01/01: doc: Add elaborate package search example.

[Ludovic Courtès]

civodul pushed a commit to branch master
in repository guix.

commit b110869dd31f790bbc8c21149c9e5fb03acdc422
Author: Ludovic Courtès <address@hidden>
Date:   Thu Jan 7 14:46:11 2016 +0100

    doc: Add elaborate package search example.
    
    * doc/guix.texi (Invoking guix package): Add elaborate --search example
    using recsel and sexes.
---
 doc/guix.texi |   14 ++++++++++++++
 1 files changed, 14 insertions(+), 0 deletions(-)

diff --git a/doc/guix.texi b/doc/guix.texi
index c252f63..fc8a515 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -1434,6 +1434,7 @@ availability of packages:
 
 @item address@hidden
 @itemx -s @var{regexp}
address@hidden searching for packages
 List the available packages whose name, synopsis, or description matches
 @var{regexp}.  Print all the meta-data of matching packages in
 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
@@ -1477,6 +1478,19 @@ that deal with printed circuit boards; removing the 
angle brackets
 around @code{board} would further add packages that have to do with
 keyboards.
 
+And now for a more elaborate example.  The following command searches
+for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
+libraries, and prints the name and synopsis of the matching packages:
+
address@hidden
+$ guix package -s crypto -s library | \
+    recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
address@hidden example
+
address@hidden
address@hidden Expressions,,, recutils, GNU recutils manual}, for more
+information on @dfn{selection expressions} for @code{recsel -e}.
+
 @item address@hidden
 Show details about @var{package}, taken from the list of available packages, in
 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU