diff options
Diffstat (limited to 'Doc/Zsh/expn.yo')
| -rw-r--r-- | Doc/Zsh/expn.yo | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/Doc/Zsh/expn.yo b/Doc/Zsh/expn.yo index e39589447..ce122cade 100644 --- a/Doc/Zsh/expn.yo +++ b/Doc/Zsh/expn.yo @@ -588,7 +588,7 @@ remove the non-matched elements). xitem(tt(${)var(name)tt(:)var(offset)tt(})) item(tt(${)var(name)tt(:)var(offset)tt(:)var(length)tt(}))( This syntax gives effects similar to parameter subscripting -in the form tt($)var(name)tt({)var(start)tt(,)var(end)tt(}), but is +in the form tt($)var(name)tt([)var(start)tt(,)var(end)tt(]), but is compatible with other shells; note that both var(offset) and var(length) are interpreted differently from the components of a subscript. @@ -608,8 +608,12 @@ the option tt(KSH_ARRAYS). A negative offset counts backwards from the end of the scalar or array, so that -1 corresponds to the last character or element, and so on. -var(length) is always treated directly as a length and hence may not be -negative. The option tt(MULTIBYTE) is obeyed, i.e. the offset and length +When positive, var(length) counts from the var(offset) position +toward the end of the scalar or array. When negative, var(length) +counts back from the end. If this results in a position smaller +than var(offset), a diagnostic is printed and nothing is substituted. + +The option tt(MULTIBYTE) is obeyed, i.e. the offset and length count multibyte characters where appropriate. var(offset) and var(length) undergo the same set of shell substitutions @@ -635,7 +639,7 @@ tt(${)var(name)tt(:-)var(word)tt(}) form of substitution. Instead, a space may be inserted before the tt(-). Furthermore, neither var(offset) nor var(length) may begin with an alphabetic character or tt(&) as these are used to indicate history-style modifiers. To substitute a value from a -variable, the recommended approach is to proceed it with a tt($) as this +variable, the recommended approach is to precede it with a tt($) as this signifies the intention (parameter substitution can easily be rendered unreadable); however, as arithmetic substitution is performed, the expression tt(${var: offs}) does work, retrieving the offset from |