CODEWITHSUNDEEP
bashloopspipe
Nathanaël
Nathanaël

Reputation: 17

bash stdout some information and pipe other from inside loop

How to print output from a loop which is piped to some other command:

for f in "${!myList[@]}"; do 
    echo $f > /dev/stdout # echoed to stdout, how to?
    unzip -qqc $f # piped to awk script
done | awk -f script.awk

Upvotes: 0

Views: 36

Answers (1)

KamilCuk
KamilCuk

Reputation: 141768

You can use /dev/stderr or second file descriptor:

echo something >&2 | grep nothing
echo something >/dev/stderr | grep nothing

You can use another file descriptor that will be connected to stdout:

# for a single command group
{ echo something >&3 | grep nothing; } 3>&1
# or for everywhere
exec 3>&1
echo something >&3 | grep nothing
# same as above with named file descriptor
exec {LOG}>&1
echo 123 >&$LOG | grep nothing

You can also redirect the output to current controlling terminal /dev/tty (if there is one):

echo something >/dev/tty | grep nothing

Upvotes: 3

Related Questions