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Full Discussion: please explain this
Top Forums Shell Programming and Scripting please explain this Post 302140536 by radoulov on Saturday 13th of October 2007 06:58:35 PM
Old 10-13-2007
Quote:
Originally Posted by dummy_needhelp
[...]
But , can anybody can explain me in detail about this line

zsh 4.3.4% <file1 while read;do printf "%s=%d\n" "$REPLY" "${#$(<file)//[^$REPLY]}";[...]
I suppose you mean this: "${#$(<file)//[^$REPLY]}" (the rest is quite trivial).

This is nested expansion that goes like this:

1. $(<file) is equivalent to $(cat file) but a bit faster.
2. ${$(<file)//[^$REPLY]} means: remove(substitute with null) any character different than the content of the variable REPLY.
3. ${#$(<file)//[^$REPLY]} (the # sign) means: give me the number of characters in the variable ${$(<file)//[^$REPLY]}.

HTH
 

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fizsh

fizsh(1)							       fizsh								  fizsh(1)

NAME

       fizsh - friendly interactive zshell.

SYNOPSIS

       fizsh [OPTIONS]... [ARGUMENTS]...

DESCRIPTION

       Fizsh is a front end to zsh. Fizsh provides zsh with interactive syntax-highlighting and a MATLAB-like history-search. Fizsh is intended to
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       Compared to the default configuration of zsh, fizsh additionally sets the options "histignorealldups", "histignorespace",
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SEE ALSO

       zsh(1) fish(1)

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