that wget command is available on Linux and UNIX/BSD like oses. See man page of wget(1) for more advanced options:
$ man wget