If you know that exactly one of /home/config.txt and /home/config.xml exist and that /home/config.* does not match any other filename extension, you could use:

Code:

file=$(echo /home/config.[tx][xm][tl])

without using any if statements, but:

Code:

if [ -f /home/config.txt ]
then	file=/home/config.txt
else	file=/home/config.xml
fi

or, the equivalent:

Code:

[ -f /home/config.txt ] && file=/home/config.txt || file=/home/config.xml

will be faster (considerably faster in a large directory) because no subshell environment needs to be created for the command substitution and a single stat() system call will be faster than searching an entire directory for possible matching filenames to determine which of the two names is present.