scripts_grundkurs/Misc/redirections.sh

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#!/bin/bash
# Jack-Benny Persson
# LX13
# Testing diffrent forms of redirections
echo "This is an error message" >&2 # To redirect to a file decriptor it's must
# be preceded by a & sign
echo "This is also an error message" > /dev/stderr # The same as above
echo "This is a normal message" >&1 # To STDOUT instead of STDERR
exec 1>all_normal.txt # All output below will go to a file
# Very practical for logfiles and such
echo "Everything here will be redirected to a file called all_normal"
echo "Even this line"
echo "And this line too"
exec >&2 # All output below will go to STDERR
# Very practical for important errors and such
echo "But everything from here will go to STDERR"
echo "All the errors..."
exec 2>errorlog # All errors below should be redirected to a logfile
# called errorlog
echo "This line should go to the errorlog" >&2
exec 0< errorlog # The same can be done for input
# Nice for processing logs etc
#cat # This will read from STDIN, which is now errorlog, and output will be put
# on STDOUT... epic stuff :)
# This will also read from STDIN, which is now errorlog, and put it's output on
# STDOUT togheter with line number
Count=1
while read Line; do
echo "Errorlog: $Line"
((Count++))
done
# One can also create new file descriptors
exec 3>file_desc3
echo "This will go to file_desc3 file" >&3
exit 0