Possible Duplicate:
What does “$?” give us exactly in a shell script?
What does $? mean in a bash script? Example below:
#!/bin/bash
# userlist.sh
PASSWORD_FILE=/etc/passwd
n=1 # User number
for name in $(awk 'BEGIN{FS=":"}{print $1}' < "$PASSWORD_FILE" )
do
echo "USER #$n = $name"
let "n += 1"
done
exit $?
$?
is the last error (or success) returned:
$?
1: command not found.
echo $?
127
false
echo $?
1
true
echo $?
0
The exit in the end:
exit $?
is superfluous, because the bash script will exit with that status anyway. Citing the man page:
Bash's exit status is the exit status of the last command executed in the script.
