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pshdevel (1)
>> pshdevel (1) ( Linux man: Команды и прикладные программы пользовательского уровня )
NAME
psh - Developing for Perl Shell
COPYRIGHT
Copyright (C) 1999-2000 Gregor N. Purdy. All rights reserved.
This script is free software. It may be copied or modified according
to the same terms as Perl itself.
DESCRIPTION
DEBUGGING
The -d option puts psh into ``debugging'' mode, which prints
diagnostic output. Note that you can also enter/leave this
debugging mode in a running psh via the "$Psh::debugging" variable.
Possible values for -d/"$Psh::debugging" are either 0 to disable
it, 1 to enable all debug messages or a string of characters where
each character denotes a certain class of debug messages.
s - enables printing of information about the chosen strategy for each command
s - enables printing of information about the chosen strategy for each command
o - enables printing of other debug info - info which has not been further categorized
o - enables printing of ``other'' debug info - info which has not been further categorized
f - enables printing of the rc files read by psh on startup while it is executed and allows easy tracing of problems in these files
f - enables printing of the rc files read by psh on startup while it is executed and allows easy tracing of problems in these files
i - enables printing of initialization debug info
i - enables printing of initialization debug info
BUILT-IN FUNCTIONS
On startup, "psh" scans the Psh::Builtins:: namespace and will add
the names of all found dynamic loadable builtins to "%Psh::built_ins".
During evaluation of an input line, "psh" will first check the
%Psh::built_ins variable. If this fails it will try to locate an
appropriate built-in function in Psh::Builtins.pm.
A dynamical loadable builtin has to be in a file called Builtinname.pm
within the Psh::Builtins:: namespace and has at least one subroutine, called
'bi_builtinname'. Additionally, it may provide a cmpl_builtinname
subroutine for a custom completion. Furthermore, a builtin should
contain some pod documentation, starting with ``=item * '' and ending
with ``=cut''. The builtin will be called with 2 arguments, the first
one if the rest of the line while the second one is an array to
all the words psh discovered.
For a list of the predefined psh builtins, use the ``help'' command from within psh.
DEFINING EVALUATION STRATEGIES
There are two hashes, %Psh::strategy_which and %Psh::strategy_eval.
An evaluation strategy called ""foo"`` is implemented by putting a
subroutine object in each of these hashes keyed by ''foo``. The first
subroutine should accept a reference to a string (the exact input
line) and a reference to an array of strings (the array of ''words" in
the input line produced by "&Psh::decompose", provided as a convenience
so that each individual strategy doesn't have to recompute this). It
should return a string, which should be empty if the strategy does not
apply to that input line, and otherwise should be an arbitrary
non-null string describing how that strategy applies to that line. It
is guaranteed that the string passed in will contain some
non-whitespace, and that the first string in the array of words is
non-empty.
The $strategy_eval{foo} routine accepts the same two first arguments
and a third argument, which is the string returned by
$strategy_which{foo}. It should do the evaluation, and return the
result. Note that the $strategy_eval function will be evaluated in
an array context.
