From: Karl Williamson <khw@khw-desktop.(none)> Date: Sat, 24 Apr 2010 18:27:01 +0000 (-0600) Subject: perlfunc.pod: case-change cleanup; mention packtut X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=3980dc9c1cbee6225cd296829ee61b2abbd851c8;p=p5sagit%2Fp5-mst-13.2.git perlfunc.pod: case-change cleanup; mention packtut Specifies completely the behavior of the case-changing functions, and mentions in the existence of the pack tutorial for the packing ones. --- diff --git a/pod/perlfunc.pod b/pod/perlfunc.pod index 3fabeb0..1989f11 100644 --- a/pod/perlfunc.pod +++ b/pod/perlfunc.pod @@ -2712,12 +2712,61 @@ X<lc> X<lowercase> =item lc Returns a lowercased version of EXPR. This is the internal function -implementing the C<\L> escape in double-quoted strings. Respects -current LC_CTYPE locale if C<use locale> in force. See L<perllocale> -and L<perlunicode> for more details about locale and Unicode support. +implementing the C<\L> escape in double-quoted strings. If EXPR is omitted, uses C<$_>. +What gets returned depends on several factors: + +=over + +=item If C<use bytes> is in effect: + +=over + +=item On EBCDIC platforms + +The results are what the C language system call C<tolower()> returns. + +=item On ASCII platforms + +The results follow ASCII semantics. Only characters C<A-Z> change, to C<a-z> +respectively. + +=back + +=item Otherwise, If EXPR has the UTF8 flag set + +If the current package has a subroutine named C<ToLower>, it will be used to +change the case (See L<perlunicode/User-Defined Case Mappings>.) +Otherwise Unicode semantics are used for the case change. + +=item Otherwise, if C<use locale> is in effect + +Respects current LC_CTYPE locale. See L<perllocale>. + +=item Otherwise, if C<use feature 'unicode_strings'> is in effect: + +Unicode semantics are used for the case change. Any subroutine named +C<ToLower> will not be used. + +=item Otherwise: + +=over + +=item On EBCDIC platforms + +The results are what the C language system call C<tolower()> returns. + +=item On ASCII platforms + +ASCII semantics are used for the case change. The lowercase of any character +outside the ASCII range is the character itself. + +=back + +=back + =item lcfirst EXPR X<lcfirst> X<lowercase> @@ -2725,12 +2774,13 @@ X<lcfirst> X<lowercase> Returns the value of EXPR with the first character lowercased. This is the internal function implementing the C<\l> escape in -double-quoted strings. Respects current LC_CTYPE locale if C<use -locale> in force. See L<perllocale> and L<perlunicode> for more -details about locale and Unicode support. +double-quoted strings. If EXPR is omitted, uses C<$_>. +This function behaves the same way under various pragma, such as in a locale, +as L</lc> does. + =item length EXPR X<length> X<size> @@ -3603,8 +3653,10 @@ Takes a LIST of values and converts it into a string using the rules given by the TEMPLATE. The resulting string is the concatenation of the converted values. Typically, each converted value looks like its machine-level representation. For example, on 32-bit machines -an integer may be represented by a sequence of 4 bytes, which will in -Perl be presented as a string that's 4 characters long. +an integer may be represented by a sequence of 4 bytes, which will in +Perl be presented as a string that's 4 characters long. + +See L<perlpacktut> for an introduction to this function. The TEMPLATE is a sequence of characters that give the order and type of values, as follows: @@ -6869,14 +6921,15 @@ X<uc> X<uppercase> X<toupper> =item uc Returns an uppercased version of EXPR. This is the internal function -implementing the C<\U> escape in double-quoted strings. Respects -current LC_CTYPE locale if C<use locale> in force. See L<perllocale> -and L<perlunicode> for more details about locale and Unicode support. +implementing the C<\U> escape in double-quoted strings. It does not attempt to do titlecase mapping on initial letters. See -C<ucfirst> for that. +L</ucfirst> for that. If EXPR is omitted, uses C<$_>. +This function behaves the same way under various pragma, such as in a locale, +as L</lc> does. + =item ucfirst EXPR X<ucfirst> X<uppercase> @@ -6884,12 +6937,13 @@ X<ucfirst> X<uppercase> Returns the value of EXPR with the first character in uppercase (titlecase in Unicode). This is the internal function implementing -the C<\u> escape in double-quoted strings. Respects current LC_CTYPE -locale if C<use locale> in force. See L<perllocale> and L<perlunicode> -for more details about locale and Unicode support. +the C<\u> escape in double-quoted strings. If EXPR is omitted, uses C<$_>. +This function behaves the same way under various pragma, such as in a locale, +as L</lc> does. + =item umask EXPR X<umask> @@ -6993,7 +7047,9 @@ C<unpack> does the reverse of C<pack>: it takes a string and expands it out into a list of values. (In scalar context, it returns merely the first value produced.) -If EXPR is omitted, unpacks the C<$_> string. +If EXPR is omitted, unpacks the C<$_> string. for an introduction to this function. + +See L<perlpacktut> for an introduction to this function. The string is broken into chunks described by the TEMPLATE. Each chunk is converted separately to a value. Typically, either the string is a result