[dmd] 02/03: Export and document 'exec-command'.

[Ludovic Courtès]

civodul pushed a commit to branch master
in repository dmd.

commit 0d4d788a6f92c58a0968275f7b154aac23a944e1
Author: Ludovic Courtès <address@hidden>
Date:   Tue Jun 24 00:01:37 2014 +0200

    Export and document 'exec-command'.
    
    * modules/dmd/service.scm (exec-command): Export.  Augment docstring.
    * dmd.texi (Service De- and Constructors): Document it.
---
 dmd.texi                |   13 +++++++++++++
 modules/dmd/service.scm |   11 +++++++++--
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/dmd.texi b/dmd.texi
index 757a66e..d5fa881 100644
--- a/dmd.texi
+++ b/dmd.texi
@@ -826,6 +826,19 @@ calling the destructor; if it would not do that, killing 
the process
 in the destructor would immediately respawn the service.
 @end deffn
 
+The @code{make-forkexec-constructor} procedure builds upon the following
+procedure.
+
address@hidden {procedure} exec-command @var{command} @
+  [#:directory (default-service-directory)] @
+  [#:environment-variables (default-environment-variables)]
+Run @var{command} as the current process from @var{directory}, and with
address@hidden (a list of strings like @code{"PATH=/bin"}.)
+File descriptors 1 and 2 are kept as is, whereas file descriptor 0
+(standard input) points to @file{/dev/null}; all other file descriptors
+are closed prior to yielding control to @var{command}.
address@hidden deffn
+
 @c @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
 
 @node Service Examples
diff --git a/modules/dmd/service.scm b/modules/dmd/service.scm
index 2d99c1d..8b6266e 100644
--- a/modules/dmd/service.scm
+++ b/modules/dmd/service.scm
@@ -60,6 +60,7 @@
             handle-unknown
             make-forkexec-constructor
             make-kill-destructor
+            exec-command
             make-system-constructor
             make-system-destructor
             make-init.d-service
@@ -563,8 +564,14 @@ set when starting a service."
   (environ))
 
 (define* (exec-command command
-                       #:key directory environment-variables)
-  "Run COMMAND with the given settings."
+                       #:key
+                       (directory (default-service-directory))
+                       (environment-variables (default-environment-variables)))
+  "Run COMMAND as the current process from DIRECTORY, and with
+ENVIRONMENT-VARIABLES (a list of strings like \"PATH=/bin\".)  File
+descriptors 1 and 2 are kept as is, whereas file descriptor 0 (standard
+input) points to /dev/null; all other file descriptors are closed prior to
+yielding control to COMMAND."
   (match command
     ((program args ...)
      ;; Become the leader of a new session and session group.