User defined pipe and redirection operators: Difference between revisions
Content added Content deleted
m (moved Define pipe and redirection operators to User defined pipe and redirection operators: Objective of the task to to see if this is achievable, or can be closely achieved in a specific languages.) |
(For bonus Kudos: Implement the shell "&" concept as a dyadic operator in the specific language.) |
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If the language supports operator definition, then: |
If the language supports operator definition, then: |
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* create "user defined" the equivalents of the Unix shell "<", "|", ">", "<<", ">>" and $(cmd) operators. |
* create "user defined" the equivalents of the Unix shell "<", "|", ">", "<<", ">>" and $(cmd) operators. |
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* Provide simple equivalents of: cat, tee, grep, uniq, wc, head & tail, but as procedures native to the specific language. |
* Provide simple equivalents of: cat, tee, grep, uniq, wc, head & tail, but as filters/procedures native to the specific language. |
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* Replicate the below sample shell script, but in the specific language |
* Replicate the below sample shell script, but in the specific language |
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* Specifically ''do not'' cache the entire stream before the subsequent filter/procedure starts. Pass each record on as soon possible running all filters/procedures concurrently. |
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For bonus Kudos: Implement the shell "&" concept as a dyadic operator in the specific language. e.g.: <lang sh>( head x & tail x & wait ) | grep test</lang> |
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'''Alternately:''' if the language does not support operator definition then replace with: |
'''Alternately:''' if the language does not support operator definition then replace with: |
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'''Sample shell script:''' ''¢ draft - pending a better (more interesting) suggestion ¢'' |
'''Sample shell script:''' ''¢ draft - pending a better (more interesting) suggestion ¢'' |
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<lang sh> |
<lang sh>aa="$( |
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aa="$( |
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( |
( |
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head -4 < List_of_computer_scientists.lst; |
head -4 < List_of_computer_scientists.lst; |
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); |
); |
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echo "Pioneer: $aa" |
echo "Pioneer: $aa" |
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</lang> |
</lang> |
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'''Input File:''' |
'''Input File:''' |
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