foreach
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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)