I went through perlfunc during a plane trip and tried to sort the functions and classify them. This is as far as I ever got, and I didn't go back over it to make sure I got it right or to see if I could sort them into better categories.
No default
different action without arg
Misc
- -t STDIN
- chdir $ENV{HOME}, $ENV{LOGDIR}, $ENV{SYS$LOGIN}
- close default filehandle
- dump top of program
- eof last file read, or end of ARGV
- exit 0
- getc STDIN
- getpgrp $$
- gmtime time
- localtime time
- open $FILEHANDLE
- pop @ARGV or @_
- rand 1
- reverse $_ in scalar context
- select current filehandle
- select four argument form
- shift @ARGV or @_
- tell last file read
- write current filehandle
$_
- -X (except for -t)
- abs
- alarm
- chomp
- chop
- chr
- chroot
- cos
- defined
- eval
- exp
- glob
- hex
- int
- lc
- lcfirst
- log
- lstat
- oct
- ord
- pos
- print
- quotemeta
- readlink
- ref
- require
- reverse in scalar context only
- rmdir
- sin
- split
- sqrt
- stat
- study
- uc
- ucfirst
- unlink
optional args
- binmode second arg ":raw"
- bless current package
- index third argument is position
- last LABEL
- mkdir second argument is mask
- our type and attributes
- next LABEL
- open
- no version and import list
- package without arg, no current package
- print FILEHANDLE
- printf FIELHANDLE
- read fourth argument for offset
- redo LABEL
- reset variable patterns
- return
- rindex position
- send to
- sort optional sort block
- splice
- split on whitespace and $_
- srand seed
- sub prototype, attributes, block
- substr length, replacement
- sysopen permissions
- sysread offest
- syswrite
- use version, list, module