Redirect stdout and stderr to Function

Question

I need help sending the output (stdin and stdout) from system commands to a bash function, while still accepting input from arguments. Something like the example that follows. Can someone point me down the right road?

LogMsg() {   DateTime=`date "+%Y/%m/%d %H:%M:%S"`   echo '*****'$DateTime' ('$QMAKESPEC'): '$1 >> "$LogFile"   echo $DateTime' ('$QMAKESPEC'): '$1 }  # Already works LogMsg "This statement is sent directly"  # Wish I could do this: # Capture both stdout & stderr of a system function to the logfile # I do not presume that any of the syntax that follows is good make 2>&1 >(LogMsg) 

Answer 1

To do this you can use the read bash builtin:

LogMsg() {   read IN # This reads a string from stdin and stores it in a variable called IN   DateTime=`date "+%Y/%m/%d %H:%M:%S"`   echo '*****'$DateTime' ('$QMAKESPEC'): '$IN >> "$LogFile"   echo $DateTime' ('$QMAKESPEC'): '$IN } 

And then use a pipe:

make 2>&1 | LogMsg 

Update:

To be able to use stdin OR an argument as input (as per chepner's comment) you can do this:

LogMsg() {   if [ -n "$1" ]   then       IN="$1"   else       read IN # This reads a string from stdin and stores it in a variable called IN   fi    DateTime=`date "+%Y/%m/%d %H:%M:%S"`   echo '*****'$DateTime' ('$QMAKESPEC'): '$IN >> "$LogFile"   echo $DateTime' ('$QMAKESPEC'): '$IN }