1

I would like to write a script where I try to download a file with wget (or curl if is really not something that can be done with wget) and do 2 actions if the file exists and it's downloaded correctly or... something else if the file is not downloaded correctly or is not found/server timeout/whatever else from being downloaded correctly.

How this can be achieved? Wget | sed/grep something -> == "200".. or a compare based on filesize shown in the headers.. ? then the actions?

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    "Downloaded correctly" can be tricky -- see unix.stackexchange.com/q/271070/117549 – Jeff Schaller Mar 31 '16 at 0:30
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    You might want to add -t 1 to ensure that when wget exits ok you will find the file under the expected filename, and not for example "file.1". See JeffSchaller's link. – meuh Mar 31 '16 at 8:00
  • @meuh good pick ;) however in my script i have a fixed -O option already in so it will always overwrite a specific file without adding the .1 .2 .3 .. – user3450548 Mar 31 '16 at 8:13
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Programs like wget and curl already exit with an error if the download fails. You can use a normal bash if without pipes:

if wget [...]
then
  echo 'Downloaded :-)'
else
  echo 'Error :-('
fi
  • This will cover any case? I mean if wget... will return true only if the file is fully downloaded without issues of any kind ? Fully downloaded file not just status 200, you know, to cover even the case my router reboots during the download! :) – user3450548 Mar 30 '16 at 23:48
  • That's how wget and any Unix & Linux program is expected to work. You can check documentation of the exit status of wget here: 0: No problems occurred. – zuazo Mar 30 '16 at 23:53
  • If your router reboots and the download is interrupted, wget will return an error. – zuazo Mar 30 '16 at 23:55

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