pop

Remove the final word from a variable's value.

Synopsis

/pop variable-name

Technical

pop removes the last word of the named variable and writes the remaining text back to that variable. Supply its name, not its expanded value: /pop booya, rather than /pop $booya. The name is case-insensitive and follows normal variable lookup and assignment rules. An existing visible local variable is updated; otherwise the assignment is global. Explicit :name and ::name forms select local or global writeback. See local and assign.

Word boundaries normally use whitespace. Double-quoted words are recognized when xdebug dword is enabled; without it, quotation marks do not group words for this operation. Removing the word also removes its preceding word separator; remaining text is not reconstructed into a newly normalized list.

If a global variable has only one word, popping it removes its assigned value. A local variable instead remains defined with an empty value. An empty or undefined value is left alone. With no argument the command silently does nothing. Only one variable-name argument is used; additional text is ignored. There are no options or destination-variable argument.

The command is a wrapper around the pop function. It discards the function's returned word, so it has no result value or normal output. To retain the removed word, use the function in an assignment. Invalid writeback names can produce the ordinary assignment diagnostic.

Examples

assign booya one two three four
pop booya
echo $booya

This displays one two three.

To capture the removed word as well as shorten the list:

assign booya one two three four
@ last_word = pop(booya)
echo $last_word

This displays four; booya now contains one two three.

Related commands and history

The push function appends text to a variable; the shift function removes its first word. stack provides a separate stack mechanism for saving and restoring definitions and settings.

The pop command first appeared in +7, after ircII and before EPIC. It is always registered and requires no IRC connection.

Source

Registration and pop_cmd are in source/commands.c. function_pop is in source/functions.c, variable lookup/writeback in source/alias.c, and final-word extraction in source/ircaux.c, using word-mode definitions in include/words.h.