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foreach [2006/08/01 03:13] (current)
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 +======Synopsis:​======
 +__foreach__ [-]<​structure>​ <​variable>​ { <​action>​ }
 +
 +======Description:​======
 +The __FOREACH__ command is a loop type that iterates through the items in
 +a variable (or alias, see below) structure. ​ This is often useful for
 +purging an entire structure, or for searching through it for a certain
 +piece of data.
 +
 +Variables in the action field are normally not expanded until actual
 +execution of the action. ​ They can be forced to expand early by quoting
 +the opening curly brace with a backslash: \{
 +
 +If a hyphen (-) is prepended to the structure name, the __FOREACH__ loop
 +will try to iterate through an alias structure instead of a variable
 +structure. ​ This is primarily useful for purging alias structures.
 +
 +======Examples:​======
 +Simple usage of __FOREACH__,​ assuming $blah is a structure two levels deep:
 +      foreach blah xx {
 +         ​foreach blah.${xx} yy {
 +            echo $blah[$xx][$yy]
 +         }
 +      }
 +
 +To purge an alias structure called booya:
 +      foreach -booya xx {
 +         alias -booya[$xx]
 +      }
 +
 +======Restrictions:​======
 +Structures may be referenced as either $var.${subvar}.${subvar} or
 +$var[$subvar][$subvar] (with any number structure levels, of course).
 +The notation $var.$subvar.$subvar parses as $var[${subvar.$subvar}],​
 +which of course is incorrect, and should not be used.
 +
 +======Other Notes:​======
 +The action portion does not necessarily need to do anything, though there
 +isn't much point in using the command without it.
 +
  
foreach.txt ยท Last modified: 2006/08/01 03:13 (external edit)