guix package: Add 'guix search' alias.

* guix/scripts/search.scm: New file.
* Makefile.am (MODULES): Add it.
* po/guix/POTFILES.in: Add it.
* tests/guix-package-aliases.sh: Add test.
* doc/guix.texi (Invoking guix package): Document it and use it in a
couple of examples.

Makefile.am

@@ -227,6 +227,7 @@ MODULES =					\
   guix/scripts/install.scm			\
   guix/scripts/remove.scm			\
   guix/scripts/upgrade.scm			\
+  guix/scripts/search.scm			\
   guix/scripts/gc.scm				\
   guix/scripts/hash.scm				\
   guix/scripts/pack.scm				\

doc/guix.texi

@@ -2630,6 +2630,8 @@ For your convenience, we also provide the following aliases:
 
 @itemize
 @item
+@command{guix search} is an alias for @command{guix package -s},
+@item
 @command{guix install} is an alias for @command{guix package -i},
 @item
 @command{guix remove} is an alias for @command{guix package -r},
@@ -2953,12 +2955,13 @@ name: gmp
 @dots{}
 @end example
 
-It is also possible to refine search results using several @code{-s}
-flags.  For example, the following command returns a list of board
-games:
+It is also possible to refine search results using several @code{-s} flags to
+@command{guix package}, or several arguments to @command{guix search}.  For
+example, the following command returns a list of board games (this time using
+the @command{guix search} alias):
 
 @example
-$ guix package -s '\<board\>' -s game | recsel -p name
+$ guix search '\<board\>' game | recsel -p name
 name: gnubg
 @dots{}
 @end example
@@ -2973,7 +2976,7 @@ for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
 libraries, and prints the name and synopsis of the matching packages:
 
 @example
-$ guix package -s crypto -s library | \
+$ guix search crypto library | \
     recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
 @end example
 

guix/scripts/search.scm

@@ -0,0 +1,67 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2019 Ludovic Courtès <ludo@gnu.org>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (guix scripts search)
+  #:use-module (guix ui)
+  #:use-module (guix scripts package)
+  #:use-module (guix scripts)
+  #:use-module (srfi srfi-1)
+  #:use-module (srfi srfi-26)
+  #:use-module (srfi srfi-37)
+  #:export (guix-search))
+
+(define (show-help)
+  (display (G_ "Usage: guix search [OPTION] REGEXPS...
+Search for packages matching REGEXPS."))
+  (display (G_"
+This is an alias for 'guix package -s'.\n"))
+  (newline)
+  (display (G_ "
+  -h, --help             display this help and exit"))
+  (display (G_ "
+  -V, --version          display version information and exit"))
+  (newline)
+  (show-bug-report-information))
+
+(define %options
+  ;; Specification of the command-line options.
+  (list (option '(#\h "help") #f #f
+                (lambda args
+                  (show-help)
+                  (exit 0)))
+        (option '(#\V "version") #f #f
+                (lambda args
+                  (show-version-and-exit "guix search")))))
+
+(define (guix-search . args)
+  (define (handle-argument arg result)
+    ;; Treat all non-option arguments as regexps.
+    (cons `(query search ,(or arg ""))
+          result))
+
+  (define opts
+    (args-fold* args %options
+                (lambda (opt name arg . rest)
+                  (leave (G_ "~A: unrecognized option~%") name))
+                handle-argument
+                '()))
+
+  (unless (assoc-ref opts 'query)
+    (leave (G_ "missing arguments: no regular expressions to search for~%")))
+
+  (guix-package* opts))

po/guix/POTFILES.in

@@ -44,6 +44,7 @@ guix/scripts/package.scm
 guix/scripts/install.scm
 guix/scripts/remove.scm
 guix/scripts/upgrade.scm
+guix/scripts/search.scm
 guix/scripts/gc.scm
 guix/scripts/hash.scm
 guix/scripts/import.scm

tests/guix-package-aliases.sh

@@ -56,3 +56,5 @@ then false; else true; fi
 
 if guix remove -i guile-bootstrap -p "$profile" --bootstrap
 then false; else true; fi
+
+guix search '\<board\>' game | grep '^name: gnubg'