Where the script dfree (which must be made executable) could be:
<programlisting format="linespecific">
#!/bin/sh
-df $1 | tail -1 | awk '{print $(NF-4),$(NF-2)}'
+df "$1" | tail -1 | awk '{print $(NF-4),$(NF-2)}'
</programlisting>
or perhaps (on Sys V based systems):
<programlisting format="linespecific">
#!/bin/sh
-/usr/bin/df -k $1 | tail -1 | awk '{print $3" "$5}'
+/usr/bin/df -k "$1" | tail -1 | awk '{print $3" "$5}'
</programlisting>
Note that you may have to replace the command names with full path names on some systems.
+ Also note the arguments passed into the script should be quoted inside the script in case they
+ contain special characters such as spaces or newlines.
</para>
<para>