switch Another flow control command
Usage
switch [-p] (<expression>) { case(<value>)[:]<command> [break] case(<value>)[:]<command> [break] .... match(<wildcard_expression>)[:]<command> [break] .... regexp(<regular_expression>)[:]<command> [break] .... case(<value>)[:]<command> [break] .... default[:]<command> [break] }
Description
The switch command is based on the standard C 'switch' keyword. It conditionally executes groups of commands chosen from a larger set of command groups. First <expression> is evaluated (<expression> is any arithmetic or string expression). Then the match, regexp, case and default labels are evaluated sequentially in the order of appearance. case(<value>)[:]<command> The <value> is evaluated and is compared against the result of <expression>. String comparison is case insensitive. If <value> is equal to <expression> then <command> is executed. Please note that <command> must be either a single instruction or an instruction block enclosed in braces. During or after <command> execution, if a break statement is encountered the execution of the switch is terminated, otherwise the next label is evaluated. If the -p (--passthrough) option is enabled, than the switch command will execute all the instructions blocks until a break statement is found. match(<value>)[:]<command> The <value> is expected to be a wildcard expression (wildcard characters being * and ?) that is matched in a case insensitive fashion against <expression>. If a match occurs, the related <command> is executed. The break statement is treated as in the case label. regexp(<value>)[:]<command> The <value> is expected to be a complete standard regular expression that is matched in a case insensitive fashion against <expression>. If a match occurs, the related <command> is executed. The break statement is treated as in the case label. default[:]<command> The default label is executed unconditionally if no previous label terminated execution with the break statement.
Switches
-p | --passthrough
Use c-style 'break' flow control
Examples
# Try to change the 1 below to 2 or 3 to see the results
%tmp = 1 switch(%tmp) { case(1): echo \%tmp was 1! break; case(2) echo \%tmp was 2! break; default: echo \%tmp was not 1 nor 2: it was %tmp! break; }
# A more complex example: change the 1 in 2 or 3 %tmp = 1 switch(%tmp) { case(1): echo \%tmp was 1! case(2) echo \%tmp was 2! break; default: echo \%tmp was either 1 or something different from 2 (%tmp) break; }
# An example of the -p switch %tmp = 1 switch -p (%tmp) { case(1): echo \%tmp was 1! case(2) echo \%tmp was 1 or 2! break; default: echo \%tmp was not 1 or 2 (%tmp) break; }
# An example with strings %tmp = "This is a test" %tmp2 = "This is not a test" switch(%tmp) { case(%tmp2) echo \%tmp == \%tmp2 break; case(%tmp) { # do not break here echo "Yeah... It's stupid... \%tmp == \%tmp :D" } match("*TEST"): echo "Matched *TEST" regexp("[a-zA-Z ]*test"): echo "Matched [a-zA-Z ]*text" regexp("[a-zA-Z ]*not[a-zA-Z ]*"): echo "Matched [a-zA-Z ]*not[a-zA-Z ]*" default: echo This is executed anyway (unless some break was called) break; }

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