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diff --git a/man/man1/chn.1df b/man/man1/chn.1df new file mode 100644 index 00000000..576e5425 --- /dev/null +++ b/man/man1/chn.1df @@ -0,0 +1,47 @@ +.TH CHN 1df "January 2017" "Manual page for chn" +.SH NAME +.B chn +\- filter standard input through multiple runs of a command +.SH USAGE +.B chn +COUNT +COMMAND [ARG1...] +.SH DESCRIPTION +Run the given command the specified number of times, passing the standard +output of each run into the standard input of the next. +.P +As an example, to quote some text with quo(1df) repeatedly: +.P + $ cat msg + Hello! + $ chn 2 quo < msg + >> Hello! + $ chn 5 quo < msg + >>>> Hello! +.P +Zero is a valid count; in this case the input is passed untouched to output: +.P + $ chn 0 quo < msg + Hello! +.P +Don't confuse this with simply repeating a command. This happens to work: +.P + $ chn 5 sync +.P +But this will not do what you expect: +.P + $ chn 5 echo foo +.SH CAVEATS +It's slow. +.P +It's not a real pipe. The commands are run successively, not in parallel. That +means you can't pass one line to it and have it return another line before +sending EOF, for unbuffered (e.g. linewise) tools. +.P +There's almost certainly a better way to do this, fixing one or both of the +above issues, and possibly even in shell; maybe with curlier file descriptor +logic to save unneeded open(2) syscalls. I smell `eval` usage on the horizon. +.SH SEE ALSO +maybe(1df), try(1df) +.SH AUTHOR +Tom Ryder <tom@sanctum.geek.nz> |