blob: 18ec0543ea94f05aa8b392c651190bba87d30416 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
|
(define-module (hnh util env)
:export (let-env with-working-directory))
(define-syntax let-env
(syntax-rules ()
[(_ ((name value) ...)
body ...)
(let ((env-pairs #f))
(dynamic-wind
(lambda ()
(set! env-pairs
(map (lambda (n new-value)
(list n new-value (getenv n)))
(list (symbol->string (quote name)) ...)
(list value ...)))
(for-each (lambda (pair) (setenv (car pair) (cadr pair)))
env-pairs))
(lambda () body ...)
(lambda ()
(for-each (lambda (pair) (setenv (car pair) (caddr pair)))
env-pairs))))]))
;; TODO this probably isn't threadsafe... pthreads(7) notes
;; that chdir is shared between all threads.
(define-syntax-rule (with-working-directory directory thunk)
(let ((old-cwd #f))
(dynamic-wind
(lambda ()
(set! old-cwd (getcwd))
(chdir directory))
thunk
(lambda () (chdir old-cwd)))))
|