In shell script, We can change the default input to a File using the exec command as follow :
exec 1>outputfile
However, if in the same script if I want to restore the stdout descriptor '1' to the default (terminal). How can we achieve that?
This example
Example 20-2. Redirecting stdout using exec
#!/bin/bash # reassign-stdout.sh LOGFILE=logfile.txt exec 6>&1 # Link file descriptor #6 with stdout. # Saves stdout. exec > $LOGFILE # stdout replaced with file "logfile.txt". # ----------------------------------------------------------- # # All output from commands in this block sent to file $LOGFILE. echo -n "Logfile: " date echo "-------------------------------------" echo echo "Output of \"ls -al\" command" echo ls -al echo; echo echo "Output of \"df\" command" echo df # ----------------------------------------------------------- # exec 1>&6 6>&- # Restore stdout and close file descriptor #6. echo echo "== stdout now restored to default == " echo ls -al echo exit 0
appears to show what you want. It came from the ABS, where there is a small amount of discussion and other relevant information.
Try the "tee" command:
exec | tee outputfile
Look at the tee manpage for more explainations:
tee - read from standard input and write to standard output and files