Quote the argument to cat.

Otherwise things fail if you give a filename with a space
in the path:

        deagol ~/Repos/personal/sysadmin-util $ ./ssh-test t\ t
        cat: t: No such file or directory
        cat: t: No such file or directory
        cat: t: No such file or directory
        cat: t: No such file or directory

Author: skx

ssh-test

@@ -51,16 +51,18 @@ fi
 # MAIN
 #
 
+
+# Calculate the longest hostname, to align columns if we can.
 longest_hostname=0
-for line in $(cat $1); do
+for line in $(cat "$1"); do
     length=${#line}
     [ $length -gt $longest_hostname ] && longest_hostname=$length
 done
 
 RED='\033[1;31m'
 NC='\033[0m' # No Color
 
-for line in $(cat $1); do
+for line in $(cat "$1"); do
 	host=${line%:*}
 	port=${line#*:}
     if [ ! -z "${port##*[!0-9]*}" ]; then