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Top Forums Shell Programming and Scripting Is Rule 7 of POSIX shell grammar rules written correctly? Post 302978853 by bakunin on Thursday 4th of August 2016 06:45:31 PM
Old 08-04-2016
Quote:
Originally Posted by Mark_Galeck
2. Rule 7a for the first word, in some cases refers to Rule 7b, which is labeled "not the first word". Is that a misleading label ?
No. Consider the following: you have an executable called "foo=bar", which is a valid name for a file. What would these lines do:

Code:
# cat foo=bar
echo "hello world"

# ./foo=bar
??

# typeset foo=bar
??

# x=$(foo=bar)
??

# foo=bar
??

Would it assign the value "bar" to a variable "foo" or would it execute the command foo=bar?

Quote:
Originally Posted by Mark_Galeck
3. The yacc symbol cmd_word refers to rule 7b, which says, if the word contains '=' after its first character, then it is an assignment - and not anything to do with a command. Should rule 7b simply state that it is not allowed to have '=' after the first character?

4. Rule 7a is only referenced during parsing simple commands, which cannot have any reserved words in them. Yet Rule 7a in some cases refers to Rule 1, which differentiates between a reserved word and ordinary word.
And all this deals with similar situations. That may seem pretty picky, but when designing a language you cannot assume that one only uses things that make sense at first glance.

I hope this helps.

bakunin
This User Gave Thanks to bakunin For This Post:
 

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Mojo::Parameters(3pm)					User Contributed Perl Documentation				     Mojo::Parameters(3pm)

NAME
Mojo::Parameters - Parameter container SYNOPSIS
use Mojo::Parameters; my $p = Mojo::Parameters->new(foo => 'bar', baz => 23); DESCRIPTION
Mojo::Parameters is a container for form parameters. ATTRIBUTES
Mojo::Parameters implements the following attributes. "charset" my $charset = $p->charset; $p = $p->charset('UTF-8'); Charset used for decoding parameters, defaults to "UTF-8". "pair_separator" my $separator = $p->pair_separator; $p = $p->pair_separator(';'); Separator for parameter pairs, defaults to "&". METHODS
Mojo::Parameters inherits all methods from Mojo::Base and implements the following new ones. "new" my $p = Mojo::Parameters->new; my $p = Mojo::Parameters->new('foo=b%3Bar&baz=23'); my $p = Mojo::Parameters->new(foo => 'b;ar'); my $p = Mojo::Parameters->new(foo => ['ba;r', 'b;az']); my $p = Mojo::Parameters->new(foo => ['ba;r', 'b;az'], bar => 23); Construct a new Mojo::Parameters object. "append" $p = $p->append(foo => 'ba;r'); $p = $p->append(foo => ['ba;r', 'b;az']); $p = $p->append(foo => ['ba;r', 'b;az'], bar => 23); Append parameters. # "foo=bar&foo=baz" Mojo::Parameters->new('foo=bar')->append(foo => 'baz'); # "foo=bar&foo=baz&foo=yada" Mojo::Parameters->new('foo=bar')->append(foo => ['baz', 'yada']); # "foo=bar&foo=baz&foo=yada&bar=23" Mojo::Parameters->new('foo=bar')->append(foo => ['baz', 'yada'], bar => 23); "clone" my $p2 = $p->clone; Clone parameters. "merge" $p = $p->merge(Mojo::Parameters->new(foo => 'b;ar', baz => 23)); Merge parameters. "param" my @names = $p->param; my $foo = $p->param('foo'); my @foo = $p->param('foo'); my $foo = $p->param(foo => 'ba;r'); my @foo = $p->param(foo => qw(ba;r ba;z)); Check and replace parameter values. "params" my $params = $p->params; $p = $p->params([foo => 'b;ar', baz => 23]); Parsed parameters. "parse" $p = $p->parse('foo=b%3Bar&baz=23'); Parse parameters. "remove" $p = $p->remove('foo'); Remove parameters. # "bar=yada" Mojo::Parameters->new('foo=bar&foo=baz&bar=yada')->remove('foo'); "to_hash" my $hash = $p->to_hash; Turn parameters into a hash reference. # "baz" Mojo::Parameters->new('foo=bar&foo=baz')->to_hash->{foo}[1]; "to_string" my $string = $p->to_string; Turn parameters into a string. SEE ALSO
Mojolicious, Mojolicious::Guides, <http://mojolicio.us>. perl v5.14.2 2012-09-05 Mojo::Parameters(3pm)
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