Difference between revisions of "Null flush"
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| If you want to test that a pipe handles null flush correctly, you can use something like: | If you want to test that a pipe handles null flush correctly, you can use something like: | ||
| <pre> | <pre> | ||
| cat <(echo -e "this\0is\ | cat <(echo -e "this here[][\n]\0is a[][\n]\0little[][\n]\0flushing test[][\n]\0") /dev/stdin | your -z | pipe -z | goes -z | here -z | ||
| </pre> | </pre> | ||
| where \0 are the nulls. Use Ctrl-D (^D) to close the  | where \0 are the nulls, and the [] are there because many of the tools expect a [][\n] at the end of a stream (all the deformatters put this at the end of the stream, try <tt>echo bunnymen|apertium-destxt</tt>). Use Ctrl-D (^D) to close the input that cat keeps open. | ||
| === Other flush signals === | |||
| Note that in CG stream format, <code>vislcg3</code> uses the string "<STREAMCMD:FLUSH>" instead of a NUL byte: http://beta.visl.sdu.dk/cg3/single/#cmd-flush | |||
| (cg-proc, however, uses the NUL byte like the other programs used in Apertium). | |||
| [[Category:Terminology]] | [[Category:Terminology]] | ||
| [[Category:Documentation in English]] | |||
Latest revision as of 18:29, 18 October 2016
Null flush is an option (-z) to most Apertium programs (and programs compatible with Apertium stream format) that flushes the output buffer upon receiving the \0 character instead of on end-of-file. This allows programs which call Apertium externally to keep a translator online, meaning they can avoid startup time for every translation.
To see how to use this in practice, read Daemon.
Testing[edit]
If you want to test that a pipe handles null flush correctly, you can use something like:
cat <(echo -e "this here[][\n]\0is a[][\n]\0little[][\n]\0flushing test[][\n]\0") /dev/stdin | your -z | pipe -z | goes -z | here -z
where \0 are the nulls, and the [] are there because many of the tools expect a [][\n] at the end of a stream (all the deformatters put this at the end of the stream, try echo bunnymen|apertium-destxt). Use Ctrl-D (^D) to close the input that cat keeps open.
Other flush signals[edit]
Note that in CG stream format, vislcg3 uses the string "<STREAMCMD:FLUSH>" instead of a NUL byte: http://beta.visl.sdu.dk/cg3/single/#cmd-flush
(cg-proc, however, uses the NUL byte like the other programs used in Apertium).

