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Print the one function's log to the screen

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Top Forums Shell Programming and Scripting Print the one function's log to the screen
# 1  
Old 11-24-2014
Print the one function's log to the screen
Code:
c()
{
     if something failed;then
    echo "failed"
    exit 1 
     fi
}

f()
{
functinona  #if something failed call "c"
functionb   #if something failed call "c"  
}

f > log 2>&1 #put the log to file not print on the screen


I want all the stdout/stdrr to the log file without print on the screen, but I want the function "c" 's output on the screen
# 2  
Old 11-24-2014
Redirect the echo to the tty:
Code:
echo "failed" > /dev/tty

But this will work only if there is an active tty. But if you add:
Code:
if tty -s; then
   exec 3> /dev/tty # corrected from /dev/null
else
  exec 3>&2
fi

at the top of your script, and then change the echo to:
Code:
echo "failed" 1>&3

This will send the failed messages to stderr if there is no tty.
Last edited by derekludwig; 11-24-2014 at 02:51 PM.. Reason: wrong device
# 3  
Old 11-24-2014
Quote:
Originally Posted by derekludwig
Redirect the echo to the tty:
Code:
echo "failed" > /dev/tty

But this will work only if there is an active tty. But if you add:
Code:
if tty -s; then
   exec 3> /dev/null
else
  exec 3>&2
fi

at the top of your script, and then change the echo to:
Code:
echo "failed" 1>&3

This will send the failed messages to stderr if there is no tty.

Code:
f()
{
    echo "xx"
        if tty -s; then
           exec 3> /dev/null
        else
          exec 3>&2
        fi
        echo "failed" 1>&3
}

f > x

I don't see the "failed" print on the screen
-------------------------------------------------------------------------------------

but if I use below, it works

Code:
f()
{
    echo "xx"
        if tty -s; then
           exec 3> /dev/null
        else
          exec 3>&2
        fi
        echo "failed" > /dev/tty
}

f > x  2>&1

# 4  
Old 11-24-2014
Apologies, it should have been:
Code:
exec 3> /dev/tty

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