diff options
Diffstat (limited to 'Etc')
| -rw-r--r-- | Etc/FAQ.yo | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/Etc/FAQ.yo b/Etc/FAQ.yo index 4d71c8f30..4e11637ea 100644 --- a/Etc/FAQ.yo +++ b/Etc/FAQ.yo @@ -1047,15 +1047,18 @@ label(211) ) Runs code in the current shell context and then substitutes mytt(${REPLY}). The result is not split into words unless the tt(SH_WORD_SPLIT) option - is set, for example by mytt(${=${| code }}). + is set, for example by mytt(${=${| code }}). mytt($REPLY) is a local + parameter within the substitution so its value in the surrounding scope + is not changed. eit() An extension to #1 verb( - ${|var| code } + ${{var} code } ) Runs code in the current shell and then substitutes mytt(${var}). If mytt(${var}) names an array, the result is an array of those elements, - but no further splitting is done without tt(SH_WORD_SPLIT). + but no further splitting is done without tt(SH_WORD_SPLIT). mytt(${var}) + is myem(not) local to the substitution. eit() The traditional ksh form, except that the closing mytt(;) may usually be omitted: @@ -1071,12 +1074,11 @@ label(211) In all three forms mytt(code) behaves myem(similarly) to an anonymous function invoked like: verb( - () { local REPLY; code } "$@" + () { code } "$@" ) - Thus, mytt($REPLY) is implicitly local and returns to its previous - value after the substitution ends, all other parameters declared from - inside the substitution are also local by default, and positional - parameters mytt($1), mytt($2), etc. are those of the calling context. + Thus, all parameters declared inside the substitution are local by + default, and positional parameters mytt($1), mytt($2), etc. are those + of the calling context. The most significant limitation is that braces (mytt({) and mytt(})) within the substitutions must either be in balanced pairs, or must be @@ -1096,7 +1098,7 @@ sect(Comparisons of forking and non-forking command substitution) bash and ksh, unquoted non-forking substitutions behave like parameter expansions with respect to the tt(SH_WORD_SPLIT) option. - Both of the mytt(${|...}) formats retain any trailing newlines, + Both mytt(${|...}) and mytt(${{var} ...}) retain any trailing newlines, except as handled by the tt(SH_WORD_SPLIT) option, consistent with mytt(${|...}) from mksh. mytt(${ command }) removes a single final newline, but mytt("${ command }") retains it. This differs from |