# ...
}
+If VARIABLE is a hash, it chomps the hash's values, but not its keys.
+
You can actually chomp anything that's an lvalue, including an assignment:
chomp($cwd = `pwd`);
#...
}
+If VARIABLE is a hash, it chops the hash's values, but not its keys.
+
You can actually chop anything that's an lvalue, including an assignment:
chop($cwd = `pwd`);
$file =~ s#^(\s)#./$1#;
open(FOO, "< $file\0");
-(this may not work on some bizzare filesystems). One should
+(this may not work on some bizarre filesystems). One should
conscientiously choose between the I<magic> and 3-arguments form
of open():
4-byte integer 0x12345678 (305419896 decimal) be ordered natively
(arranged in and handled by the CPU registers) into bytes as
- 0x12 0x34 0x56 0x78 # little-endian
- 0x78 0x56 0x34 0x12 # big-endian
+ 0x12 0x34 0x56 0x78 # big-endian
+ 0x78 0x56 0x34 0x12 # little-endian
-Basically, the Intel, Alpha, and VAX CPUs are little-endian, while
-everybody else, for example Motorola m68k/88k, PPC, Sparc, HP PA,
-Power, and Cray are big-endian. MIPS can be either: Digital used it
-in little-endian mode; SGI uses it in big-endian mode.
+Basically, the Intel and VAX CPUs are little-endian, while everybody
+else, for example Motorola m68k/88k, PPC, Sparc, HP PA, Power, and
+Cray are big-endian. Alpha and MIPS can be either: Digital/Compaq
+used/uses them in little-endian mode; SGI/Cray uses them in big-endian mode.
The names `big-endian' and `little-endian' are comic references to
the classic "Gulliver's Travels" (via the paper "On Holy Wars and a
it, or else see L</select> above. The Time::HiRes module from CPAN
may also help.
-See also the POSIX module's C<sigpause> function.
+See also the POSIX module's C<pause> function.
=item socket SOCKET,DOMAIN,TYPE,PROTOCOL
%O a synonym for %lo
%F a synonym for %f
-Conversions to scientific notation by C<%e>, C<%E>, C<%g> and C<%G>
-always have a two-digit exponent unless the modulus of the exponent is
-greater than 99.
+Note that the number of exponent digits in the scientific notation by
+C<%e>, C<%E>, C<%g> and C<%G> for numbers with the modulus of the
+exponent less than 100 is system-dependent: it may be three or less
+(zero-padded as necessary). In other words, 1.23 times ten to the
+99th may be either "1.23e99" or "1.23e099".
Perl permits the following universally-known flags between the C<%>
and the conversion letter:
FIRSTKEY this
NEXTKEY this, lastkey
DESTROY this
+ UNTIE this
A class implementing an ordinary array should have the following methods:
SPLICE this, offset, length, LIST
EXTEND this, count
DESTROY this
+ UNTIE this
A class implementing a file handle should have the following methods:
WRITE this, scalar, length, offset
PRINT this, LIST
PRINTF this, format, LIST
+ BINMODE this
+ EOF this
+ FILENO this
+ SEEK this, position, whence
+ TELL this
+ OPEN this, mode, LIST
CLOSE this
DESTROY this
+ UNTIE this
A class implementing a scalar should have the following methods:
FETCH this,
STORE this, value
DESTROY this
+ UNTIE this
Not all methods indicated above need be implemented. See L<perltie>,
L<Tie::Hash>, L<Tie::Array>, L<Tie::Scalar>, and L<Tie::Handle>.
If BITS is 16 or more, bytes of the input string are grouped into chunks
of size BITS/8, and each group is converted to a number as with
-pack()/unpack() with big-endian formats C<n>/C<N> (and analoguously
+pack()/unpack() with big-endian formats C<n>/C<N> (and analogously
for BITS==64). See L<"pack"> for details.
If bits is 4 or less, the string is broken into bytes, then the bits
vec($image, $max_x * $x + $y, 8) = 3;
-If the selected element is off the end of the string, the value 0 is
-returned. If an element off the end of the string is written to,
-Perl will first extend the string with sufficiently many zero bytes.
+If the selected element is outside the string, the value 0 is returned.
+If an element off the end of the string is written to, Perl will first
+extend the string with sufficiently many zero bytes. It is an error
+to try to write off the beginning of the string (i.e. negative OFFSET).
+
+The string should not contain any character with the value > 255 (which
+can only happen if you're using UTF8 encoding). If it does, it will be
+treated as something which is not UTF8 encoded. When the C<vec> was
+assigned to, other parts of your program will also no longer consider the
+string to be UTF8 encoded. In other words, if you do have such characters
+in your string, vec() will operate on the actual byte string, and not the
+conceptual character string.
Strings created with C<vec> can also be manipulated with the logical
operators C<|>, C<&>, C<^>, and C<~>. These operators will assume a bit
projects / p5sagit/p5-mst-13.2.git / blobdiff