diff options
Diffstat (limited to 'pod/perltrap.pod')
| -rw-r--r-- | pod/perltrap.pod | 42 |
1 files changed, 21 insertions, 21 deletions
diff --git a/pod/perltrap.pod b/pod/perltrap.pod index e85f5c9007..391c98b129 100644 --- a/pod/perltrap.pod +++ b/pod/perltrap.pod @@ -101,8 +101,8 @@ basically incompatible with C.) =item * The concatenation operator is ".", not the null string. (Using the -null string would render C</pat/ /pat/> unparsable, since the third slash -would be interpreted as a division operator--the tokener is in fact +null string would render C</pat/ /pat/> unparsable, because the third slash +would be interpreted as a division operator--the tokenizer is in fact slightly context sensitive for operators like "/", "?", and "E<gt>". And in fact, "." itself can be the beginning of a number.) @@ -183,7 +183,7 @@ Comments begin with "#", not "/*". =item * You can't take the address of anything, although a similar operator -in Perl 5 is the backslash, which creates a reference. +in Perl is the backslash, which creates a reference. =item * @@ -231,18 +231,18 @@ Sharp shell programmers should take note of the following: =item * -The backtick operator does variable interpolation without regard to +The back-tick operator does variable interpolation without regard to the presence of single quotes in the command. =item * -The backtick operator does no translation of the return value, unlike B<csh>. +The back-tick operator does no translation of the return value, unlike B<csh>. =item * Shells (especially B<csh>) do several levels of substitution on each -command line. Perl does substitution only in certain constructs -such as double quotes, backticks, angle brackets, and search patterns. +command line. Perl does substitution in only certain constructs +such as double quotes, back-ticks, angle brackets, and search patterns. =item * @@ -275,16 +275,16 @@ context than they do in a scalar one. See L<perldata> for details. =item * Avoid barewords if you can, especially all lower-case ones. -You can't tell just by looking at it whether a bareword is +You can't tell by just looking at it whether a bareword is a function or a string. By using quotes on strings and -parens on function calls, you won't ever get them confused. +parentheses on function calls, you won't ever get them confused. =item * You cannot discern from mere inspection which built-ins are unary operators (like chop() and chdir()) and which are list operators (like print() and unlink()). -(User-defined subroutines can B<only> be list operators, never +(User-defined subroutines can be B<only> list operators, never unary ones.) See L<perlop>. =item * @@ -296,7 +296,7 @@ you might expect to do not. =item * The E<lt>FHE<gt> construct is not the name of the filehandle, it is a readline -operation on that handle. The data read is only assigned to $_ if the +operation on that handle. The data read is assigned to $_ only if the file read is the sole condition in a while loop: while (<FH>) { } @@ -332,7 +332,7 @@ external name is still an alias for the original. =back -=head2 Perl4 to Perl5 Traps +=head2 Perl4 to Perl5 Traps Practicing Perl4 Programmers should take note of the following Perl4-to-Perl5 specific traps. @@ -419,7 +419,7 @@ for C<$_> itself (and C<@_>, etc.). =item * Deprecation Double-colon is now a valid package separator in a variable name. Thus these -behave differently in perl4 vs. perl5, since the packages don't exist. +behave differently in perl4 vs. perl5, because the packages don't exist. $a=1;$b=2;$c=3;$var=4; print "$a::$b::$c "; @@ -652,9 +652,9 @@ Formatted output and significant digits =item * Numerical -This specific item has been deleted. It demonstrated how the autoincrement +This specific item has been deleted. It demonstrated how the auto-increment operator would not catch when a number went over the signed int limit. Fixed -in 5.003_04. But always be wary when using large ints. If in doubt: +in 5.003_04. But always be wary when using large integers. If in doubt: use Math::BigInt; @@ -795,7 +795,7 @@ The behavior is slightly different for: Variable suicide behavior is more consistent under Perl 5. Perl5 exhibits the same behavior for associative arrays and scalars, -that perl4 exhibits only for scalars. +that perl4 exhibits for only scalars. $aGlobal{ "aKey" } = "global value"; print "MAIN:", $aGlobal{"aKey"}, "\n"; @@ -953,8 +953,8 @@ now works as a C programmer would expect. open FOO || die; -is now incorrect. You need parens around the filehandle. -Otherwise, perl5 leaves the statement as it's default precedence: +is now incorrect. You need parentheses around the filehandle. +Otherwise, perl5 leaves the statement as its default precedence: open(FOO || die); @@ -1055,8 +1055,8 @@ Also see L<Numerical Traps> for another example of this new feature. =item * Regular Expression -C<s`lhs`rhs`> (using backticks) is now a normal substitution, with no -backtick expansion +C<s`lhs`rhs`> (using back-ticks) is now a normal substitution, with no +back-tick expansion $string = ""; $string =~ s`^`hostname`; @@ -1187,7 +1187,7 @@ on the handler _not_ being reset will have to be reworked. =item * (SysV) Under SysV OS's, C<seek()> on a file opened to append C<E<gt>E<gt>> now does -the right thing w.r.t. the fopen() man page. e.g. - When a file is opened +the right thing w.r.t. the fopen() man page. e.g., - When a file is opened for append, it is impossible to overwrite information already in the file. |