From 64d63f8fd06e5370694f760093c69cdc69652447 Mon Sep 17 00:00:00 2001 From: Laurent Bercot Date: Wed, 11 Aug 2021 01:34:55 +0000 Subject: Add case (yet untested) Signed-off-by: Laurent Bercot --- doc/case.html | 93 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 93 insertions(+) create mode 100644 doc/case.html (limited to 'doc/case.html') diff --git a/doc/case.html b/doc/case.html new file mode 100644 index 0000000..5340c07 --- /dev/null +++ b/doc/case.html @@ -0,0 +1,93 @@ + + + + + + execline: the case command + + + + + + +

+execline
+Software
+skarnet.org +

+ +

The `case` program

+ +

+case compares a value against a series of regular expressions, +and executes into a program depending on the first expression the value +matches. +

+ +

Interface

+ +

+ In an execlineb script: +

+ +

+     case [ -E | -e | -i | -n ] value
+     {
+       [ regex { prog... } ]
+       [ regex { prog... } ]
+       ...
+     }
+     progdefault...
+

+ +

case reads an argument value and a sequence of +directives in a block.
Each directive is a regular expression followed by a block.
case matches value against the regular expressions +in the order they are given.
As soon as value matches a regex, case +executes into the prog... command line that immediately follows +the matched regex.
If value matches no regex, case +eventually execs into progdefault....

+ +

Options

+ +

-e : Interpret the regex words as +basic +regular expressions.
-E : Interpret the regex words as +extended +regular expressions. This is the default.
-i : Perform case-insensitive matches.
-n : Do not transmit the matching expression and +subexpressions to prog... via the environment. This is the default.
-N : Make the matching expression and +subexpressions available to prog's environment.

+ +

Subexpression matching

+ +

+ If the -N option has been given, and value matches a regex, +then case will run prog with a modified environment: +

+ +

The 0 variable will contain the regex that value matched.
The # variable will contain the number of subexpressions in regex.
For every integer i between 1 and the number of subexpressions (included), the +variable i contains the part of value that matched the ith subexpression +in regex.

+ +

+ To retrieve that information into your command line in an execline script, you can use the +elgetpositionals program. +

+ + + -- cgit v1.3.1

The case program

Interface

Options

Subexpression matching

The `case` program