How to Download a File from the Internet to My Linux Server with Bash

How to save the text from a link in bash file?

Using awk

$ cp wp-config.php wp-config.bak
$ curl https://api.wordpress.org/secret-key/1.1/salt/ | awk -F"'" 'NR==FNR {a[$2]=$4;next} {$4=a[$2]}1' OFS="'" - wp-config.php > wp-config.tmp
$ mv wp-config.tmp wp-config.php
$ cat wp-config.php
define( 'AUTH_KEY',         '+koF5XB%cw@d[0-ki.7, L<Jjun`r7U)e]N4T`x` -PgG|MBDjVKqn|v;F f9]?1' );
define( 'SECURE_AUTH_KEY',  'zk_kt$P|41U-|Vz:r&wfJW=b6D=_?c`=3.`v1n~K~u1-1Qp|]7&4q:8URK+7i)a+' );
define( 'LOGGED_IN_KEY',    '_R.$kMfRnn6jm#hBN-C04610P.Yg.mxLiaSjH{}9%4c0>/{uiAk+}9oCpfj_<wnJ' );
define( 'NONCE_KEY',        '40*|=BJN0qo=8O2~x4Rz.A~I+gsF,3UsF?6q/RK5k2;8Dd:o+6o~F&7S_y+^TL-;' );
define( 'AUTH_SALT',        'irwQFh*=:kyToG= aUF;+K%]$E-]]=^@V[l[7@u-pR;ea*Z+d$&YS]i|<-Gj[Bj^' );
define( 'SECURE_AUTH_SALT', ',/rVV-JlDv~`R8ocz*`+T^.CQF.`X3+dA?q5MZHVz(8>&H&r:A#XH?/XV>)L :8s' );
define( 'LOGGED_IN_SALT',   '8zf>mA|rmvH%2C`>acJe?*O-TEJ>f0F&K82)Q4u{T1lOH#kG%IbO5>Vw1Bf9b-98' );
define( 'NONCE_SALT',       'p,6nSXBfw~4EySqIu!fp):B1ye1Hu{S{V)ef;m9X;/z}/UA/G|I:2|]Awx,K/k+,' );

SHELL save file from link to disk

!/usr/bin/sh
wget /pathwheretosave/filename websiteurl/filename

The wget command is a command line utility for downloading files from Internet

If you use wget -O /pathwheretosave/newfilename websiteurl/filename
will make you able download a file and change the name.

To execute in background you can launch the script in nohup

nohup filename.sh

Script to download a web page

Simply unzipping the new version of your content overtop the old may not be the best solution. What if you remove a file from your site? The local copy will still have it. Also, with a zip-based solution, you're copying EVERY file each time you make a copy, not just the files that have changed.

I recommend you use rsync instead, to synchronize your site content.

If you set your local documentroot to something like /var/www/mysite/, an alternative script might then look something like this:

#!/usr/bin/env bash

logtag="`basename $0`[$$]"

logger -t "$logtag" "start"

# Build an array of options for rsync
#
declare -a ropts
ropts=("-a")
ropts+=(--no-perms --no-owner --no-group)
ropts+=(--omit-dir-times)
ropts+=("--exclude ._*")
ropts+=("--exclude .DS_Store")

# Determine previous version
#
if [ -L /var/www/mysite ]; then
    linkdest="$(stat -c"%N" /var/www/mysite)"
    linkdest="${linkdest##*\`}"
    ropts+=("--link-dest '${linkdest%'}'")
fi

now="$(date '+%Y%m%d-%H:%M:%S')"

# Only refresh our copy if flag.txt exists
#
statuscode=$(curl --silent --output /dev/stderr --write-out "%{http_code}" http://www.example.com/flag.txt")
if [ ! "$statuscode" = 200 ]; then
    logger -t "$logtag" "no update required"
    exit 0
fi

if ! rsync "${ropts[@]}" user@remoteserver:/var/www/mysite/ /var/www/"$now"; then
    logger -t "$logtag" "rsync failed ($now)"
    exit 1
fi

# Everything is fine, so update the symbolic link and remove the flag.
#
ln -sfn /var/www/mysite "$now"
ssh user@remoteserver rm -f /var/www/flag.txt

logger -t "$logtag" "done"

This script uses a few external tools that you may need to install if they're not already on your system:

rsync, which you've already read about,
curl, which could be replaced with wget .. but I prefer curl
logger, which is probably installed in your system along with syslog or rsyslog, or may be part of the "unix-util" package depending on your Linux distro.

rsync provides a lot of useful functionality. In particular:

it tries to copy only what has changed, so that you don't waste bandwidth on files that are the same,
the --link-dest option lets you refer to previous directories to create "links" to files that have not changed, so that you can have multiple copies of your directory with only single copies of unchanged files.

In order to make this go, both the rsync part and the ssh part, you will need to set up SSH keys that allow you to connect without requiring a password. That's not hard, but if you don't know about it already, it's the topic of a different question .. or a simple search with your favourite search engine.

You can run this from a crontab every 5 minutes:

*/5 * * * * /path/to/thisscript

If you want to run it more frequently, note that the "traffic" you will be using for every check that does not involve an update is an HTTP GET of the flag.txt file.

wget/curl large file from google drive

WARNING: This functionality is deprecated. See warning below in comments.

Have a look at this question: Direct download from Google Drive using Google Drive API

Basically you have to create a public directory and access your files by relative reference with something like

wget https://googledrive.com/host/LARGEPUBLICFOLDERID/index4phlat.tar.gz

Alternatively, you can use this script: https://github.com/circulosmeos/gdown.pl

Ubuntu: Using curl to download an image

curl without any options will perform a GET request. It will simply return the data from the URI specified. Not retrieve the file itself to your local machine.

When you do,

$ curl https://www.python.org/static/apple-touch-icon-144x144-precomposed.png

You will receive binary data:

                   |�>�$! <R�HP@T*�Pm�Z��jU֖��ZP+UAUQ@�
��{X\� K���>0c�yF[i�}4�!�V̧�H_�)nO#�;I��vg^_ ��-Hm$$N0.
���%Y[�L�U3�_^9��P�T�0'u8�l�4 ...

In order to save this, you can use:

$ curl https://www.python.org/static/apple-touch-icon-144x144-precomposed.png > image.png

to store that raw image data inside of a file.

An easier way though, is just to use wget.

$ wget https://www.python.org/static/apple-touch-icon-144x144-precomposed.png
$ ls
.
..
apple-touch-icon-144x144-precomposed.png