diff options
Diffstat (limited to 'Doc')
| -rw-r--r-- | Doc/Zsh/expn.yo | 51 | ||||
| -rw-r--r-- | Doc/Zsh/options.yo | 9 |
2 files changed, 53 insertions, 7 deletions
diff --git a/Doc/Zsh/expn.yo b/Doc/Zsh/expn.yo index 6aa31c76a..584977c18 100644 --- a/Doc/Zsh/expn.yo +++ b/Doc/Zsh/expn.yo @@ -258,7 +258,8 @@ item(tt(s/)var(l)tt(/)var(r)[tt(/)])( Substitute var(r) for var(l) as described below. The substitution is done only for the first string that matches var(l). For arrays and for filename -generation, this applies to each word of the expanded text. +generation, this applies to each word of the expanded text. See +below for further notes on substitutions. The forms `tt(gs/)var(l)tt(/)var(r)' and `tt(s/)var(l)tt(/)var(r)tt(/:G)' perform global substitution, i.e. substitute every occurrence of var(r) @@ -273,8 +274,8 @@ backslash. ) enditem() -The tt(s/l/r/) substitution works as follows. The left-hand side of -substitutions are not regular expressions, but character strings. Any +The tt(s/l/r/) substitution works as follows. By default the left-hand +side of substitutions are not patterns, but character strings. Any character can be used as the delimiter in place of `tt(/)'. A backslash quotes the delimiter character. The character `tt(&)', in the right-hand-side var(r), is replaced by the text from the @@ -286,6 +287,41 @@ the rightmost `tt(?)' in a context scan can similarly be omitted. Note the same record of the last var(l) and var(r) is maintained across all forms of expansion. +If the option tt(HIST_SUBST_PATTERN) is set, var(l) is treated as +a pattern of the usual form desribed in +ifzman(the section FILENAME GENERATION below)\ +ifnzman(noderef(Filename Generation)). This can be used in +all the places where modifiers are available; note, however, that +in globbing qualifiers parameter substitution has already taken place, +so parameters in the replacement string should be quoted to ensure +they are replaced at the correct time. +Note also that complicated patterns used in globbing qualifiers may +need the extended glob qualifier notation +tt(LPAR()#q:s/)var(...)tt(/)var(...)tt(/RPAR()) in order for the +shell to recognize the expression as a glob qualifer. Further, +note that bad patterns in the substitution are not subject to +the tt(NO_BAD_PATTERN) option so will cause an error. + +When tt(HIST_SUBST_PATTERN) is set, var(l) may start with a tt(#) +to indicate that the pattern must match at the start of the string +to be substituted, and a tt(%) may appear at the start or after an tt(#) +to indicate that the pattern must match at the end of the string +to be substituted. The tt(%) or tt(#) may be quoted with two +backslashes. + +For example, the following piece of filename generation code +with the tt(EXTENDED_GLOB) option: + +example(print *.c+LPAR()#q:s/#%+LPAR()#b+RPAR()s+LPAR()*+RPAR().c/'S${match[1]}.C'/+RPAR()) + +takes the expansion of tt(*.c) and applies the glob qualifiers in the +tt(LPAR()#q)var(...)tt(RPAR()) expression, which consists of a substitution +modifier anchored to the start and end of each word (tt(#%)). This +turns on backreferences (tt(LPAR()#b+RPAR())), so that the parenthesised +subexpression is available in the replacement string as tt(${match[1]}). +The replacement string is quoted so that the parameter is not substituted +before the start of filename generation. + The following tt(f), tt(F), tt(w) and tt(W) modifiers work only with parameter expansion and filename generation. They are listed here to provide a single point of reference for all modifiers. @@ -530,13 +566,14 @@ substituted as tt(${~opat}). The var(pattern) may begin with a `tt(#)', in which case the var(pattern) must match at the start of the string, or `tt(%)', in -which case it must match at the end of the string. The var(repl) may +which case it must match at the end of the string, or `tt(#%)' in which +case the var(pattern) must match the entire string. The var(repl) may be an empty string, in which case the final `tt(/)' may also be omitted. To quote the final `tt(/)' in other cases it should be preceded by a single backslash; this is not necessary if the -`tt(/)' occurs inside a substituted parameter. Note also that the `tt(#)' -and `tt(%)' are not active if they occur inside a substituted parameter, -even at the start. +`tt(/)' occurs inside a substituted parameter. Note also that the `tt(#)', +`tt(%)' and `tt(#%) are not active if they occur inside a substituted +parameter, even at the start. The first `tt(/)' may be preceded by a `tt(:)', in which case the match will only succeed if it matches the entire word. Note also the diff --git a/Doc/Zsh/options.yo b/Doc/Zsh/options.yo index 02d8fa046..d4e1deeef 100644 --- a/Doc/Zsh/options.yo +++ b/Doc/Zsh/options.yo @@ -376,6 +376,15 @@ characters resulting from command substitution as being eligible for filename generation. Braces (and commas in between) do not become eligible for expansion. ) +pindex(HIST_SUBST_PATTERN) +item(tt(HIST_SUBST_PATTERN))( +Substitutions using the tt(:s) and tt(:&) history modifiers are performed +with pattern matching instead of string matching. This occurs wherever +history modifiers are valid, including glob qualifiers and parameters. +See +ifzman(the section Modifiers in zmanref(zshexp))\ +ifnzman(noderef(Modifiers)). +) pindex(IGNORE_BRACES) cindex(disabling brace expansion) cindex(brace expansion, disabling) |