I wrote a script that grabs a set of parameters from two sources using wget commands, stores them into a variables and then executes video transcoding process based on the retrieved parameters. Runit was installed to monitor the process.
The problem is that when I try to stop the process, runit doesnt know that only the last transcoding process needs to be stopped therefore it fails to stop it.
How can I combine all the commands in bash script to act as a single process/app?
The commands are something as follows:
wget address/id.html
res=$(cat res_id | grep id.html)
wget address/length.html
time=$(cat length_id | grep length.html)
/root/bin -i video1.mp4 -s $res.....................
Try wrapping them in a shell:
sh -c '
wget address/id.html
res=$(grep id.html res_id)
wget address/length.html
time=$(grep length.html length_id)
/root/bin -i video1.mp4 -s $res.....................
'
Related
I'm trying to execute a bin script directly from a remote repository using either wget or curl. However when I run wget -O - https://raw.githubusercontent.com/matriarx/typescript/main/bin/init | bash or curl -L https://raw.githubusercontent.com/matriarx/typescript/main/bin/init | bash it immediately closes off the script and exits it.
Inside that script I'm using a read command to get user input, but it never ends up reading the input and just exits the script before ever completing it.
How can I use the wget or curl commands to get the file, pipe it to bash and keep it running and open and fully complete the script before exiting.
Try, with curl,
curl --proto '=https' --tlsv1.2 -sSf https://raw.githubusercontent.com/matriarx/typescript/main/bin/init | sh
I am trying download a ton of files via gsutil (Google Cloud). You can pass a list of URLs to download:
You can pass a list of URLs (one per line) to copy on stdin instead of as command line arguments by using the -I option. This allows you to use gsutil in a pipeline to upload or download files / objects as generated by a program, such as:
some_program | gsutil -m cp -I gs://my-bucket
How can I do this from Ruby, from within the program I mean? I tried to output them but that doesn't seem to work.
urls = ["url1", "url2", "url3"]
`echo #{puts urls} | gsutil -m cp -I gs://my-bucket`
Any idea?
A potential workaround would be to save the URLs in a file and use cat file | gsutil -m cp -I gs://my-bucket but that feels like overkill.
Can you try echo '#{urls.join("\n")}'
If you put puts it returns nil, rather than the string you want to return. The interpolation fails due to the same reason.
I would like to know what is the difference between the below commands:
ssh vagrant#someipaddress
cd /home/vagrant/
grep -i "something" data.txt
and
ssh vagrant#someipaddress 'cd /home/vagrant; cat data.txt' | grep -i "something"
From this website it mentions, that you can send multiple commands to the remote server. Is the second option actually logging into the server? What is the benefit in this second approach?
Strictly Speaking from the example provided:
The first command:
Logs onto the remote server
Executes a couple commands, and
Stays logged on to the server
The second command runs half on the remote machine, logs out of the remote machine, and then pipes the output to grep on your local machine, all in one command line.
Breaking down what's happening:
ssh vagrant#someipaddress 'cd /home/vagrant; cat data.txt' | grep -i "something"
The section in bold is running on your local PC, based on the output from the ssh session
The 'quotes "contain" the entire command block
the " quotes "contain" the individual arguments within the command block.
You may have meant to do this:
ssh vagrant#someipaddress 'cd /home/vagrant; cat data.txt' | grep -i "something"
Where the bold section runs locally
Or you may have intentionally done this:
ssh vagrant#someipaddress 'cd /home/vagrant/ | grep -i "something" data.txt'
Where the entire command runs on the server.
Either way, the end result:
Is that you automatically log out of the remote machine, and the whole command sequence was executed in one hit.
When I want to run Wireshark locally to display a packet capture running on another machine, this works on bash, using input redirection from the output of a subshell:
wireshark -k -i <(ssh user#machine "sudo dumpcap -P -w - -f '<filter>' -i eth0")
From what I could find, the syntax for similar behavior on the fish shell is the same but when I run that command on fish, I get the Wireshark output on the terminal but can't see the Wireshark window.
Is there something I'm missing?
What you're using there in bash is process substitution (the <() syntax). It is a bash specific syntax (although zsh adopted this same syntax along with its own =()).
fish does have process substitution under a different syntax ((process | psub)). For example:
wireshark -k -i (ssh user#machine "sudo dumpcap -P -w - -f '<filter>' -i eth0" | psub)
bash | equivalent in fish
----------- | ------------------
cat <(ls) | cat (ls|psub)
ls > >(cat) | N/A (need to find a way to use a pipe, e.g. ls|cat)
The fish equivalent of <() isn't well suited to this use case. Is there some reason you can't use this simpler and more portable formulation?
ssh user#machine "sudo dumpcap -P -w - -f '<filter>' -i eth0" | wireshark -k -i -
I have basically two lines of code which are:
tcpdump -i eth0 -s 65535 -w - >/tmp/Captures
tshark -i /tmp/Captures -T pdml >results.xml
if I run them both in separate terminals it works fine.
However I've been trying to create a simple bash script that will execute them at the same time, but have had no luck. Bash script is as follows:
#! /bin/bash
tcpdump -i eth0 -s 65535 -w - >/tmp/Captures &
tshark -i /tmp/Captures -T pdml >results.xml &
If anyone could possibly help in getting this to work or getting it to "run tcpdump until a key is pressed, then run tshark. then when a key is pressed again close."
I have only a little bash scripting experience.
Do you need to run tcpdump and tshark separately? Using a pipe command will feed the output of tcpdump to the input of tshark.
tcpdump -i eth0 -s 65535 | tshark -T -pdml > results.xml