job-specifier: job: Add #:user keyword argument.

* src/mcron/job-specifier.scm (job): Add #:user keyword argument.
* doc/mcron.texi (Job specification): Document it.

2 files changed, 21 insertions, 16 deletions

diff --git a/doc/mcron.texi b/doc/mcron.texi
index 340faca..a59505d 100644
--- a/doc/mcron.texi
+++ b/doc/mcron.texi
@@ -271,11 +271,13 @@ on your system, as root.
 @cindex guile syntax
 @cindex syntax, guile
 @findex job
-In Guile-formatted configuration files each command that needs
-executing is introduced with the @code{job} function.  This function
-always takes two arguments, the first a time specification, and the
-second a command specification.  An optional third argument may contain
-a string to display when this job is listed in a schedule.
+In Guile-formatted configuration files each command that needs executing is
+introduced with the @code{job} function.  This function always takes two
+arguments, the first a time specification, and the second a command
+specification.  An optional third argument may contain a string to display
+when this job is listed in a schedule.  Additionally a @var{user} keyword
+argument can be supplied to use a different user than the one defined in
+@code{configuration-user} global variable.
 
 @cindex time specification, procedure
 @cindex procedure time specification
@@ -342,13 +344,12 @@ on Vixie syntax for this.
 @cindex job execution
 @cindex command execution
 @cindex execution
-The second argument to the @code{(job)} function can be either a
-string, a list, or a function.  In all cases the command is executed in
-the user's home directory, under the user's own UID.  If a string is
-passed, it is assumed to be shell script and is executed with the
-user's default shell.  If a list is passed it is assumed to be scheme
-code and is eval'd as such.  A supplied function should take exactly
-zero arguments, and will be called at the pertinent times.
+The second argument to the @code{(job)} function can be either a string, a
+list, or a function.  The command is executed in the home directory and with
+the UID of @var{user}.  If a string is passed, it is assumed to be shell
+script and is executed with the user's default shell.  If a list is passed it
+is assumed to be scheme code and is eval'd as such.  A supplied function
+should take exactly zero arguments, and will be called at the pertinent times.
 
 @subsection Sending output as e-mail
 @cindex email output
diff --git a/src/mcron/job-specifier.scm b/src/mcron/job-specifier.scm
index 9e13551..6dacece 100644
--- a/src/mcron/job-specifier.scm
+++ b/src/mcron/job-specifier.scm
@@ -212,7 +212,8 @@ go into the list.  For example, (range 1 6 2) returns '(1 3 5)."
 ;; finding the next legitimate time from the current configuration time (set
 ;; right at the top of this program).
 
-(define (job time-proc action . displayable)
+(define* (job time-proc action #:optional displayable
+              #:key (user configuration-user))
   (let ((action (cond ((procedure? action) action)
                       ((list? action) (lambda () (primitive-eval action)))
                       ((string? action) (lambda () (system action)))
@@ -231,11 +232,14 @@ go into the list.  For example, (range 1 6 2) returns '(1 3 5)."
                        "job: invalid first argument (next-time-function; "
                        "should be function, string or list)"))))
         (displayable
-         (cond ((not (null? displayable)) (car displayable))
+         (cond (displayable displayable)
                ((procedure? action) "Lambda function")
                ((string? action) action)
                ((list? action) (with-output-to-string
-                                 (lambda () (display action)))))))
+                                 (lambda () (display action))))))
+        (user* (if (or (string? user) (integer? user))
+                   (getpw user)
+                   user)))
     (add-job (lambda (current-time)
                (set! current-action-time current-time)  ;; ?? !!!!  Code
                
@@ -251,4 +255,4 @@ go into the list.  For example, (range 1 6 2) returns '(1 3 5)."
              action
              displayable
              configuration-time
-             configuration-user)))
+             user*)))