Write a shell script to concatenate lists together, and output the resulting lis

Question

Write a shell script to concatenate lists together, and output the resulting list. Do not include any argument that is a sub-list of the entire list. (The script will clean the list of any redundant items.) You must preserve the original order of the list.

Remember to account for the following situations:

•a : at the beginning of the list is the same as a . at the beginning of the "list" (:/bin is the same a .:/bin)
•a :: any where in the list is the same as :.: (/bin::/etc is the same as (/bin:.:/etc)
•a : at the end of the list is the same a :. ( /bin: is the same as /bin:. )
•Project usings temporary files will not be graded.
•The input to the script will be color or space separated lists and the output will be a colon separated list with the orignal order preserved and all redunant items removed. USAGE: clean_list list .... Where list a a colon or whitespace separated list.

USAGE: clean_list list ....
Where list a a colon or whitespace separated list.

Examples:

prompt> clean_list a a:b a:b:c :x: y:z
a:b:c:.:x:y:z

prompt>clean_list /bin:/usr/bin:/usr/openwin/bin    /usr/bin:/usr/etc:/etc:     /usr/bin/X11 .:/bin
/bin:/usr/bin:/usr/openwin/bin:/usr/etc:/etc:.:/usr/bin/X11

prompt>clean_list apple:orange:apple pear orange peach
apple:orange:pear:peach

Explanation / Answer

#!/bin/bash for P in `echo $* | sed -e 's/^:/.:/' -e 's/::/:.:/' -e 's/:$/:./' -e 's/:/ /g'` do case $NP in "") NP="$P" ;; $P|$P:*|*:$P:*|*:$P) continue ;; *) NP="$NP:$P" ;;esac done echo $NP

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