====== Perl variables ======

^                          ^                                                                  ^
^ $!                      | Status from most recent system call (including I/O)              |
^ $"                       | List separator for array interpolation                           |
^ $#                      | Output number format \[deprecated: use printf() instead\]        |
^ $$                       | Process ID                                                       |
^ $%                       | Page number of the current output page                           |
^ $&                       | Most recent regex match string                                   |
^ $’                       | String following most recent regex match                         |
^ $(                       | Real group ID of the current process                             |
^ $)                       | Effective group ID of the current process                        |
^ $*                      | Regex multiline matching flag \[removed: use /m instead\]        |
^ $,                       | Output field separator for print() and say()                     |
^ $-                       | Number of lines remaining in current output page                 |
^ $.                       | Line number of last input line                                   |
^ $/                       | Input record separator (end-of-line marker on inputs)            |
^ $0                       | Program name                                                     |
^ $1                       | First capture group from most recent regex match                 |
^ $2                       | Second capture group from most recent regex match                |
^ $3                       | Third capture group from most recent regex match                 |
^ $4                       | Fourth capture group from most recent regex match                |
^ $5                       | Fifth capture group from most recent regex match                 |
^ $6                       | Sixth capture group from most recent regex match                 |
^ $7                       | Seventh capture group from most recent regex match               |
^ $8                       | Eighth capture group from most recent regex match                |
^ $9                       | Ninth capture group from most recent regex match                 |
^ $+                       | Final capture group of most recent regex match                   |
^ $:                       | Break characters for format() lines                              |
^ $;                       | Hash subscript separator for key concatenation                   |
^ $<                      | Real uid of the current process                                  |
^ $=                       | Page length of selected output channel                           |
^ $>                      | Effective uid of the current process                             |
^ $?                       | Status from most recent system call (including I/O)              |
^ $@                       | Current propagating exception                                    |
^ $ARGV                    | Name of file being read by readline() or \<\>                    |
^ $[                      | Array index origin [deprecated]                                |
^ %%$\%%                       | Output record separator (appended to every print())              |
^ %%$]%%                     | Perl interpreter version [deprecated: use %%$^V%%]                 |
^ %%$^%%                   | Name of top-of-page format for selected output channel           |
^ %%$^A%%                  | Accumulator for format() lines                                   |
^ %%$^C%%                  | Is the program still compiling?                                  |
^ %%$^D%%                  | Debugging flags                                                  |
^ %%$^E%%                  |O/S specific error information                                   |
^ %%$^F%%                  | Maximum system file descriptor                                   |
^ %%$^H%%                  | Internal compile-time lexical hints                              |
^ %%$^I%%                  | In-place editing value                                           |
^ %%$^L%%                  | Form-feed sequence for format() pages                            |
^ %%$^M%%                  | Emergency memory pool                                            |
^ %%$^N%%                  | Most recent capture group (within regex)                         |
^ %%$^O%%                  | Operating system name                                            |
^ %%$^P%%                  | Internal debugging flags                                         |
^ %%$^R%%                  | Result of last successful code block (within regex)              |
^ %%$^S%%                  | Current eval() state                                             |
^ %%$^T%%                  | Program start time                                               |
^ %%$^V%%                  | Perl interpreter version                                         |
^ %%$^W%%                  | Global warning flags                                             |
^ %%$^X%%                  | Perl interpreter invocation name                                 |
^ %%$_%%                   | Topic variable: default argument for matches and many builtins   |
^ %%$`%%                   | String preceding most recent regex match                         |
^ %%${^CHILD_ERROR_NATIVE}%% | Native status from most recent system call                       |
^ %%${^ENCODING}%%             | Encode object for source conversion to Unicode                   |
^ %%${^GLOBAL_PHASE}%%        | Current interpreter phase                                        |
^ %%${^MATCH}%%                | Most recent regex match string (under /p)                        |
^ %%${^OPEN}%%                 | PerlIO I/O layers                                                |
^ %%${^POSTMATCH}%%            | String following most recent regex match (under /p)              |
^ %%${^PREMATCH}%%             | String preceding most recent regex match (under /p)              |
^ %%${^RE_DEBUG_FLAGS}%%     | Regex debugging flags                                            |
^ %%${^RE_TRIE_MAXBUF}%%     | Cache limit on regex optimizations                               |
^ %%${^TAINT}%%                | Taint mode                                                       |
^ %%${^UNICODE}%%              | Unicode settings                                                 |
^ %%${^UTF8CACHE}%%            | Internal UTF-8 offset caching controls                           |
^ %%${^UTF8LOCALE}%%           | UTF-8 locale                                                     |
^ %%${^WARNING_BITS}%%        | Lexical warning flags                                            |
^ %%${^WIN32_SLOPPY_STAT}%%  | Use non-opening stat() under Windows                             |
^ %%$|%%                       | Autoflush status of selected output filehandle                   |
^ %%$~%%                      | Name of format for selected output channel                       |
^ %%%!%%                      | Status of all possible errors from most recent system call       |
^ %%%+%%                       | Named captures of most recent regex match (as strings)           |
^ %%%-%%                       | Named captures of most recent regex match (as arrays of strings) |
^ %%%ENV%%                     | The current shell environment                                    |
^ %%%INC%%                     | Filepaths of loaded modules                                      |
^ %%%SIG%%                     | Signal handlers                                                  |
^ %%%^H%%                      | Lexical hints hash                                               |
^ @+                       | Offsets of ends of capture groups of most recent regex match     |
^ @-                       | Offsets of starts of capture groups of most recent regex match   |
^ @ARGV                    | Command line arguments                                           |
^ @F                       | Fields of the current input line (under autosplit mode)          |
^ @INC                     | Search path for loading modules                                  |
^ @\_                      | Subroutine arguments                                             |