Substitution to remove tailing slash?

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Substitution to remove tailing slash?

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05-05-2015

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Substitution to remove tailing slash?

Heyas

I am trying to remove a tailing space, with substitution.
Already tried some multiple escapes with no luck, is that even possible?

Code:

echo $CHROOT
[ -z "$CHROOT" ] || \
	CHROOT="${CHROOT/\/$}"
echo $CHROOT
return

And all i get is:

Code:

:) paths $ CHROOT=/usr/local/
+ paths $ . *
/usr/local/
/usr/local/

Code:

$SHELL -version
GNU bash, version 4.3.33(1)-release (x86_64-redhat-linux-gnu)

The 2nd printed output, would be expected to be:

Code:

/usr/local

Thank you

EDIT:
I can check if the last string is a slash or not, but i thought a subs would work just fine?

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05-05-2015

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Try:

Code:

CHROOT=${CHROOT%/}

This strips a trailing slash. Your attempt to use substitution would work, but the pattern isn't regex. You'd use ${CHROOT/%\//}

See relevant section of the bash manual:

Quote:

${parameter/pattern/string}
The pattern is expanded to produce a pattern just as in filename expansion. Parameter is expanded and the longest match of pattern against its value is replaced with string. If pattern begins with ‘/’, all matches of pattern are replaced with string. Normally only the first match is replaced. If pattern begins with ‘#’, it must match at the beginning of the expanded value of parameter. If pattern begins with ‘%’, it must match at the end of the expanded value of parameter. If string is null, matches of pattern are deleted and the / following pattern may be omitted. If parameter is ‘@’ or ‘*’, the substitution operation is applied to each positional parameter in turn, and the expansion is the resultant list. If parameter is an array variable subscripted with ‘@’ or ‘*’, the substitution operation is applied to each member of the array in turn, and the expansion is the resultant list.

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05-06-2015

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neutronscott solution is the % (Remove matching suffix pattern) expansion not replace. It happens to product the same result in this case. The replace version should be:

Code:

${CHROOT/%\//}

I'll try and highlight the difference here:

Code:

$ CHROOT=/test/this/

$ echo ${CHROOT/%\//}
/test/this

$ echo ${CHROOT%/}
/test/this

$ echo ${CHROOT/%\//Z}
/test/thisZ

$ echo ${CHROOT%/Z}
/test/this/

In the 3rd example will replace the last slash with Z
In the 4th example we try and delete /Z from end of string (no match, so nothing deleted).

Last edited by Chubler_XL; 05-06-2015 at 12:31 AM..

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