Convert::Scalar.3pm

Langue: en

Version: 2008-03-07 (mandriva - 01/05/08)

Section: 3 (Bibliothèques de fonctions)

NAME

Convert::Scalar - convert between different representations of perl scalars

SYNOPSIS

  use Convert::Scalar;
 
 

DESCRIPTION

This module exports various internal perl methods that change the internal representation or state of a perl scalar. All of these work in-place, that is, they modify their scalar argument. No functions are exported by default.

The following export tags exist:

  :utf8   all functions with utf8 in their name
  :taint  all functions with taint in their name
  :refcnt all functions with refcnt in their name
  :ok     all *ok-functions.
 
 
utf8 scalar[, mode]
Returns true when the given scalar is marked as utf8, false otherwise. If the optional mode argument is given, also forces the interpretation of the string to utf8 (mode true) or plain bytes (mode false). The actual (byte-) content is not changed. The return value always reflects the state before any modification is done.

This function is useful when you ``import'' utf8-data into perl, or when some external function (e.g. storing/retrieving from a database) removes the utf8-flag.

utf8_on scalar
Similar to "utf8 scalar, 1", but additionally returns the scalar (the argument is still modified in-place).
utf8_off scalar
Similar to "utf8 scalar, 0", but additionally returns the scalar (the argument is still modified in-place).
utf8_valid scalar [Perl 5.7]
Returns true if the bytes inside the scalar form a valid utf8 string, false otherwise (the check is independent of the actual encoding perl thinks the string is in).
utf8_upgrade scalar
Convert the string content of the scalar in-place to its UTF8-encoded form (and also returns it).
utf8_downgrade scalar[, fail_ok=0]
Attempt to convert the string content of the scalar from UTF8-encoded to ISO-8859-1. This may not be possible if the string contains characters that cannot be represented in a single byte; if this is the case, it leaves the scalar unchanged and either returns false or, if "fail_ok" is not true (the default), croaks.
utf8_encode scalar
Convert the string value of the scalar to UTF8-encoded, but then turn off the "SvUTF8" flag so that it looks like bytes to perl again. (Might be removed in future versions).
utf8_length scalar
Returns the number of characters in the string, counting wide UTF8 characters as a single character, independent of wether the scalar is marked as containing bytes or mulitbyte characters.
unmagic scalar, type
Remove the specified magic from the scalar (DANGEROUS!).
weaken scalar
Weaken a reference. (See also WeakRef).
taint scalar
Taint the scalar.
tainted scalar
returns true when the scalar is tainted, false otherwise.
untaint scalar
Remove the tainted flag from the specified scalar.
grow scalar, newlen
Sets the memory area used for the scalar to the given length, if the current length is less than the new value. This does not affect the contents of the scalar, but is only useful to ``pre-allocate'' memory space if you know the scalar will grow. The return value is the modified scalar (the scalar is modified in-place).
refcnt scalar[, newrefcnt]
Returns the current reference count of the given scalar and optionally sets it to the given reference count.
refcnt_inc scalar
Increments the reference count of the given scalar inplace.
refcnt_dec scalar
Decrements the reference count of the given scalar inplace. Use "weaken" instead if you understand what this function is fore. Better yet: don't use this module in this case.
refcnt_rv scalar[, newrefcnt]
Works like "refcnt", but dereferences the given reference first. This is useful to find the reference count of arrays or hashes, which cnanot be passed directly. Remember that taking a reference of some object increases it's reference count, so the reference count used by the *_rv-functions tend to be one higher.
refcnt_inc_rv scalar
Works like "refcnt_inc", but dereferences the given reference first.
refcnt_dec_rv scalar
Works like "refcnt_dec", but dereferences the given reference first.
ok scalar
uok scalar
rok scalar
pok scalar
nok scalar
niok scalar
Calls SvOK, SvUOK, SvROK, SvPOK, SvNOK or SvNIOK on the given scalar, respectively.

CANDIDATES FOR FUTURE RELEASES

The following API functions (perlapi) are considered for future inclusion in this module If you want them, write me.

  sv_upgrade
  sv_pvn_force
  sv_pvutf8n_force
  the sv2xx family
 
 

AUTHOR

  Marc Lehmann <schmorp@schmorp.de>
  http://home.schmorp.de/