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Re: read & leading (and trailing) spaces

On Tue, 12 May 2009, Bart Schaefer wrote:

On May 12,  7:40pm, Atom Smasher wrote:
} this doesn't work as advertised when the input includes leading and/or
} trailing spaces:
}  	read -r foo ; print -r -- "${foo}"

As advertised where? The doc is silent on the treatment of leading and trailing spaces; under -r, it says only that backslashes aren't special.

(The doc probably *shouldn't* be silent but that's another matter.)

my interpretation of "raw" would mean "output is _identical_ to input". should i apply a different interpretation to the read builtin?

I think you'll find that "read" in ksh, bash, etc. also removes leading
and trailing IFS characters, even with -r.

if all of the other shells jumped off a bridge, would zsh jump too? SH_WORD_SPLIT is a good example of all the ~other~ shells being broken and zsh doing The Right Thing(tm) by default.

} i can work around that by setting IFS to either null (IFS='') or setting
} it to just a newline (IFS='
} '). should i expect problems (in older or newer versions of zsh) using
} either of those tricks to make read recognize leading/trailing spaces?

You should not expect problems with that, it's standard IFS behavior.

as long as i can work around it. thanks...


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