brew search <user>/<repo> [substring]

For example `brew search homebrew/science` to get a list of all formulae
from that tap, even if not yet tapped.

`brew search <user>/<repo>/<substr>` or
`brew search <user>/<repo> <substr>` to grep for `<substr>`
inside of the tap `<user>/<repo>`.

Library/Contributions/manpages/brew.1.md

@@ -30,10 +30,11 @@ Note that these flags should only appear after a command.
   * `list`:
     List all installed formulae.
 
-  * `search`, `-S` <text>|/<text>/:
+  * `search` <text>|/<text>/:
     Perform a substring search of formula names for <text>. If <text> is
     surrounded with slashes, then it is interpreted as a regular expression.
-    If no search term is given, all available formula are displayed.
+    The search for <text> is extended online to some popular taps.
+    If no search term is given, all locally available formulae are listed.
 
 ## COMMANDS
 
@@ -272,10 +273,19 @@ Note that these flags should only appear after a command.
     If `--force` is passed, and there are multiple versions of <formula>
     installed, delete all installed versions.
 
-  * `search`, `-S` <text>|/<text>/:
+  * `search`, `-S`:
+    Display all locally available formulae for brewing (including tapped ones).
+    No online search is performed if called without arguments.
+
+  * `search`, `-S` <tap>:
+    Display all formulae in a <tap>, even if not yet tapped.
+    <tap> is of the form <user>/<repo>, e.g. `brew search homebrew/dupes`.
+
+  * `search`, `-S` [<tap>] <text>|/<text>/:
     Perform a substring search of formula names for <text>. If <text> is
     surrounded with slashes, then it is interpreted as a regular expression.
-    If no search term is given, all available formula are displayed.
+    The search for <text> is extended online to some popular taps.
+    If a <tap> is specified, the search is restricted to it.
 
   * `search --debian`|`--fedora`|`--fink`|`--macports`|`--opensuse`|`--ubuntu` <text>:
     Search for <text> in the given package manager's list.

Library/Homebrew/cmd/search.rb

@@ -4,6 +4,12 @@ require 'utils'
 require 'utils/json'
 
 module Homebrew extend self
+
+  # A regular expession to capture the username (one or more char but no `/`,
+  # which has to be escaped like `\/`), repository, followed by an optional `/`
+  # and an optional query.
+  TAP_QUERY_REGEX = /^([^\/]+)\/([^\/]+)\/?(.+)?$/
+
   def search
     if ARGV.include? '--macports'
       exec_browser "http://www.macports.org/ports.php?by=name&substr=#{ARGV.next}"
@@ -19,6 +25,23 @@ module Homebrew extend self
       exec_browser "http://packages.ubuntu.com/search?keywords=#{ARGV.next}&searchon=names&suite=all&section=all"
     elsif (query = ARGV.first).nil?
       puts_columns Formula.names
+    elsif ARGV.first =~ TAP_QUERY_REGEX
+      # So look for user/repo/query or list all formulae by the tap
+      # we downcase to avoid case-insensitive filesystem issues.
+      user, repo, query = $1.downcase, $2.downcase, $3
+      tap_dir = HOMEBREW_LIBRARY/"Taps/#{user}-#{repo}"
+      # If, instead of `user/repo/query` the user wrote `user/repo query`:
+      query = ARGV[1] if query.nil?
+      if tap_dir.directory?
+        # There is a local tap already:
+        result = Dir["#{tap_dir}/*.rb"].map{ |f| File.basename(f).chomp('.rb') }
+        result = result.grep(query_regexp(query)) unless query.nil?
+      else
+        # Search online:
+        query = '' if query.nil?
+        result = search_tap(user, repo, query_regexp(query))
+      end
+      puts_columns result
     else
       rx = query_regexp(query)
       local_results = search_formulae(rx)

share/man/man1/brew.1

@@ -38,8 +38,8 @@ Fetch the newest version of Homebrew from GitHub using \fBgit\fR(1)\.
 List all installed formulae\.
 .
 .TP
-\fBsearch\fR, \fB\-S\fR \fItext\fR|/\fItext\fR/
+\fBsearch\fR \fItext\fR|/\fItext\fR/
-Perform a substring search of formula names for \fItext\fR\. If \fItext\fR is surrounded with slashes, then it is interpreted as a regular expression\. If no search term is given, all available formula are displayed\.
+Perform a substring search of formula names for \fItext\fR\. If \fItext\fR is surrounded with slashes, then it is interpreted as a regular expression\. The search for \fItext\fR is extended online to some popular taps\. If no search term is given, all locally available formulae are listed\.
 .
 .SH "COMMANDS"
 .
@@ -298,8 +298,16 @@ Uninstall \fIformula\fR\.
 If \fB\-\-force\fR is passed, and there are multiple versions of \fIformula\fR installed, delete all installed versions\.
 .
 .TP
-\fBsearch\fR, \fB\-S\fR \fItext\fR|/\fItext\fR/
+\fBsearch\fR, \fB\-S\fR
-Perform a substring search of formula names for \fItext\fR\. If \fItext\fR is surrounded with slashes, then it is interpreted as a regular expression\. If no search term is given, all available formula are displayed\.
+Display all locally available formulae for brewing (including tapped ones)\. No online search is performed if called without arguments\.
+.
+.TP
+\fBsearch\fR, \fB\-S\fR \fItap\fR
+Display all formulae in a \fItap\fR, even if not yet tapped\. \fItap\fR is of the form \fIuser\fR/\fIrepo\fR, e\.g\. \fBbrew search homebrew/dupes\fR\.
+.
+.TP
+\fBsearch\fR, \fB\-S\fR [\fItap\fR] \fItext\fR|/\fItext\fR/
+Perform a substring search of formula names for \fItext\fR\. If \fItext\fR is surrounded with slashes, then it is interpreted as a regular expression\. The search for \fItext\fR is extended online to some popular taps\. If a \fItap\fR is specified, the search is restricted to it\.
 .
 .TP
 \fBsearch \-\-debian\fR|\fB\-\-fedora\fR|\fB\-\-fink\fR|\fB\-\-macports\fR|\fB\-\-opensuse\fR|\fB\-\-ubuntu\fR \fItext\fR