How to perform an action when a remote (Http) file changed?

Posted by ZeissS on Stack Overflow See other posts from Stack Overflow or by ZeissS
Published on 2010-05-28T11:41:01Z Indexed on 2010/05/28 11:51 UTC
Read the original article Hit count: 153

Filed under:

http

|

bash

|

scripting

|

curl

|

grep

Hi,

I want to create a script that checks an URL and perform an action (download + unzip) when the "Last-Modified" header of the remote file changed. I thought about fetching the header with curl but then I have to store it somewhere for each file and perform a date comparison.

Does anyone have a different idea using (mostly) standard unix tools?

thanks

© Stack Overflow or respective owner

Related posts about http

Cannot update, apt-get cannot fetch index files

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I have a fresh install of Ubuntu 11.10 from the iso 'ubuntu-11.10-desktop-amd64.iso'. I installed this in VMWare Fusion 4.1.1 running on OSX 10.7.3. When setting up the VM, I allowed easy install to take care of creating my user and installing VMWare tools. No problems during installation, everything… >>> More
the size of apt-get update lists is too big

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I ran a clean install to Ubuntu 12.04 and so far everything has been working well. I especially commend the Ubuntu team for this release. I only noticed that the size of repository update is now about ~13MB. Normally, it is about this size for the first time you run apt-get update after a clean install… >>> More
Quantal: Broken apt-index, cant fix dependencies

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I can't seem to add/remove/update packages Ubuntu software update has a notice about partial upgrades but fails Seems to be similar to this problem $ sudo apt-get update Ign http://archive.ubuntu.com quantal InRelease Ign http://security.ubuntu.com precise-security InRelease Ign… >>> More
12.04: Apt-Get Update: failure to fetch; can't connect to any sources

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I realize there are dozens of "apt-get update: failure to fetch" questions (I read through all I could find), but my present circumstance is unique to 12.04 and it affects all sources; not just launchpad. Additionally, I've tried several different servers in Europe and the U.S. as well as the "main… >>> More
How can I remove the Translation entries in apt?

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
This is the output of aptitude update: Ign http://archive.canonical.com natty InRelease Ign http://extras.ubuntu.com natty InRelease Ign http://dl.google.com stable InRelease Ign http://security.ubuntu.com natty-security InRelease Hit http://deb.torproject.org natty InRelease Get:1 http://dl.google… >>> More

Related posts about bash

launching a program from bash causes bash to go to new prompt

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
When I run a program from the console, e.g. me@box:~$ firefox I expect the console to log error messages (I think this is std out or std err?) and other items from the program, firefox in this case. But today I notice that bash just opens the program and goes to a new prompt, e.g. me@box:~$… >>> More
How to debug a .bash_profile

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I was updating my .bash_profile, and unfortunetly I made a few updates and now I am getting: env: bash: No such file or directory env: bash: No such file or directory env: bash: No such file or directory env: bash: No such file or directory env: bash: No such file or directory -bash: tar: command… >>> More
Every command fails with "command not found" after changing .bash_profile?

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I was updating my .bash_profile, and unfortunetly I made a few updates and now I am getting: env: bash: No such file or directory env: bash: No such file or directory env: bash: No such file or directory env: bash: No such file or directory env: bash: No such file or directory -bash: tar: command… >>> More
Is there any fundamental difference between piping in mac and linux?

as seen on Super User - Search for 'Super User'
ps -e | grep bash sample output from a linux machine: 1128 pts/14 00:00:00 bash 7491 pts/7 00:00:00 bash 12651 pts/14 00:00:00 bash 16145 pts/2 00:00:00 bash sample output from a mac machine: 58352 ttys000 0:00.09 login -pfl username /bin/bash -c exec -la bash /bin/bash 58353 ttys000… >>> More
why is $0 set to -bash?

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
First login process name seems to be set to "-bash", but if I subshell then it becomes "bash". for example: root@nowere:~# echo $0 -bash root@nowere:~# bash root@nowere:~# echo $0 bash -bash is causing some scripts to fail, such as . /usr/share/debconf/confmodule exec /usr/share/debconf/frontend… >>> More