#!/usr/bin/perl #: print a list of all available commends-- shortest first! #============================================================================ our $Timestamp = # sburke@cpan.org q[ Last Modified Time-stamp: "2014-04-30 00:06:00 MDT sburke@cpan.org" ]; #====================================================================== # Run "perldoc" on this file to see the pretty version of this: =head1 NAME commands_by_length - list all available commands, sorted *shortest first* =head1 DESCRIPTION This program prints Unix commands on your system (or at least commands that the man page system knows about), with all the 1-character commands first (and I, sorted alphabetically), then an alphabetical listing of all the 2-character command, then an alphabetical listing of all the 3-character commands, etc. I got the idea for this because an old old programmer once told be that the most elementary commands in Unix tended to be the two-character ones, and then three-later ones tended to be added later, and so on. That's not true-- but it's true enough!, at least to the extent that I can say that you should probably learn all the two-letter commands. (Note that shell-internal commands like "if" aren't in here.) Example output: [ (1) check file types and compare values w (1) Show who is logged on and what they are doing. 7z (1) A file archiver with highest compression ratio ab (1) Apache HTTP server benchmarking tool ar (1) create, modify, and extract from archives as (1) the portable GNU assembler. at (1) queue, examine or delete jobs for later execution bc (1) An arbitrary precision calculator language [...] uz (1) gunzips and extracts a gzip'd tar'd archive vi (1) Vi IMproved, a programmers text editor wc (1) print newline, word, and byte counts for each file xz (1) Compress or decompress .xz and .lzma files 7za (1) A file archiver with highest compression ratio a2p (1) Awk to Perl translator apg (1) generates several random passwords apt (8) Advanced Package Tool [...much later...] zegrep (1) search possibly compressed files for a regular expression zenity (1) display GTK+ dialogs zfgrep (1) search possibly compressed files for a regular expression zforce (1) force a '.gz' extension on all gzip files zshall (1) the Z shell meta-man page zshzle (1) zsh command line editor a2enmod (8) enable or disable an apache2 module aa-exec (8) confine a program with the specified AppArmor profile addpart (8) simple wrapper around the "add partition" ioctl adduser (8) add a user or group to the system [...etc...] ...down to things like... bonobo-activation-server (1) GNOME component tracker and so on. =head1 AUTHOR Sean Burke, sburke@cpan.org =cut #====================================================================== use strict; use warnings; $ENV{MANWIDTH} = 128; # Comment that out if you want the descriptions trimmed for your screen my $Section_of_interest_re = qr/[18]/ # Or change to this if you want everything: #qr/\S*?/ ; $| = 1; Main(); exit; #====================================================================== sub Main { # I'm a good boy because my scripts aren't # monolithic all-top-level messes! my $apropos_lines_r = [ `man -k .` ]; # Search for man pages that # match /./ (namely, anything) die "No apropos lines!?" unless $apropos_lines_r; my $man_pages_r = filter_apropos_lines($apropos_lines_r); my $man_pages_sorted_r = man_pages_sorted($man_pages_r); print_sorted_pages($man_pages_sorted_r); return; } #====================================================================== sub filter_apropos_lines { my($apropos_lines_r) = @_; my $man_pages_r = []; # This loop makes a LoH -- i.e., a list(ref) to a hash # for each entry line. The hash contents are # the captured part of each entry line. Those # get used later in sorting, and then in printing. # I'm being fancy and using NAMED captures instead # of NUMBERED captures! foreach my $line (@$apropos_lines_r) { if( $line =~ # Match like: "sha1pass (1) - Create a SHA1 password hash" m/\A (?'command_name' .*? ) (?'spacing_before_section' \s+ ) (?'section_number' \( $Section_of_interest_re \) ) (?'spacing_after_section' \s+ ) - (?'description' \s+ .+ # whole rest of line (incl. the newline) ) /xs ) { my $entry_r = # make a hashref: { %+, # Copy that magic hash of matched-RE items 'Whole_Line' => $line, 'Sort_Key' => lc ( $+{'command_name'} . " " . $+{'section_number'} ), } ; $entry_r->{'Sort_Key_Length'} = length $entry_r->{'Sort_Key'}; push @$man_pages_r, $entry_r; # Google "Schwartzian Transform" to understand this approach # to sorting-- namely, turning a string into a complex # structure, sorting the list of those structures # and than typically turning the structure back to the # original form. # (But in this extremely fancy case, in print_sorted_pages, # we'll actually piece together something new.) } } die "Nothing matches!?" unless @$man_pages_r; return $man_pages_r; } #====================================================================== sub man_pages_sorted { my($man_pages_r) = @_; my @man_pages_sorted = sort { # Sorting by length $a->{'Sort_Key_Length'} # '3' for 'tar' <=> $b->{'Sort_Key_Length'} or # Sorting by alpha $a->{'Sort_Key'} cmp $b->{'Sort_Key'} or # If we *somehow* make it here, sort by # comparing the law lines. $a->{'Whole_Line'} cmp $a->{'Whole_Line'} # Yup, this is THREE-level sorting! # Namely, if one level needs a tie-breaker, it falls # through to the level under it. } @$man_pages_r ; return \@man_pages_sorted; } #====================================================================== sub print_sorted_pages { my($man_pages_sorted_r) = @_; foreach (@$man_pages_sorted_r) { print join( "", # We move all the spacing to the left... # because I like the way that looks! $_->{'spacing_before_section'}, $_->{'spacing_after_section'}, " ", $_->{'command_name'}, " ", $_->{'section_number'}, $_->{'description'}, ); } return; } #====================================================================== __END__