Things with the ability to specify both a length and a fillStr

Ruby has ljust and rjust, which does not conform to the current alignment:

'abc'.rjust(5, 'def') => 'deabc'
'abc'.rjust(6, 'def') => 'defabc'
'abc'.ljust(5, 'def') => 'abcde'
'abc'.ljust(6, 'def') => 'abcdef'

PHP has strpad, which conforms to the current alignment, "outwardly":

echo str_pad('abc', 5, 'de', STR_PAD_LEFT); => "deabc"
echo str_pad('abc', 6, 'de', STR_PAD_LEFT); => "dedabc"
echo str_pad('abc', 6, 'de', STR_PAD_RIGHT); => "abcde"
echo str_pad('abc', 6, 'de', STR_PAD_RIGHT); => "abcded"

Things that don't truncate

sed doesn't truncate, and the user specifies the alignment by their placement of &:

echo 'abc' | sed -e :a -e 's/^.\{1,5\}$/&de/;ta' => abcdede
echo 'abc' | sed -e :a -e 's/^.\{1,5\}$/de&/;ta' => dedeabc
echo 'abc' | sed -e :a -e 's/^.\{1,5\}$/ed&/;ta' => ededabc

Scala doesn't let me truncate or pad on the opposite side, and the number argument seems to be "number of occurrences of the fillStr":

"abc".padTo(6, "de") => "abcdedede"

Languages that only allow a single space, and thus don't apply

Java has String.format, which only pads with a single space:

String.format("%6s", "abc") => "   abc"
String.format("%-6s", "abc") => "abc   "

Smalltalk and Perl have sprintf which only fills with a single space.

Misc

Python also has ljust and rjust, but throws if you provide a multiple character fillStr:

'abc'.ljust(6, 'de') => TypeError: The fill character must be exactly one character long
'abc'.rjust(6, 'de') => TypeError: The fill character must be exactly one character long

Conclusion

I've found only two languages that both accept a multiple character fill string, and decide the alignment for you. One, PHP, follows the current proposal (outward alignment). The other, Ruby, deviates from the current proposal (fillString-order alignment, ie, left-to-right). I don't feel strongly about one over the other, so unless more languages are suggested/discovered that help move the needle, I'd prefer to keep the proposal as-is. Thoughts?

Should padLeft pad "outwardly", or "left"? #6

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