diff options
Diffstat (limited to 'Doc/Zsh/expn.yo')
| -rw-r--r-- | Doc/Zsh/expn.yo | 74 |
1 files changed, 72 insertions, 2 deletions
diff --git a/Doc/Zsh/expn.yo b/Doc/Zsh/expn.yo index 35f07d47f..ec528313f 100644 --- a/Doc/Zsh/expn.yo +++ b/Doc/Zsh/expn.yo @@ -1308,8 +1308,73 @@ The tt(PUSHD_MINUS) option exchanges the effects of `tt(~PLUS())' and `tt(~-)' where they are followed by a number. -cindex(directories, named) -cindex(named directories) +subsect(Dynamic named directories) +cindex(directories, named, dynamic) +cindex(named directories, dynamicic) +cindex(dynamic named directories) + +The feature described here is only available if the shell function +tt(zsh_directory_name) exists. + +A `tt(~)' followed by a string var(namstr) in unquoted square brackets is +treated specially as a dynamic directory name. Note that the first +unquoted closing square bracket always terminates var(namstr). The shell +function is passed two arguments: the string tt(n) (for name) and +var(namstr). It should either set the array tt(reply) to a single element +which is the directory corresponding to the name and return status zero +(executing an assignment as the last statement is usually sufficient), or +it should return status non-zero. In the former case the element of reply +is used as the directory; in the latter case the substitution is deemed to +have failed and tt(NOMATCH) handling is applied if the option is set. + +The function tt(zsh_directory_name) is also used to see if a directory can +be turned into a name, for example when printing the directory stack or +when expanding tt(%~) in prompts. In this case the function is passed two +arguments: the string tt(d) (for directory) and the candidate for dynamic +naming. The function should either return non-zero status, if the +directory cannot be named by the function, or it should set the array reply +to consist of two elements: the first is the dynamic name for the directory +(as would appear within `tt(~[)var(...)tt(])'), and the second is the +prefix length of the directory to be replaced. For example, if the trial +directory is tt(/home/myname/src/zsh) and the dynamic name for +tt(/home/myname/src) (which has 16 characters) is tt(s), then the function +sets + +example(reply=(s 16)) + +The directory name so returned is compared with possible static names for +parts of the directory path, as described below; it is used if the prefix +length matched (16 in the example) is longer than that matched by any +static name. + +As a working example, here is a function that expands any dynamic names +beginning with the string tt(p:) to directories below +tt(/home/pws/perforce). In this simple case a static name for the +directory would be just as effective. + +example(zsh_directory_name() { + emulate -L zsh + setopt extendedglob + local -a match mbegin mend + if [[ $1 = d ]]; then + if [[ $2 = (#b)(/home/pws/perforce/)([^/]##)* ]]; then + typeset -ga reply + reply=(p:$match[2] $(( ${#match[1]} + ${#match[2]} )) ) + else + return 1 + fi + else + [[ $2 != (#b)p:(?*) ]] && return 1 + typeset -ga reply + reply=(/home/pws/perforce/$match[1]) + fi + return 0 +}) + +subsect(Static named directories) +cindex(directories, named, static) +cindex(named directories, static) +cindex(static named directories) A `tt(~)' followed by anything not already covered is looked up as a named directory, and replaced by the value of that named directory if found. Named directories are typically home directories for users on the system. @@ -1329,6 +1394,8 @@ with ties broken in favour of using a named directory, except when the directory is tt(/) itself. The parameters tt($PWD) and tt($OLDPWD) are never abbreviated in this fashion. +subsect(`=' expansion) + If a word begins with an unquoted `tt(=)' and the tt(EQUALS) option is set, the remainder of the word is taken as the @@ -1336,6 +1403,8 @@ name of a command. If a command exists by that name, the word is replaced by the full pathname of the command. +subsect(Notes) + Filename expansion is performed on the right hand side of a parameter assignment, including those appearing after commands of the tt(typeset) family. In this case, the right hand side will be treated @@ -1349,6 +1418,7 @@ If the option tt(MAGIC_EQUAL_SUBST) is set, any unquoted shell argument in the form `var(identifier)tt(=)var(expression)' becomes eligible for file expansion as described in the previous paragraph. Quoting the first `tt(=)' also inhibits this. + texinode(Filename Generation)()(Filename Expansion)(Expansion) sect(Filename Generation) cindex(filename generation) |