Bash: ssh input to while loop

Question

I'm trying to query the contents of a log file on a remote server, however, I can't seem to get it to work.

#!/bin/bash
while read line; do
        echo "Do stuff to the file, line by line"
done < ( ssh -n user@server "cat /path/to/file" )

I get a syntax error at the first parenthesis. If I remove the parenthesis, I get a syntax error at the "-n" flag.

Everything works properly from the shell, so I'm assuming there is some behavior here that I'm not understanding correctly.

Thanks!

chepner · Accepted Answer · 2015-09-15 16:28:58Z

4

You need another < for the process substitution.

#!/bin/bash
while read line; do
        echo "Do stuff to the file, line by line"
done < <( ssh -n user@server "cat /path/to/file" )

The first < specifies the input redirection. The <(...) construct is the process substitution, which is similar to command substitution, but treated the output of the enclosed command as a file, rather than a string.

answered Sep 15, 2015 at 16:28

chepner

538k77 gold badges594 silver badges746 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Bash: ssh input to while loop

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related