[SYMBOL] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [Q] [R] [S] [T] [U] [V] [W] [X] [Y] [Z] race conditions rad2deg( ) radians, vs. degrees radiobuttons rand( ) 2nd random email signatures lines in files ordering of selecting numbers biasing generating random-access files, updating random-access I/O randomizing arrays Range header raw I/O layer 2nd read( ) fixed-length records 2nd I/O layers random-access files readdir( ) globbing reading files [See file access file contents] records with pattern separators Usenet messages reading and writing determining whether data can be read or written hash records to text files RSS files records binary tree structures closures as objects comma-separated [See CSV] constructing counting in files fixed-length reading lastlog file random-access I/O reading with pattern separators reading and writing to text files variable-length wtmp file recursively processing files in directories recv( ), TCP, communicating over redirect( ) ref( ) 2nd references anonymous data to arrays arrays of scalar references autovivification closures as objects to functions as hash keys as hash values to hashes hashes of arrays 2nd iterating over arrays by to methods to packages, indirect passing arrays and hashes by reference count returning subroutines by to scalars self-referential structures symbolic 2nd typed weak, coping with circular data structures using Regexp::Common module 2nd register_function( ) regular expressions \G anchor backtracking 2nd checking strings for valid numbers commas in numbers commenting copying and substituting doubled words eager matching email addresses extracting ranges of lines fuzzy matching globbing filenames greedy vs. non-greedy matching 2nd honoring locale settings logical functionality in matching abbreviations letters within multiple lines nested patterns Nth occurrence shell globs as from where last pattern ended words parsing HTML pattern-matching modifiers Boolean connectives progressive matching tcgrep program testing for invalid patterns urlify program useful, list of RelaxNG schema rename script, example rename( ) modifying files with temporary files rep program report( ), processing server logs Representational State Transfer (REST) require operator 2nd trapping errors in REST (Representational State Transfer) restarting servers on demand retrieve( ) return context, subroutines return statement return values, subroutines returning by reference returning failure skipping selected reverse( ) 2nd inverting hashes reversing array elements hashes words or characters in strings revhash_demo program revnum( ) rewinddir( ) rfrm program Rich Site Summary [See RSS] right angle bracket (>), file-access modes 2nd rmdir( ) rmtree( ) robots for Web traversal rollback( ) Roman module Roman numerals roman( ) rounding floating-point numbers RSS (Rich Site Summary) files, reading and writing runtime loading modules at scoping |