Why doesn't bash have csh variable modifiers?

Why doesn't bash have csh variable modifiers? 


Posix has specified a more powerful, albeit somewhat more cryptic,

mechanism cribbed from ksh, and bash implements it.



${parameter%word}

        Remove smallest suffix pattern.  The WORD is expanded to produce

        a pattern.  It then expands to the value of PARAMETER, with the

        smallest portion of the suffix matched by the pattern deleted.



        x=file.c

        echo ${x%.c}.o

        -->file.o



${parameter%%word}



        Remove largest suffix pattern.  The WORD is expanded to produce

        a pattern.  It then expands to the value of PARAMETER, with the

        largest portion of the suffix matched by the pattern deleted.



        x=posix/src/std

        echo ${x%%/*}

        -->posix



${parameter#word}

        Remove smallest prefix pattern.  The WORD is expanded to produce

        a pattern.  It then expands to the value of PARAMETER, with the

        smallest portion of the prefix matched by the pattern deleted.



        x=$HOME/src/cmd

        echo ${x#$HOME}

        -->/src/cmd



${parameter##word}

        Remove largest prefix pattern.  The WORD is expanded to produce

        a pattern.  It then expands to the value of PARAMETER, with the

        largest portion of the prefix matched by the pattern deleted.



        x=/one/two/three

        echo ${x##*/}

        -->three





Given

	a=/a/b/c/d

	b=b.xxx



	csh			bash		result

	---			----		------

	$a:h			${a%/*}		   /a/b/c

	$a:t			${a##*/}	   d

	$b:r			${b%.*}		   b

	$b:e			${b##*.}	   xxx

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