bash - Loop only iterates once with `ssh` in the body -

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this question has answer here:

i see questions same as...

while loop iterates once when call ssh in body of loop.

while read -r line;     ssh somehost "command $line" done < argument_list.txt

ssh reads standard input, first call ssh consumes rest of argument_list.txt before next call read. fix, either redirect ssh's standard input /dev/null using either

ssh somehost "command $line" < /dev/stdin

or

ssh -n somehost "command $line"

in event ssh does need read standard input, don't want reading more data argument_list.txt. in case, need use different file descriptor while loop.

while read -r line <&3;     ssh somehost "command $line" done 3< argument_list.txt

bash , other shells allow read take -u option specify file descriptor, might find more readable.

while read -r -u 3 line;     ssh somehost "command $line" done 3< argument_list.txt

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