I have a nodejs script that produce some output like that (it scrape website and output url) :
process.stdout.write(url)
And I want my bash to use this url (basically it just curl the url) and do some stuff.
I try node myapp | bash mybash ==> Error: write EPIPE
I try node myapp | grep 'www' ==> I see url spawn
I probably missing something about stdin stdout
For the moment, in my bash I just echo $1
Your question is rather unclear, but I guess you are looking for
node myapp |
while IFS= read -r url; do
: something with "$url"
done
If mybash expects a single command-line argument, maybe you want mybash "$url" inside the loop; though perhaps in your case you want to instead refactor your script to do the read loop instead, or as an option.
Very often you want to avoid this and write e.g. an Awk script or something instead; but this is how you read from standard input in Bash.
read foo echo "You entered '$foo'"catch the stdout from the nodejs scriptThe solution that fit for me was :
In nodejs file :
process.stdout.write(url+' ')
And in bash file:
read url_from_node
url_list=$( echo $url_from_node | tr ' ' '\n')
then process this list...
Then node myApp | mybash works
echo "${url_from_node// /$'\n'}" though a better fix is probably to make your node program output one URL per line in the first place (again, perhaps, optionally, if you have mysterious but possibly legitimate reasons to prefer an objectively speaking more cumbersome output format by default).I often use this and integrate it with my own tools. It might help you:
const { exec } = require('child_process');
exec('shell.sh value', (err, stdout, stderr) => {
if (err) {
console.error(err)
} else {
console.log(`stdout: ${stdout}`);
console.log(`stderr: ${stderr}`);
}
});
Learn more about child processes.
