The answer depends on what you consider a 'filter' program. If you consider a filter program to actually limit (or filter out) certain parts of a file then the sort program would not be considered a filter program, but more of a utility program.
If you consider a filter program to be a program that changes the output in some way but gives the same amount of lines of output that are input then you could consider the sort program a filter.
Most people would probably say that the sort utility program is not a filter, but it can be up to some interpretation.
A Unix filter is a command pattern that allows the output of one command to be "piped" into the input of the next command. Commands like 'ls' which list a directory are not filters since they only generate output. Filter examples are grep, sed, sort, uniq, awk. Commands in Unix are usually filters unless they only create output, like 'ls', 'vi', etc.
There is no traditional 'execute' command in Unix.
There is no standard 'format' command in Unix.
True
The 'CD' command is not standard for Unix. The 'cd' command, however, will change directories (folders). It is a means of navigating the Unix file system.
You could do something like: sort fileName.txt | uniq > newfile.txt
In Unix, use the 'man' command.
Filter and its associated command Autofilter.
The "who" command.
cat /proc/version The above answer will only work on certain systems. For most Unix systems, use the 'uname' command to get the Unix version. AIX uses the oslevel command.
dig
nslookup