diff options
Diffstat (limited to 'environment.scm')
| -rw-r--r-- | environment.scm | 75 |
1 files changed, 29 insertions, 46 deletions
diff --git a/environment.scm b/environment.scm index f2a8119..b340330 100644 --- a/environment.scm +++ b/environment.scm @@ -17,23 +17,33 @@ -;; This file defines the global variable current-environment-mods, and the -;; procedures append-environment-mods (which is available to user configuration -;; files), clear-environment-mods, modify-environment, and -;; parse-vixie-environment. The idea is that the current-environment-mods is a -;; list of pairs of environment names and values, and represents the cumulated -;; environment settings in a configuration file. When a job definition is seen -;; in a configuration file, the current-environment-mods are copied into the -;; internal job description, and when the job actually runs these environment -;; modifications are applied to the UNIX environment in which the job runs. +;; This file defines the variable current-environment-mods, and the procedures +;; append-environment-mods (which is available to user configuration files), +;; clear-environment-mods and modify-environment. The idea is that the +;; current-environment-mods is a list of pairs of environment names and values, +;; and represents the cumulated environment settings in a configuration +;; file. When a job definition is seen in a configuration file, the +;; current-environment-mods are copied into the internal job description, and +;; when the job actually runs these environment modifications are applied to the +;; UNIX environment in which the job runs. + +(define-module (mcron environment) + #:export (modify-environment + clear-environment-mods + append-environment-mods + get-current-environment-mods-copy)) + + + + ;; The env-alist is an association list of variable names and values. Variables ;; later in the list will take precedence over variables before. We return a ;; fixed-up version in which some variables are given specific default values -;; (which the user can override), and one variable which the user is not allowed -;; to control is added at the end of the list. +;; (which the user can override), and two variables which the user is not +;; allowed to control are added at the end of the list. (define (impose-default-environment env-alist passwd-entry) (append `(("HOME" . ,(passwd:dir passwd-entry)) @@ -66,6 +76,13 @@ +;; Each time a job is added to the system, we take a snapshot of the current set +;; of environment modifiers. + +(define (get-current-environment-mods-copy) + (list-copy current-environment-mods)) + + ;; When we start to parse a new configuration file, we want to start with a ;; fresh environment (actually an umodified version of the pervading mcron @@ -76,46 +93,12 @@ - ;; Procedure to add another environment setting to the alist above. This is used ;; both implicitly by the Vixie parser, and can be used directly by users in ;; scheme configuration files. The return value is purely for the convenience of -;; the parse-vixie-environment procedure below. +;; the parse-vixie-environment in the vixie-specification module (yuk). (define (append-environment-mods name value) (set! current-environment-mods (append current-environment-mods (list (cons name value)))) #t) - - - - -;; Procedure to act on an environment variable specification in a Vixie-style -;; configuration file, by adding an entry to the alist above. Returns #t if the -;; operation was successful, #f if the line could not be interpreted as an -;; environment specification. - -(define parse-vixie-environment-regexp1 - (make-regexp - "^[ \t]*([[:alpha:]_][[:alnum:]_]*)[ \t]*=[ \t]*\"(.*)\"[ \t]*$")) -(define parse-vixie-environment-regexp2 - (make-regexp - "^[ \t]*([[:alpha:]_][[:alnum:]_]*)[ \t]*=[ \t]*\'(.*)\'[ \t]*$")) -(define parse-vixie-environment-regexp3 - (make-regexp - "^[ \t]*([[:alpha:]_][[:alnum:]_]*)[ \t]*=[ \t]*(.*[^ \t])[ \t]*$")) -(define parse-vixie-environment-regexp4 - (make-regexp - "^[ \t]*([[:alpha:]_][[:alnum:]_]*)[ \t]*=[ \t]*$")) - -(use-modules (srfi srfi-2)) - -(define (parse-vixie-environment string) - (let ((match (or (regexp-exec parse-vixie-environment-regexp1 string) - (regexp-exec parse-vixie-environment-regexp2 string) - (regexp-exec parse-vixie-environment-regexp3 string)))) - (if match - (append-environment-mods (match:substring match 1) - (match:substring match 2)) - (and-let* ((match (regexp-exec parse-vixie-environment-regexp4 string))) - (append-environment-mods (match:substring match 1) #f))))) |