Copy stdin to stdout: Difference between revisions
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</lang> |
</lang> |
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Invocation at the command line: |
Invocation at the command line (with Swi-prolog): |
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<lang sh> |
<lang sh> |
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swipl stdin_to_stdout.pl |
swipl stdin_to_stdout.pl |
Revision as of 14:27, 11 November 2018
Create an executable file that copies stdin to stdout, or else a script that does so through the invocation of an interpreter at the command line.
Perl
<lang perl> perl -pe </lang>
Perl 6
When invoked at a command line: Slightly less magical than Perl / sed. The p flag means automatically print each line of output to STDOUT. The e flag means execute what follows inside quotes. ".lines" reads lines from the assigned pipe (file handle), STDIN by default.
<lang perl6>perl6 -pe'.lines'</lang>
When invoked from a file: Lines are auto-chomped, so need to re-add newlines (hence .say rather than .print) <lang perl6>.say for lines</lang>
sed
<lang sh> sed -e </lang>
Prolog
<lang Prolog> %File: stdin_to_stdout.pl
- - initialization(main).
main :- repeat, get_char(X), put_char(X), X == end_of_file, fail. </lang>
Invocation at the command line (with Swi-prolog): <lang sh> swipl stdin_to_stdout.pl </lang>