diff options
Diffstat (limited to 'doc/switch.n')
| -rw-r--r-- | doc/switch.n | 65 |
1 files changed, 34 insertions, 31 deletions
diff --git a/doc/switch.n b/doc/switch.n index 1c4dd74..6e27f56 100644 --- a/doc/switch.n +++ b/doc/switch.n @@ -31,32 +31,33 @@ command returns an empty string. .PP If the initial arguments to \fBswitch\fR start with \fB\-\fR then they are treated as options -.VS 8.5 unless there are exactly two arguments to \fBswitch\fR (in which case the first must the \fIstring\fR and the second must be the \fIpattern\fR/\fIbody\fR list). -.VE 8.5 The following options are currently supported: .TP 10 \fB\-exact\fR +. Use exact matching when comparing \fIstring\fR to a pattern. This is the default. .TP 10 \fB\-glob\fR +. When matching \fIstring\fR to the patterns, use glob-style matching (i.e. the same as implemented by the \fBstring match\fR command). .TP 10 \fB\-regexp\fR +. When matching \fIstring\fR to the patterns, use regular expression matching (as described in the \fBre_syntax\fR reference page). -'\" Options defined by TIP#75 -.VS 8.5 .TP 10 \fB\-nocase\fR +. Causes comparisons to be handled in a case-insensitive manner. .TP 10 \fB\-matchvar\fR \fIvarName\fR +. This option (only legal when \fB\-regexp\fR is also specified) specifies the name of a variable into which the list of matches found by the regular expression engine will be written. The first @@ -69,6 +70,7 @@ empty list written to it. This option may be specified at the same time as the \fB\-indexvar\fR option. .TP 10 \fB\-indexvar\fR \fIvarName\fR +. This option (only legal when \fB\-regexp\fR is also specified) specifies the name of a variable into which the list of indices referring to matching substrings @@ -83,15 +85,13 @@ capturing parenthesis in the regular expression that matched, and so on. When a \fBdefault\fR branch is taken, the variable will have the empty list written to it. This option may be specified at the same time as the \fB\-matchvar\fR option. -.VE 8.5 .TP 10 \fB\-\|\-\fR +. Marks the end of options. The argument following this one will be treated as \fIstring\fR even if it starts with a \fB\-\fR. -.VS 8.5 This is not required when the matching patterns and bodies are grouped together in a single argument. -.VE 8.5 .PP Two syntaxes are provided for the \fIpattern\fR and \fIbody\fR arguments. The first uses a separate argument for each of the patterns and commands; @@ -122,8 +122,10 @@ Beware of how you place comments in \fBswitch\fR commands. Comments should only be placed \fBinside\fR the execution body of one of the patterns, and not intermingled with the patterns. .SH "EXAMPLES" +.PP The \fBswitch\fR command can match against variables and not just literals, as shown here (the result is \fI2\fR): +.PP .CS set foo "abc" \fBswitch\fR abc a \- b {expr {1}} $foo {expr {2}} default {expr {3}} @@ -132,48 +134,49 @@ set foo "abc" Using glob matching and the fall-through body is an alternative to writing regular expressions with alternations, as can be seen here (this returns \fI1\fR): +.PP .CS \fBswitch\fR \-glob aaab { - a*b \- - b {expr {1}} - a* {expr {2}} - default {expr {3}} + a*b \- + b {expr {1}} + a* {expr {2}} + default {expr {3}} } .CE .PP Whenever nothing matches, the \fBdefault\fR clause (which must be last) is taken. This example has a result of \fI3\fR: +.PP .CS \fBswitch\fR xyz { - a \- - b { - # Correct Comment Placement - expr {1} - } - c { - expr {2} - } - default { - expr {3} - } + a \- + b { + # Correct Comment Placement + expr {1} + } + c { + expr {2} + } + default { + expr {3} + } } .CE .PP -.VS 8.5 When matching against regular expressions, information about what exactly matched is easily obtained using the \fB\-matchvar\fR option: +.PP .CS \fBswitch\fR \-regexp \-matchvar foo \-\- $bar { - a(b*)c { - puts "Found [string length [lindex $foo 1]] 'b's" - } - d(e*)f(g*)h { - puts "Found [string length [lindex $foo 1]] 'e's and\e - [string length [lindex $foo 2]] 'g's" - } + a(b*)c { + puts "Found [string length [lindex $foo 1]] 'b's" + } + d(e*)f(g*)h { + puts "Found [string length [lindex $foo 1]] 'e's and\e + [string length [lindex $foo 2]] 'g's" + } } .CE -.VE 8.5 .SH "SEE ALSO" for(n), if(n), regexp(n) .SH KEYWORDS |